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Colombia - Final Regulatory Action
Mercury CAS number:
7439-97-6		 Date circular:
12/12/2020

Chemical name: Mercury

Final regulatory action has been taken for the category: Industrial

Final regulatory action: The chemical is Banned

Use or uses prohibited by the final regulatory action: Eradicate the use of mercury throughout the national territory in:

vAll industrial and productive processes within a period not exceeding ten (10) years (15 July 2023).

vFor mining within a maximum period of five (5) years (up to 15 July 2018).

Use or uses that remain allowed:

The regulation prohibits the use and marketing of mercury in industrial activities and establishes two terms depending on the activity. Therefore, currently the deadline for industrial uses other than mining has not been met; this is the reason why the use of mercury in the production of dental amalgam will continue until 15 July 2023.

The final regulatory action was based on a risk or hazard evaluation: Yes

Summary of the final regulatory action: The government of Colombia prohibited the marketing and use of mercury under Law 1658 of July 15, 2013 "Under which arrangements are established for the marketing and use of mercury in the different industrial activities of the country, requirements and incentives for their reduction and elimination, and other provisions are issued".

The purpose of the law is "In order to protect and safeguard the human health and preserve renewable natural resources and the environment, the use, import, production, marketing, handling, transportation, storage, final disposal and release into the environment of mercury in industrial activities, whatever they may be, must be regulated throughout the national territory".

Specifically, Article 3 establishes the measures to reduce and eliminate the use of mercury in the country as follows:

"Article 3. Reduction and elimination of the use of mercury. The Ministries of Environment and Sustainable Development; Mines and Energy; Health and Social Protection and Work, will establish the necessary regulatory measures that will allow to reduce and eliminate, in a safe and sustainable way, the use of mercury in the different industrial activities of the country. Eradicate the use of mercury throughout the national territory, in all industrial and productive processes within a period not exceeding ten (10) years and for mining within a maximum period of five (5) years… ".

The reasons for the final regulatory action were relevant to: Human health and environment

Summary of known hazards and risks to human health: INS MERCURY REPORT 2010_2011- SIVIGILA. (Annex II pages 1 and 8)

According to SIVIGILA, during 2010 and the first semester of 2011, there were 201 cases of mercury poisoning in Colombia, 134 cases in 2010 and 67 cases in the first semester of 2011. 96% of the cases were of occupational or accidental origin as follows: 85% (n = 171) occupational, 11% (n = 22) accidental.

SURVEILLANCE AND CONTROL PROTOCOL OF ACUTE MERCURY POISONING. (Annex III pages 2, 15 and 16)

Mercury is a toxic substance, that when entering the human body produces disorders, mainly at the central nervous system level. The presence of mercury in the air, water, soil and food (mainly fish) (1) in concentrations above the allowed limit has caused a serious public health problem in the country. Regions such as the Northeast of Antioquia, the South of Bolívar, Chocó, Santander, Nariño, Caldas, Vaupés, among others, carry out artisanal gold mining and for the final extraction of this precious metal, mercury is used. Its use occurs in an indiscriminate and poorly controlled way, a situation that has caused environmental contamination and has affected people's health. Exposure to mercury is also increased in industrial areas that use this substance.

Mercury contamination in Colombia is originated in the gold benefit processes in which the mineral containing the precious metal is extracted by joining with the mercury, forming the amalgam. During the process, mercury spills into water bodies and the environment. Subsequently, the amalgam obtained is burned in the open air, leaving the gold and releasing the toxic mercury vapors into the atmosphere. All these activities are performed very close to the miners' households, in such a way that families breathe a large part of the volatilized mercury vapor. Even remote populations can be affected by the mobilization of this substance.

Chronic mercury poisoning worries the scientific community due to the neurotoxic alterations, which initially manifest as subtle changes in the individual's behavior. This has become a challenge for medical personnel (Maizlish, 1994; Powell, 2000), since if poisoning is not suspected, it can progress to irreversible neurological damage, leaving disabling sequelae (Mergler, 2002). Studies carried out in exposed populations (occupational and general population) to mercury have made it possible to establish its relationship in the development of these manifestations (Fawer et al 1983, Piikivi 1989, Marh et al 1987).

The neuroepidemiological and toxicological study of the Suratá river pollutants carried out in the mining population of that region (Santander, 1992) raised the possible relationship of chronic exposure to mercury with the presence of neurological diseases (15). Tirado et al (2000) suggest that this form of exposure can cause neuropsychological and behavioral deficits in the population (16). In 1995, Olivero et al reported that the inhabitants of southern Bolívar presented signs of mercury intoxication such as hand tremors, neurological disorders and visual problems, among others. In this region, frequent cases of congenital malformations have also been reported, although without evidence of association with mercury exposure.

SCIENTIFIC, REGULATORY AND TECHNICAL EVIDENCE ON THE MERCURY PROBLEM AT THE NATIONAL AND INTERNATIONAL LEVEL OF THE HEALTH SECTOR AND OTHER RELATED SECTORS - ASSOCIATION AGREEMENT NO. 447 OF 2012 SIGNED BETWEEN THE MINISTRY OF HEALTH AND SOCIAL PROTECTION AND THE FOUNDATION FOR EDUCATION AND SOCIAL DEVELOPMENT - FES. (Annex IV pages 34, 48, 105, 106, 142, 143, 146, 147)

Mercury is currently used in products such as thimerosal-containing vaccines; skin lightening creams, thermometers, batteries, occupational uses such as dental amalgams, and gold extraction (page 34).

In conclusion, the reviewed studies in Colombia, have found inconsistent effects, possibly due to factors such as the population evaluated, habits, biomarker used, studied effects, or concentrations found; and have identified the consumption of fish or marine mammals as the main risk factor, being the most studied adverse health effect the neurological performance, especially motor skills. Regarding the results, there were not found differences with respect to age or gender, but it is possible to identify that the population with the highest risk are pregnant women due to the fetus susceptibility (page 48).

Investigations (pages 46, 47, 58)

On the Atlantic Coast, the study "Mercury on the Colombian Atlantic Coast: A limiting factor for development" makes a review of different investigations carried out in this part of the country, where the high concentrations of mercury in fish and humans are highlighted. One of the most important conclusions is that the yellow mojarra, the moncholo and the doncella have concentrations above the limit allowed according to WHO (0.5 µg, 1991).

Furthermore, in the Colombian Orinoquia in 1999 a study was carried out with the purpose of establishing the levels of mercury and the perception of risk in the Guainía gold mining population. Two groups were considered: 37 exposed people directly related to mining and 28 indirectly exposed, corresponding to family members and other local people. Such persons were surveyed to determine risk perception, and blood and hair samples were taken to establish the level of mercury. It was found that the work environment is not adequate, and was classified as precarious in the study. Furthermore, there is a lack of knowledge of the ecological risk and inadequate knowledge regarding the health effects caused by exposure to mercury. An average of 59.2 µg/L of mercury was found in blood and 26.9 µg/g in hair for the mining population. On the other hand, in the population exposed to mercury indirectly, average concentrations of 53.5 µg/L in blood and 22.86 µg/g in hair were found. In the comparison of the two groups, no statistically significant differences were found, reason why prevention and control programs should not be focused only on the mining population.

Regarding Antioquia, which is considered the most exposed department, different studies have been carried out, for example, in 2003 was published: "Measurement of mercury concentrations and environmental controls in the burning of amalgam from mining", focused on gold trading workers and their surroundings. For this purpose, the concentrations of mercury in the urine of workers and in the air of the places of sales and streets of Segovia were determined. Levels 14 times above average for industrial environments were found according to the American Conference of Governmental Industrial Hygienists (ACGIH) where in 1994 the maximum concentration was set at 25 µg/m3. Mercury levels in the air of places of sales were between 192.2 and 679.28 µg/m3, in the streets between 315.97 and 416.1 µg/m3 and in the urine between 47 and 420 µg/m3.

Moreover, in 2009 a study was carried out in Cartagena, Colombia to determine the concentration of mercury in canned tuna and was found that the concentrations of total mercury in the tuna samples varied between 0.09 and 2.59 ppm (0.86 ± 0.09 ppm), 34% of the analyzed samples exceeded the maximum limit for mercury established by Colombian legislation (1 ppm), and 59% of them exceeded the levels recommended by WHO (0.5 ppm). The results suggested that the consumption of canned tuna in the city of Cartagena represents a moderate risk for the general population in terms of exposure to mercury. Moreover, vulnerable groups (children, pregnant women, people with cardiac problems, and those seeking dietary and cardiovascular benefits) should limit their consumption, since the risk is high for these groups.

Additionally, other studies in Colombia have also shown that in the sites where mining is carried out fish with high concentrations of mercury can be found. In 2009, a study was carried out in the Ciénaga de Ayapel and in the San Pedro river, an area that has extensive nickel mining and gold mining. Mercury level measurements were made in fish and it was found that from a total of 45 fish species collected, 19 (42.2%) exceeded the maximum allowed concentration of 0.5 µg/g established by WHO as safe for human consumption. All of them were carnivorous species. However, to protect the vulnerable population (under 15 years of age, pregnant women and frequent consumers), the same organization has established a limit of 0.2 µg/g, thus the number of specimens above this new limit increased to 36 (80%), including specimens of non-carnivorous species (93).

In addition, given that the consumption of fish is part of the cultural traditions of many communities, studies have been carried out with indigenous populations that have a high consumption of fish in order to estimate the concentrations of mercury in fish and the population exposure.

Characterization of Mercury Poisonings (Pages 105-106)

As a result of the report from the Primary Data Generating Units (UPGD) to Notifying Units (UN) and District or Departmental Notifying Units (UND), the INS received the information and based on this, published the Bulletin of mercury poisoning in Colombia over 2007 - 2011 showing the results of the epidemiological surveillance of mercury poisoning since the report began across the country (179) [1].

As aspects to be highlighted, it is shown that during this period, 450 cases were reported, and during 2009, the highest number of notifications were presented with 159 cases. The department of Antioquia notified 407 cases during the 5 years study, been the main notifier, this trend was maintained during all the reviewing years, where Antioquia annually reported more than 90% of the national total cases (179).

Of the total of cases in the studied period, 85.55% correspond to men and 94.67% required hospitalization; the highest number of notifications were in the age group of 20 to 49 years, within this range the subgroups of 40 at 44 years and 45 to 49 years old presented the same percentage (14.67%) and the group from 25 to 29 years old 13.56%, which allows to deduce a relationship between intoxication and occupational activity (179).

The 79.33% of the poisoning cases were caused by respiratory route, 9.56% by oral route and 6.89% by the skin. Given this, it can be affirmed that mercury poisoning in the country is associated with the inhalation of metallic mercury vapors, a product of the burning of amalgam to obtain gold; and given the form of exposure that is permanent and at variable concentrations, the intoxication is predominantly chronic, with infrequent acute intoxication, but acutening of chronic symptoms due to the exposure to an unusual concentration of the pollutant occurred with some frequency (179).

Occupational exposure is the most frequent with 88.4% of reported cases, where mining and quarrying occupations are the ones with the highest number of cases (267) associated with the use of mercury as an input for gold mining (179).

The most significant conclusions indicate that the most frequent notifiers during the period were Antioquia, followed by Bogotá, Bolívar, Risaralda, Santander and Valle del Cauca. The highest percentage of intoxications reported were occupational, been respiratory the most frequent route of exposure, and according to the analysis by occupation, the highest number of intoxicated were miners or stonemasons (179).

1.In the technical meetings held by the FES foundation, it was also identified that there are some population groups that deserve special attention in relation to exposure to mercury, since they have a greater probability of exposure to dangerous levels, or because carriers of disease, the intoxication effects can be exacerbated (53). These groups are:

·Workers exposed to mercury

·General population next to sources of mercury contamination (mines, industries)

·Populations in areas contaminated by mercury, especially indigenous and riverine, whose main source of proteins is fish

·People using mercury-containing medications for a long time

·People with central nervous system diseases, patients with chronic kidney and bronco pulmonary failure

·Pregnant women and toddlers

In addition, the emphasis was on pregnant women, lactating women and children who have certain characteristics that, combined with the characteristics of mercury, make them the most vulnerable population groups.

Results of Studies in Colombia (pages 142, 143,144, 145, 146 and 147):

Year 1991:

Neuro epidemiological and neuro toxicological study of a mining population with chronic exposure to mercury. Objective: To determine if chronic environmental exposure to mercury is a risk factor for neurological diseases in the mining population of the Suratá river (Santander). Target population: Exposed - Miners, relatives and neighbors. Not exposed - General population. Suratá, Santander-Colombia. Results: Mercury concentrations in blood did not exceed the average standard, however, there were statistically significant differences between exposed and unexposed. In untreated water, the average was greatly exceeded in those exposed. The prevalence of events is higher in the exposed group; however, there are no statistically significant differences. An association was found between blood levels and extrapyramidal diseases and migraine.

Year 1995:

Study "Mercury in hair of different occupational groups in a gold mining area in the North of Colombia". Objective: To determine the magnitude of mercury contamination in the population of the South of Bolívar according to their occupation and the incidence on their health. Study population: 219 inhabitants of southern Bolívar and 27 people from Cartagena as a control group. Results: Differences were found in the concentration of mercury in hair according to occupation as follows: fishermen (5.23+-5.78) miners (2.83+-3.27) other activities (2.40+-2.02) control group (1.33+-0.74); fishermen data was statistically significant with the rest. There are no differences by sex and age.

Year 2000:

Study "Neuropsychological alterations due to occupational exposure to mercury vapors in El Bagre (Antioquia, Colombia)". Objective: To determine if the miners of El Bagre (Antioquia, Colombia) have neuropsychological and/or behavioral disorders as a result of occupational exposure to toxic mercury vapor. Study population: Cases: 22 healthy men occupationally exposed for more than three years. Controls: 22 healthy men not exposed to mercury with age and education-matched with cases. Results: In the group of cases, effects were found in intellectual damage (alteration of some neuropsychological functions), emotional (anxiety and depression) and neurological (amnesia, insomnia and tongue tremor) changes, with statistically significant differences than the control group, in which no effects were observed. There are no differences in all the tests.

Year 2001:

Study "Mercury levels and perception of risk in a gold mining population of Guainía (Colombian Orinoquia)". Objective: To determine the levels of mercury in hair and blood in a mining population of the department of Guainía and the perception of risk that this population has when using this element. Study population: 78 residents of the region related to mining, which consumed fish and water. The analysis divided exposed groups: individuals directly involved in mining activities and another group indirectly exposed with family members or people who carried out other activities in the village. Results: Mercury concentrations of 59.16 µg/l were found in blood on average (6.9-168) and in hair of 26.93 µg/g (3.0-89.2) in miners, while in indirectly exposed population levels were lower, although without statistically significant differences, 53.5 and 22.86 in blood and hair respectively. It is evident that they pollute the ecosystem, possibly due to deficits in the work environment and the lack of knowledge of the ecological risk; and have inadequate knowledge of the metal even though they perceive the risk.

Study: "Diagnosis of Mercury levels in employees and students of the Faculty of Dentistry, University of Antioquia, 1999". Objective: To determine the existence of biological mercury poisoning by quantifying the element in 24-hour urine samples in dentistry students and professors. Study population: workers and students at the Faculty of Dentistry of the University of Antioquia, and comparison with the biological index of exposure. Results: The 192 samples presented concentrations below 30 mg (intoxication) and 1.6% (3) had levels = 15mg, which is the limit value for the occupationally exposed population. The highest concentrations are in students and teachers (6.04). There is a significant positive correlation between the exposure time (academic semester) and the mercury concentration. Negative correlation at the level of teachers and graduation time.

Year 2003:

The study "Mercury in the Colombian Atlantic Coast: Limiting factor of development" makes a review of different studies carried out in this part of the country, where high concentrations of mercury in fish and humans are evidenced. One of the most important conclusions established that the population with the highest concentrations of mercury are the fishermen, followed by the miners. The reviewed studies found that exposure to mercury is associated with the following effects: headache, nausea, oral lesions, metallic taste, memory loss and irritability, intellectual damage, emotional changes (depression and anxiety), neurological disorders, amnesia, insomnia and tongue tremor in miners.

Year 2004:

Study "Management of dental amalgam in small and medium dental studios in Medellín, Itagüí, Envigado, Sabaneta and Bello". Objective: To characterize the occupational variables, the management of mercury and amalgam residues in small and medium dental studios in Medellín, Itagüí, Envigado, Sabaneta and Bello. Studied population: Dentists and studios with at least one and less than seven chairs and where dental amalgam was used (800). Results: Training of dental personnel to carry out safe practices. Occupational: 46% have not been tested in the last 5 years, of these 4% had levels above normal, although not at levels of intoxication. 86% of those surveyed refer to following a protocol, although it is found not to be true. They report no symptoms.

Year 2006:

Study "Determination of neuro-behavioral alterations in adults chronically exposed to mercury in the population of the municipality of Segovia, Antioquia, 2005". Objective: To establish the prevalence of neuro-behavioral alterations in people chronically exposed to mercury in the municipality of Segovia, Antioquia. Study population: 860 people over 15 years old, miners or not from Segovia, Antioquia. Results: 15.2% of the evaluated people had mercury concentrations in hair = 5 µg/g. The prevalence of symptoms is high in this population. Subjective: 9.5-44.5; Neuropsychiatric: 10.3-63.5; are lower in the group of people with mercury levels = 5 µg/g, however there are no significant differences, which suggests that tolerance has been generated.

Year 2007:

Study "Finding of Mercury in fish from the Ayapel swamp, Córdoba, Colombia". Objective: To determine the total mercury (Hg-T) concentrations in some species of fish from the Cienaga de Ayapel (Colombia). Study population: Six samples of the following fish: Bocachico (Prochilodus magdalenae), Pintao catfish (Pseudoplatystoma fasciatum), Yellow mojarra (Caquetaia kraussi), Tilefish (Sorubin cuspicaudus), Moncholo (Hoplias malabaricus), Pacora (Plagioscion surcellainamensis), Maiden (Ageneiosus caucanus) and Liseta (Leporinus muyscoruma). Results: The average levels of Hg-Ten in the evaluated fish was 0.288 +- 0.145, in carnivores it was 0.246 and in non-carnivores 0.184, which did not exceed the limit for human consumption established by WHO. However, the risk can be increased by the consumption of 0.12 kg of fish, mainly Ageneiosus caucanus or "Maiden", which had the highest concentration (0.504+-0.103mg Hg/kg). In dry season the concentrations are higher except for Doncella, Bocachico and Liseta. These last two would be the only ones suitable for human consumption according to WHO.

Study "Humans and crabs exposed to Mercury on the Atlantic Coast of Colombia: Impact of an abandoned chlor-alkali factory". Objective: To establish the impact of mercury in contaminated sediments on the in the Bay of Cartagena. Study population: Inhabitants of fishing communities between 6-85 years old and crabs (Callinectes sapidus and Callinectes bocourti) along the Caribbean coast (CoveñasTasajera). Results: Total mercury concentrations found in hair were 0.1-21.8 µg/m3, with average of 1.52; this was measured in different places where the highest values ??were from the residents of Caño del Oro (1.4), followed by Bocachica (1.2), Lomarena (0.7) and Tasajera (0.7), and there were significant differences. A similar trend was observed in crabs and the highest values ??were in those collected next to the abandoned chlor-alkali factory. It shows that contaminated sediments continue to drive the distribution of mercury in the food chain.

Year 2008:

Study "Behavioral and personality alterations due to occupational exposure to mercury in a group of gold miners from the Bagre Antioquia region". Objective: To evaluate behavioral and personality alterations in 25 people occupationally exposed to contamination and/or intoxication by metallic mercury in the municipality of El Bagre. Study population: 25 inhabitants of El Bagre, occupationally exposed, ages: 20 to 55 years. Results: Suggests that exposure to mercury generates behavioral and personality alterations.

Year 2009:

Study "Contamination by heavy metals in the Muña reservoir and its relationship with blood levels of Lead, Mercury and Cadmium and health alterations in the inhabitants of the municipality of Sibaté (Cundinamarca) 2007". Objective: To describe the relationship between blood levels, population health conditions, and heavy metal contamination in the Muña reservoir. Study Population: Population of Sibaté, Cundinamarca, ages: 10 to 49 years. Results: The greatest exposure to metals is from the consumption of fruits, vegetables, meat and milk grown near the reservoir; the consumption of fish is low. The most frequent symptoms related to Hg were: headache, mood disorders, feeling dizzy and hands tingling, among others. The average Hg in blood was 4.06 ug/L (1.7-13.5). No participant had levels above the average, although in 47.1% of them were found low concentrations.

Study "Risk in the management of dental amalgam in medium and small dental clinics in the department of Antioquia, Colombia". Objective: Describe and characterize the activities related to the management of mercury, amalgam and its residues in 107 clinics that provide oral health services. Study population: Clinics that provide oral health services, classified between medium and small (with less than five chairs or dental units in the same workplace). Results: 46% of the entities have high or very high risk. People who have had abnormal levels have not received any treatment. Ignorance is evident, thus academic institutions recommend implementing comprehensive and safe methodological actions in the short term to reduce the risk for staff, patients and the ecosystem.

Year 2010:

Study "Mercury contamination in humans and fish in the municipality of Ayapel, Córdoba, Colombia, 2009". Objective: To evaluate the concentrations of total mercury in hair of inhabitants of the municipality of Ayapel (Córdoba) and in fish caught in the Ayapel swamp. Study population: 112 riverian residents of the Ayapel swamp over 14 years of age (hair) and 45 fish (muscle tissue). Results: Concentrations in people (2.18+-1.77) above EPA recommendations in the study group, but in the control it was below the standard. The most prevalent symptoms were headache, lack of energy, and irritability. In fish the highest levels are found in Sorabin cuspicaudus (0.74+-0.19). Showing evidence between fish consumption and health effects.

Study "Detection of heavy metals in cattle, in the valleys of Sinú and San Jorge rivers, department of Córdoba, Colombia". Objective; To evaluate the presence of heavy metals (Pb, Cu, Cd and Hg) in the liver and right pectoral muscle of bovine, from farms in the Sinú and San Jorge area. Study population: Male, adult, mixed-breed zebu cattle, between 2 and 7 years old. Results: The concentrations of mercury and other metals (except copper) did not exceed the European and Mexican standards. The highest concentrations come from the cattle of San Jorge and the control group, although there are no significant differences. The registered values ??do not represent a risk to human health.

Year 2011:

Study "Neuropsychological alterations in schoolchildren in a municipality with high levels of environmental mercury vapor, Colombia, 2008-2009". Objective: To establish the prevalence of neuropsychological alterations in language, memory, executive functions and attention of schoolchildren between the second grade of primary school and the ninth grade of high school in the municipality of Segovia, Antioquia. Study population: 196 students from second grade to ninth year of high school in the municipality of Segovia, Antioquia. Results: 79.6% of schoolchildren present alterations in language comprehension, 77.6% in executive functions, 52.6% in visual attention, 43.9% in verbal fluency, 38.8% in short-term verbal memory and 31.1% long-term. Such percentages generate an alarm and indicate the need of intervention.

Study "Evaluation of the concentration of mercury in various brands of canned tuna marketed in the city of Cartagena de Indias." Objective: To determine the concentrations of mercury present in four brands of canned tuna in water, marketed in the city of Cartagena de Indias, evaluating their compliance with current national and international sanitary standards. Study population: four brands of tuna (three national and one imported), 41 samples. Results: 34% of the samples exceeded the Colombian legislation (1ppm) and 59%, WHO recommended parameter (0.5ppm). The can of imported tuna has lower levels with statistically significant differences.

Study "Determination of mercury levels in the air of dental studios and clinics in Cartagena Colombia". Objective: To determine the levels of mercury in the air of dental studios and clinics in the city of Cartagena, Colombia. Results: 51% of the clinics had levels above those recommended by the EPA (300 ng/m3), finding an average concentration of 1206 +-142 in air. In spittoons, 59% exceeded the standard 2538 +- 879. 51% of the cabinets exceeded the standard, finding an average of 2116 + 1551 ng/m3, the concentration in the cabinets reached 11394 ± 13.9 when patients were present.

DIAGNOSIS OF NATIONAL ENVIRONMENTAL HEALTH (Annex VI)

Natural sources of Mercury in Colombia (page 235)

A mercury deposit of volcanic origin is found in the department of Caldas, municipality of Aranzazu, which was discovered approximately in the fourth decade of the 20th century (INGEOMINAS, 1958). The first and only national mercury mine called "La Nueva Esperanza" mine was deployed in this region. In 1960, Ingeominas publications reported a reserve in the region of 35,000 pounds of the metal (INGEOMINAS, 1960), with an approximate annual production of 2,700 and 7,500 pounds of mercury for the years 1955 and 1957, respectively (INGEOMINAS, 1958). These figures apparently increased in the following years. Due to its exclusivity and high productivity, the deposit received great attention from the authorities in charge of monitoring the mining sector at the time. During a technical visit to the mine, the optimization of the facilities, the use of closed methods, and the relocation of workers' homes were recommended in order to reduce exposure to mercury, INGEOMINAS report March 1960. The previously mentioned confirms the imminent risk for the workers of the organization identified since that year, as well as the search for alternatives that would mitigate the said risk and therefore promote safe operations in the mine.

In 1977, the mine was closed due to health alterations detected in the workers of this area, associated with occupational exposure to mercury (Escobar, 2006). After the closure of the mine, in a study published in 1979, sediment, soil and rock samples were evaluated considering the territory where the mine operated and an area close by, finding abnormal concentrations of mercury in an extension of 1 by 25 km (Vesga and Prez, 1979).

Studies in humans (pages 243-245)

In Colombia, mercury measurements have been made in humans, mainly in workers and communities surrounding mining activities or adjacent to riverine areas. An interesting information comes from a study where pre-Hispanic samples were analyzed, corresponding to the Mesa de los Santos area in Santander, where mercury levels in hair were detected below 0.3 µg/g (Idrovo et al, 2002); These values can be used as a baseline time reference for future studies in the country. In contrast, today levels up to 76 (Olivero et al, 2008a) and 256 times higher (Idrovo et al, 2001) are detected. The above clearly indicates an increase in mercury levels in human samples, suggesting a relationship between human exposure to mercury with the industrialization and development processes in recent times.

Table 5.9. Mercury values in hair and blood samples in Colombia.

PlaceSourceLevelsAuthorSur de BolívarHair - fisherman5.23±5.78µg/gHair - miner 2.83±3.27µg/g Olivero et al, 1995Hair - people with another activity 2.40±2.02µg/gCartagenaHair1.33±0.74µg/gGuainíaBlood - miner59.1 µg/LBlood - not miners53.5 µg/LIdrovo et al, 2001Hair - miner26.93 µg/gHair - not miner22.86 µg/gCaimito, SucreHair4.91±0.55 µg/gOlivero et al, 2002Bahía de Cartagena Caño del OroHair1.5 µg/gOlivero et al, 2008a BocachicaHair1.4 µg/gOlivero et al, 2008aCoveñasHair1.2 µg/gOlivero et al, 2008aLomarenaHair0.7 µg/gOlivero et al, 2008aTasajeraHair0.7 µg/gOlivero et al, 2008aNote Source: Adaptation made by the author.

* Data was obtained from the studies corresponding to the following authors: Olivero et al, 1995; Idrovo et al, 2001; Olivero et al, 2002; Olivero et al, 2008a.

Health effects of mercury (pages 245- 247)

In Colombia, the neurological effects of mercury have been mainly described. In the routine information reporting systems on health services and the national epidemiological surveillance system, cases of acute mercury poisoning are mandatory. It is striking that despite the high exposure to the metal detected in different regions of the country, for 2010 only two acute metal poisonings were reported, one of which corresponded to mercury (SIVIGILA, 2010). In addition, most of the detectable cases of intoxication may correspond to chronic intoxication events that go unnoticed within the system, since these are not immediately notified.

5.2.4.1. Neurological effects. The neuroepidemiological study of the Suratá River, near the Vetas-California mining district, Santander, found chronic mercury poisoning in the population of this area associated with the presence of extrapyramidal alterations in the exposed group (Pradilla, 1992). Such alterations mainly consist of tremor, dystonia and coordination disorders, among others.

In another study developed in a mining population, the neurological symptoms developed between the working population and another unexposed population were compared; in this case, a significant increase of neuropsychological symptoms and behavioral alterations was found in the exposed group (Tirado et al, 2000).

Furthermore, a study carried out in Segovia, Antioquia, in 2005 found a significant association between elevated levels of methylmercury and the presence of neurological symptoms such as fine tremor in the eyelids and lips; the most frequent neurological findings in this group were tremor 11.5% followed by a positive Romberg's sign, in 5.7% of the cases, consisting in the inability of maintaining balance while the individual stands upright keeping the feet together, eyes closed and arms in front, (Cote M, 2006). Because Segovia is an area with high exposure to mercury, multiple intervention and improvement strategies have been developed by public and private entities, in order to increase the knowledge of the community and workers in issues and good practices of the use of mercury, as well as efficient alternatives. Six years after the mentioned study, another investigation was carried out in the region, emphasizing the perception of risk, in which 96.4% of the individuals participating in the investigation considered that mercury was a harmful element for health.

Those people who had a health dossier of toxic effects of mercury had a greater perception of risk and greater use of protective measures, 58.9% 246 used gloves, 30.4% a mask, and 60.7% used mercury recyclers. It is striking that despite all the aforementioned, around 50% of the sample studied did not previously receive training in good practices related to the use of mercury in mining (García et al, 2011). When conducting an evaluation of the symptoms that the population self-reported as secondary effects of exposure to mercury in Segovia, it was found that the main symptoms were tremors, decreased visual acuity, headache, and memory loss, in this order. (García et al, 2011).

However, Segovia, like most mining districts, has a social, political and cultural scenario that generates different barriers to effective communication between the community and the territorial and health authorities, therefore, the measures given by the public health authorities and government policies are not easily adopted by the mining population.

A research with an anthropological and social approach determined the disagreement of the mining union with regard to the norms imposed from the public sphere, since they feel that they have been developed without their participation, based on scientific research and without taking into account the role of the mining community (Aguilar, 2009). This scenario is easily extrapolated to other mining contexts, where the process of adopting appropriate practices from an environmental and sanitary point of view by the mining community has been frustrated.

Another research carried out in Puerto Berrio, Antioquia, focused on evaluating the neurological and ototoxic effects of mercury in the context of artisanal mining, compared the clinical findings of the mining population with individuals working in limestone mining; the first group presented neuropsychotoxic alterations in 16% of the cases vs 1.25% in the second group. In addition, a positive and significant relationship was determined between exposure time and mining seniority, with hearing impairments (Ocampo et al, 2004).

5.2.4.2. Other effects. A single study carried out in the country in 1996 has evaluated obstetric events related to exposure to mercury in gold mining. The prevalence of congenital malformations was 0.56%, abortions 6.2% and perinatal death in 3.4% (Alzate, 1996). When comparing the data obtained in the population exposed to mercury with the statistics on the prevalence of congenital malformations in the general population, it was found very similar values ??(prevalence between 1.80% and 3.12% in the general population) (Zarante et al. 2010). This last study takes into account sentinel centers for congenital malformations; therefore, the data obtained may overestimate the prevalence of the general population and not be comparable with the study of the mining population.

In addition, an investigation carried out at the beginning of the 90's, tried to evaluate the ocular effects of exposure to mercury in miners. It is a topic little explored worldwide and most research has been directed to evaluating the effects of methylmercury, considering alterations such as progressive decrease in visual acuity, alteration of night vision, color discrimination, among others (Collins et al, 247 2007). However, a study carried out in workers exposed to total mercury vapors also found a subclinical reduction in color discrimination (Urban et al, 2003).

The Colombian study reported an association between subtle changes between perimetry and the reduction in visual acuity with seniority in mining, although these changes were not adjusted for age. A proportion less than 10% of the sample presented abnormal values ??of mercury in urine, the previous was not associated with visual alterations; palpebral tremor was reported in 50% of the study population, positively associated with the frequency of daily exposure to mining work (De los Ríos, 1991).

CONGRESS GAZETTE NO. 156, 2011 (Annex VII - page 1 and 2)

Mercury is a powerful neurotoxin from a naturally occurring heavy metal, capricious and difficult to work with. At room temperature and pressure, it is a silvery-white liquid that evaporates rapidly. The most common form of human exposure to this metal occurs through two routes: a) Occupational, in which there is inhalation of inorganic mercury vapor from the burning of amalgam or the gold smelting; It is also caused by spills, by manipulation in the sale or during the process of manufacturing medical devices or the use in the process called amalgamation in mining. b) The ingestion of methylmercury (MeHg) through the diet, especially the consumption of contaminated fish.

In mining, mercury is widely used by small and artisanal mining, which uses it to recover gold, but due to the way used, most of it is discharged into rivers; this is how mercury is transformed into methylmercury when settling in aquatic environments; the ingestion of this compound affects the nervous system, the kidneys and the liver, causing mental disorders and damage to the motor and reproductive systems, speech, vision and hearing. It is especially worrying because it prevents the neurological development of fetuses, infants and children. When a woman consumes fish or shellfish that contain mercury, it accumulates in her tissues and takes several years to be excreted; and if during this period becomes pregnant, the fetus will be exposed to methylmercury inside the uterus, which can negatively affect over the time the growth of brain and nervous system, with alterations in cognitive thinking, memory, attention, language, fine motor skills, and visual spaces in such creatures.

Mercury ingestion has been widely shown to damage respiratory system, kidney, and motor function; its toxicity is so high that even with very low exposure levels serious damage to the nervous system can be caused. In addition, environmental pollution generated in water, soil, air and the detriment of the quality of life is added; as well as the ever growing challenges imposed by the green and sustainable markets for the commercialization of these products.

[1] This Bulletin was issued in 2012 and officially published in 2013. For further information please visit: https://repository.usta.edu.co/bitstream/handle/11634/2923/%5B32%5D%20Vigilancia%20epidemiol%C3%B3gica%20de%20la%20intoxicaci%C3%B3n%20por%20mercurio%20Colombia%202007%20a%202011.pdf?sequence=38&;isAllowed=y

Expected effect of the final regulatory action in relation to human health:

Reduce occupational and environmental exposure to mercury in humans.

Summary of known hazards and risks to the environment: PROTOCOL FOR THE SURVEILLANCE AND CONTROL OF ACUTE POISONING BY MERCURY (Annex III pages 2, 15 and 16)

The presence of mercury in the air, water, soil and food (mainly fish) (1) in concentrations above the permitted limits has caused a serious public health issue in the country. Regions such as Northeast Antioquia, South Bolívar, Chocó, Santander, Nariño, Caldas, Vaupés, among others, carry out artisanal gold mining and mercury is used for the final extraction of this precious metal. Its use occurs in an indiscriminate and poorly controlled way, a situation that has caused environmental contamination and has affected people's health. Exposure to mercury is also increased in industrial areas that use this substance.

Mercury contamination in Colombia is originated in the gold benefit processes in which the mineral containing the precious metal is extracted by joining with the mercury, forming the amalgam; during this process, mercury spills into water bodies and the environment. Subsequently, the amalgam obtained is burned in the open air, separating the gold and releasing the toxic mercury vapors into the atmosphere. All these activities are carried out very close to the miners' homes, in such a way that families breathe a large part of the volatilized mercury vapor. Even remote populations can be affected by the mobilization of this substance.

Although in Colombia the main source of contamination comes from the gold beneficiation process, the presence of mercury as a contaminant was made known for the first time in the country in 1976 in a study performed by the Cartagena Bay Environmental Protection Committee (COPAC) which evidenced the presence of mercury in shellfish, fish, water and sediments (mercury levels of 32 ppm) due to the mercury waste discharged from the electrolytic alkali plant in Colombia.

SCIENTIFIC, REGULATORY AND TECHNICAL EVIDENCE ON THE MERCURY PROBLEM AT THE NATIONAL AND INTERNATIONAL LEVEL OF THE HEALTH SECTOR AND OTHER RELATED SECTORS - ASSOCIATION AGREEMENT NO. 447 OF 2012 SIGNED BETWEEN THE MINISTRY OF HEALTH AND SOCIAL PROTECTION AND THE FOUNDATION FOR EDUCATION AND SOCIAL DEVELOPMENT - FES. (Annex IV pages 35, 46, 47, 57, 58, 81, 82, 143, 144, 145 and 146)

According to the report prepared by Columbia University for the United Nations Industrial Development Organization UNIDO in 2010, Colombia ranks as the country with the highest per capita mercury contamination from artisanal gold mining as a result of such activity. This report shows that mercury concentrations in air exceed by 1,000 times the chronic exposure limits in Antioquia, specifically in Segovia, Remedios, Zaragoza, El Bagre and Nechí. Despite this, the methodology used for the measurement must be critically evaluated, and afterwords comparison must be performed considering both results. (Page 35)

Studies (page 57)

In a review carried out in 2006 in freshwater fish in Colombia, it is indicated that according to the studies carried out to determine mercury concentrations, there is a direct relation between high concentrations in fish and the proximity to areas with direct influence of dumping of gold mining waters, with critical values found in the region of La Mojana and the northeastern zone of Antioquia, where almost all the samples presented values ??higher than the standard of 0.5 µg/g of mercury. The highest mercury concentrations were found in carnivorous species such as Moncholo (Hopliasmalabaricus), Maiden (Ageneiosuscaucanus) and Mojarra (Caquetaiakaussi) that are found in the upper part of the food chain. However, high levels were also found in detritivorous species such as Arenca (Triportheusmagdalenae) that present a considerable accumulation of the metal due to the way in which these species obtain their food from sediments, which present high levels of mercury.

Research results in Colombia (pages 143, 144, 145 and 146)

Year 2006:

Study "State of knowledge of concentrations of mercury and other heavy metals in freshwater fish from Colombia". Objective: To verify the effects of aquatic contamination with freshwater organisms and the evaluation of at least three parameters (heavy metals, temperature, effluents), using eight species of fish. Study population: Colombia, Species: Carassius auratus, Oreochromis spp., Piractus brachypomus, Prochilodus magdalenae, Astyanax fasciatus, Colossoma bidens, Gambusia affinis and Grundulus bogotensi. Results: Río Magdalena and its tributaries (Mojana) is the place where the contamination of fish in Colombia has been studied. The relation between the high concentrations in fish and the proximity to the direct influence of gold mining is evidenced. Critical values ??were found in La Mojana and Northeast Antioquia and high concentrations in carnivorous fish (Hoplias malabaricus, Ageneiosus caucanus and Caquetaia kaussi).

Study "Measurement of mercury concentrations and environmental controls in the burning of amalgam from mining". Study population: Sales workers in Antioquia. Results: Levels 14 times above the standard. In buying and selling areas: 192.2-679.28 mg/m3, in the streets: 315.97-416.1 and in urine: 47-420.

Year 2007:

Study "Mercury contamination from artisanal gold mining in Antioquia, Colombia: The most expensive per capita contamination in the world." Objective: To obtain information about the gold production methods and ways of releasing mercury to the environment in the municipalities of Segovia, Remedios, Zaragoza, El Bagre and Nechí. Results: In 2009, 11 companies legally imported 130 tons of metallic mercury. In Segovia, Remedios, Zaragoza el Bagre and Nechí there are 323 artisanal processing facilities producing between 10 and 20 tons of gold. Taking into account the average amount of mercury consumed according to the balance sheet and the interviews of the facility owners, the estimated amount of mercury in these artisanal facilities corresponds to 93 tons. Concentrations in urban air range between 300 (background) and 1 million ng/m3 (inside gold shops), in residential areas the most common concentration is 10,000 ng/m3, when the occupational limit according to WHO is 1000 ng/m3. The total release/emission of mercury in Colombia can reach 150 tons/yr, giving the country the dishonorable position of the first country in the world with the highest per capita mercury pollution from artisanal mining. It is required: Urgent government intervention to eradicate the supply of mercury to artisanal processing facilities. Facilities must be removed from urban centers, technology improved, and emissions reduced through technical assistance.

Study "Distribution of mercury in different environmental components in an aquatic ecosystem impacted by gold mining in northern Colombia." Objective: To determine the levels of Hg in different environmental matrices in this ecosystem and to evaluate the changes in the distribution of Hg throughout different sampling sites and stations, environmental assessment and human exposure. Target Population: Humans, Sediments, Water, Plankton, Fish, and Seston. Results: T-Hg levels were found in water, sediments, seston, phytoplankton and zooplankton: 0.33, 0.71, 1.20, 052, 0.94 respectively. The highest values were found in the dry season. Differences were found according to trophic position.

Year 2008:

Study "Contribution of locative and environmental conditions to the risk of mercury contamination in dental entities in Antioquia." Objective: To describe the locative and environmental conditions in 30 large dental entities in the department of Antioquia. Target population: 30 dental entities (85% of the population) that had five or more dental chairs or units in the same workplace. Results: Not all large entities provide services in adequate facilities or make good management of environmental variables. In 97% of the entities there is a latent risk of mercury contamination. Spills have occurred in 37% of the sites.

Year 2012:

Study "Mercury concentrations in muscle and liver tissue of fish collected along the Magdalena river, Colombia". Objective: To determine the concentration of total mercury in muscle and liver tissue in fish caught in the Magdalena river basin. Study population: 378 muscle and 102 liver samples. Results: The highest level of mercury in muscle tissue was found in the non-carnivore Pimelodus blochii, however, the carnivorous group had higher concentrations with significant differences. There are no significant differences in total mercury by species or genus.

Study "Concentrations of methylmercury in six species of fish from two rivers of Colombia". Objective: To determine if the fish chosen in La Miel and Nechí rivers differ in the concentration of methylmercury in the muscle. Study population: Six species of fish from two rivers (La Miel, Nechí): Sorubim cuspicaudus, Pseudoplatystoma magdaleniatum, Triportheus magdalenae, Pimelodus spp., Prochilodus magdalena, Leporinus muyscoru. Results: Fish from the market near to Nechí River had high levels of MeHg. Concentrations are highest in the Nechí river. Results suggest that pollution is not generalized in all river basins; highly contaminated fish reach the market in mining regions.

QUANTIFICATION OF ANTHROPOGENIC MERCURY RELEASES IN COLOMBIA (Annex V. pages 67, 68, 69 81 and 82)

Regarding releases and emissions, the report on the quantification of anthropogenic releases of mercury in Colombia contains the quantification of releases and emissions of mercury generated in the productive and service sectors in 2009. Compared to total releases of mercury, for the year 2009, this were 345,570 kg distributed as follows:

Table 44. Quantification of mercury releases in Colombia for 2009

SoilAirWaterWaste treatment from specific sectors /disposalBy-products and impuritiesWaste in general151,65074,42031,26045,40028,19014,650

Both in Table 44 and in Figure 7, it is observed that the most affected environmental matrices are the soil and air, which receive 226,060 kg, and, within the production process, the treatment of waste and by-products and impurities, the phases where the highest amount of mercury is released with 73,590 kg.

Figure 7. Distribution of mercury releases in the different matrices

According to the report, the largest mercury emitting sources in the country correspond to the category "Primary production of metals", (194.97 Ton/year,) "Chemical products" including: production of chlor-alkali and vinyl chloride monomers (PVC), (97.60 Ton/year); waste disposal and wastewater treatment (57.81 Ton/year); use and disposal of products containing mercury corresponding to commercial activities that involve importing the products (thermometers, electrical switches, light sources, batteries) with 44.305 tons/year. The most affected medium is air, followed by soil and water. These releases come in a high percentage from the primary extraction of metals, mainly gold, as presented in the following table.

Table 11. Estimated mercury releases by category

CategoriesEstimated Hg input, Kg Hg/yearEstimated Hg releases, Kg Hg/yearAirWaterSoilBy-products and impuritiesGeneral wasteWaste treatment / disposal, specific by sectorPrimary metal production194,97449,475.7417,291.20123,384.004822.400.7Chemical production97,59711,117.091,951.9519,348.6321,896.54043,283.23Waste disposal/landfill and wastewater treatment7,990918.773,293.833,312.110319.420Use and disposal of products with mercury content44,3058048.7511027.418543.5242.8812855.372059.98Fuel production3,519324.52571.790301.71456.20.00Other production materials4,6482,801.1000923.56923.560Waste incineration536485.21000051.28Crematories and cemeteries46382.50377.5000Metal recycling production0.310.100.100.10Production of products containing mercury0000000Energy consumption1,2671,16900098.420Total355,30074,42334,136154,96628,18714,65345,395

Additionally, this inventory highlights that Colombia produces lighting fixtures, but there are no official activity rate data to be able to quantify this subcategory. Manometers to measure blood pressure (mercury sphygmomanometer), contained in the category Use and disposal of products with mercury content, were not taken into account in the inventory because these are not produced in the country and all units are imported and marketed. Furthermore, entry into the country is made under a tariff heading that covers many other products, making discrimination impossible for quantification purposes. The category of gold extraction with amalgamation and without the use of a retort is the activity that uses and releases the greatest amount of mercury in the country, being the artisanal miners lack of knowledge, the deficiency in environmental controls and inadequate mercury management the factors responsible for the situation. In addition to this, it should be noted that artisanal miners in the country believe that the greater the amount of mercury used, the greater the recovery of gold.

NATIONAL ENVIRONMENTAL HEALTH DIAGNOSIS - Annex VI (pages 237-243)

Mercury exposure assessment

Following, mercury concentrations in different environmental matrices are presented in maps, tables and graphs. For further information please see Annex VI.

Figure 5.3. Map of mercury levels in sediment, Colombia

Note: The map is displayed at page 23 of Colombia's FRA notification on mercury available at: www.pic.int/Portals/5/download.aspx?d=UNEP-FAO-RC-FRA-NOTIF-Mercury-7439976-Colombia-20200506.Sp.pdf

Source: the author.

*Data obtained from studies of Sarmiento et al, 1999; Marrugo J et al, 2010; Alonso, 2000.

Table 5.5. Mercury evaluation (ng/ml) in river Cauca waters according to monitoring point 1995-2008

StationHg[ng/ml]%RSDPuente Hormiguero14.663.4Paso del comercio2.793.5Juanchito16.024.1Media Canoa1.793.9Yotoco23.333.0Puerto Isaacs1.693.8Vijes2.631.6Note Source: Vásquez A. Evaluation by atomic absorption spectrometry of mercury in waters of the southern section of the Cauca River [Thesis]. Santiago de Cali, 2001.

Table 5.6. Analysis of total mercury in sediments of Cauca River

11/15/9505/22/9609/04/9607/30/97Sampling stationConcentration (ng/g)%RSDConcentration (ng/g)%RSDConcentration (ng/g)%RSDConcentration (ng/g) %RSDJuanchito107.1310.0338.2739.0341.8171.27966.5621.6Paso del comercio194.7521.0434.7958.82817.6631.3267.5981.2Puerto Isaacs208.6413.2265.3418.21645.1691.1267.5981.6Paso de la Torre195.3720.1145.5301.0217.9881.3885.3881.1Vijes188.6043.3113.8161.292.9611.4651.2303.1Yotoco175.5946.5111.6160.1512.3291.11092.3801.3Media Canoa1095.0640.0584.7794.2650.1320.1910.5802.2

Note Source: Rada MP. Study and evaluation of the degree of contamination by Cadmium, Mercury and Lead in waters, fish and sediments of the Rio Cauca by atomic absorption spectrometry [Thesis]. Santiago de Cali: Universidad de Valle, 1998.

Table 5.7. Mercury concentrations found in samples from Cauca River

Sampling pointConcentration (ppb)Puente Hormiguero12.8Antes Canal CVC-Sur4.92Después Canar CVC-Sur4.50Bocatoma Puerto Mallarino11.6Puente de Juanchito2.42Salida A Residuales PTAR-C4.50Desembocadura del río Cali en río Cauca3.25Note Source: Correa WA. Speciation of Lead, Chromium and Cadmium with XAD-16 amberlite resin and quantification of mercury in waters of the Cauca River in Santiago de Cali by atomic absorption spectrometry [Thesis]. Santiago de Cali, 2009.

Figure 5.4. Mercury concentrations in soils of Bucaranga metropolitan area parks

Note Source: Muñoz FA. Determination of mercury in soils of Bucaramanga, using a prolizer coupled to a mercury detector based on atomic absorption spectroscopy unlike Zeeman [Thesis]. Bucaramanga: Industrial University of Santander, 2006.

Table 5.8. Mercury concentration in fish in Colombia.

PlaceFish typeLevelsAuthorAyapel, Córdoba2.18±1.77 µg/g (max. 12.76) fresh weightGracia et al, 2010Carnivores0.100±0.006 mg/gBahía de CartagenaOmnivores0.076±0.014 mg/gOlivero et al, 2009Detritivores0.028±0.001 mg/g0.288±0.145 mg kg-1fresh weightCiénaga de Ayapel, CórdobaCarnivores0.346±0.133 mg kg-1 fresh weight Marrugo J et al 2007Non-carnivores0.184±0.102 mg kg-1 fresh weightCga de Ayapel, Mojana0.298 + 0.148 mg/g, fresh weightMarrugo J et al, 2010Carnivores0.160-0.301 mg/g Mojana 0.346 ± 0.171 mg g_1 fresh weight ¥Non-carnivores0.155 ± 0.108 mg g_1 fresh weight0.146 ± 0.102 mg g_ fresh weight ¥ San Benito0.346±0.262 µg/g fresh weight ¥ 0.386± 0.260 µg/g fresh weight Ayapel0.332±0.125 µg/g fresh weight ¥ 0.370±0.123 µg/g fresh weight San Marcos0.286±0.167 µg/g fresh weight ¥ Marrugo J et al, 20080.296±0.167 µg/g fresh weight Guaranda0.253±0.168 µg/g fresh weight ¥ 0.268±0.168 µg/g fresh weight Caimito0.228±0.153 µg/g fresh weight ¥ 0.240±0.165 µg/g fresh weight Majagual0.106±0.054 µg/g fresh weight ¥ 0.117±0.057 µg/g fresh weight Sucre0.088±0.057 µg/g fresh weight ¥ 0.091±0.059 µg/g fresh weightBahía de CartagenaDetection levels at 852 mg/kg dry weight Alonso et al, 2000PlaceFish typeLevelsAuthorCiénaga Grande de Santa MartaDetection levels at 68 mg/kg dry weightAlonso et al, 2000Río Nechi40 to 934 ng/g¥Álvarez et al, 2012Río la Miel8 to 92 ng/gNote Source: Adaptation made by the author.

* Data have been extracted from studies of the following authors: Gracia et al, 2010; Olivero et al, 2009; Marrugo J et al 2007; Marrugo J et al, 2010; Marrugo J et al., 2008; Alonso et al, 2000; Álvarez et al, 2012.

** Total mercury was measured in all cases, except those indicated with ¥, in which methylmercury was measured

CONGRESS GAZETTE NO. 156, 2011 (Annex VII - page 3)

Studies conducted by the Government of Antioquia in the municipalities of Segovia and Remedios, in the Northeast of the department, found a concentration of mercury of approximately 340 µg/m³ in the air (300 times higher than the guideline of the World Health Organization for public maximum exposure to vapor of mercury). Approximately 26 to 6,118 ppm of Hg is discharged into rivers by miners in the region.

Additionally, the main food of these communities is fish, which has been shown to be affected by the emission of mercury. Studies completed by Corantioquia, the University of Antioquia, and the University of Cartagena have revealed a concentration above 1.06 µg Hg/g in most of the species found in the rivers of the surrounding area.

Expected effect of the final regulatory action in relation to the environment:

Reduce the anthropogenic releases and emissions of mercury to the environment.

Date of entry into force of the final regulatory action: 15/07/2013

Date of prohibition of the use of mercury in mining: July 15, 2018.

Date of prohibition of the use of mercury in other industrial activities: July 15, 2023 (The only industrial activity that is currently allowed to use mercury in Colombia is the manufacture of dental amalgams).