Rio Grande, the southernmost Brazilian port and industrial center, is marked by mercurypolluted ground cover. This pollution varies spatially, with levels exceeding 1,000 lg kg-1 in 30% of the urban territory. The risk of Hg impact as a result of deliberate and involuntary geophagy is increased by restrained urban conditions in combination with the large proportion of the population living at lowincome levels. Laboratory tests have demonstrated that ingestion of Hg-polluted soil by rats results in significant alterations in animal health such as stagnation in body weight increase, and significant mercury accumulation in the liver and kidney. The consumption of Hg-contaminated urban soil also provoked changes in hematological profiles of experimental animals by increasing the number of platelets. The present study indicates the potential for the local population of Rio Grande living in mercurypolluted districts, specifically young children, to experience health disturbances.

Environment International, 2007

Mercury is a hazardous metal responsible for environmental contamination and human intoxication. Methylmercury, a very toxic organic compound, bioaccumulates through food chain, and is responsible for chronic mercury exposure of riverside Amazonian communities with a diet rich in fish. Uncertainties about the reference exposure dose that could have damaging consequences for nervous system development makes necessary the biomonitoring of these Amazonian populations, especially children. In this work, a comparative study was performed in exposed and non-exposed children living in the Amazon. A total of 168 children were analyzed to find possible correlations between gender, age, location, and hair mercury content. For each location, no statistically significant differences (P b 0.05) were detected for gender and age versus mercury content. However, mean mercury levels in hair samples may indicate a tendency of boys to average higher hair concentrations. Also, in the community with highest levels of mercury, the limit of 10 μg/g of mercury was surpassed by 65% of 2-6 years and 50% of 7-12 years children but only by 27% of 0-1 year babies, pointing to a lower bioaccumulation and/or the existence of a protection mechanism in babies. Log normal distributions of mercury concentrations for each location showed that children from populations under influence of gold mining activity contain the highest mercury levels in hair samples, though this intoxication may have decreased when compared to previous studies. Knowledge originated by this monitoring will better assist in the development of prevention strategies and government actions targeting the mercury contamination of Amazonian environment.

Science of The Total Environment, 2009

A mercury-cell chlor-alkali plant operated in Estarreja (North-western Portugal) for 50 years causing widespread environmental contamination. Although production by this process ceased in 2002, mercury contamination from the plant remains significant. The main objective of this study was to investigate mercury impact on the nearby environment and potential risks to local population. To assess the level of contamination soil samples were collected from agricultural fields in the vicinity of the plant, extending the study by taking samples of the predominant vegetation suitable for animal and human consumption, water samples, and fish species from a nearby coastal lagoon, to gain a preliminary insight into the potential for contamination of the terrestrial and aquatic food web. To determine population exposure to mercury, hair samples were collected from local residents. Total mercury concentration in the 0-15 cm layer of soil was found to be highly variable, ranging between 0.010 and 91 mg kg − 1 , although mercury contamination of soils was found to be restricted to a confined area. Lolium perenne roots contained between 0.0070 and 2.0 mg kg − 1 , and there is evidence that root systems uptake mercury from the soil. Levels of mercury in the aerial parts of plants ranged between 0.018 and 0.98 mg kg − 1 . It appears that plants with higher mercury concentration in soils and roots also display higher mercury concentration in leaves.

Applied Geochemistry, 2011

Almadén, Spain, has the most important known cinnabar deposits, which have provided a third of the entire world production of Hg, and has been the scene for numerous studies on Hg. This mining district includes several mines where cinnabar has been extracted in the past two millennia as well as facilities related to the production of primary Hg. The aim of the work is to evaluate the spatial distribution of Hg in the soil-plant system within an area where intense activity occurred over a long period. An abandoned metallurgical plant from the 17th-18th centuries was chosen as the study area, situated in Almadenejos a distance of 12 km from Almadén. Nowadays, this plot is covered with cinnabar mine tailings and it is used by village inhabitants for livestock grazing. The area has elevated Hg concentrations of natural origin and from human activities. Soil parameters are similar within the study area; however, data reveal high variability in total and available Hg concentrations in soils, making it difficult to establish a trend. Marrubium vulgare L. has been studied due to its abundance in the plot, and there is no evidence of phenological toxicity. In spite of elevated Hg concentrations, high biological activity is found in the sampled soils. All these characteristics, spatial variation, high Hg concentration, good biological activity, make this a particularly good area for studies involving Hg.

Open Journal of Soil Science, 2013

During the past four decades, mercury (Hg) research focused on fish consumption has explained less than 22% of Hg in human blood. One overlooked exposure pathway for infants and young children is the concentration of Hg in soils. Although 75% of the U.S. population lives in urban areas near industrial facilities, minimal data exist regarding the concentration and speciation of Hg in residential soils. Chronic exposure through ingestion of low concentrations of Hg in soils may explain a portion of the blood Hg levels noted in infants. Methods: Three relatively unexposed residential sites in a suburban community were selected. The primary route of contamination was atmospheric deposition. Soils were digested in a nitric acid-hydrofluoric acid solution and analyzed by cold vapor atomic absorption spectrophotometry. Measured concentrations of total Hg in local suburban soil samples were compared to levels measured in a national study of 27 remote and rural sites. The Al-Shahristani pharmacokinetic model, developed after the 1971 Iraqi Methyl Hg poisoning incident, was used to calculate the blood Hg concentration in a hypothetical year-old infant. Results: Soil samples contained Hg concentrations ranging from 0.01 to 0.24 ppm w . The distribution of Hg in the soil samples was non-linear and non-normal. The mean soil Hg concentrations at the three locations were 0.08, 0.05 and 0.08 ppm. Calculated blood Hg concentrations for a 10 kg, year-old infant due to ingestion of soil (200 mg/day) containing 0.2, 0.4 and 0.8 ppm Hg were 0.08, 0.17 and 0.26 μg/L, respectively. Conclusions: The pilot study data appear to support the hypothesis that chronic, low-level soil ingestion may be a significant source of Hg for infants. Further study is warranted.

Environmental Science and Pollution Research, 2015

Mercury (Hg) contamination is an issue of concern in the Amazon region due to potential health effects associated with Hg exposure in artisanal gold mining areas. The study presents a human health risk assessment associated with Hg vapor inhalation and MeHg-contaminated fish ingestion, as well as Hg determination in urine, blood, and hair, of human populations (about 325 miners and 321 non-miners) from two gold mining areas in the Brazilian Amazon (São Chico and Creporizinho, Pará State). In São Chico and Creporizinho, 73 fish specimens of 13 freshwater species, and 161 specimens of 11 species, were collected for total Hg determination, respectively. The hazard quotient (HQ) is a risk indicator which defines the ratio of the exposure level and the toxicological reference dose and was applied to determine the threat of MeHg exposure. The mean Hg concentrations in fish from São Chico and Creporizinho were 0.83± 0.43 and 0.36±0.33 μg/g, respectively. More than 60 and 22 % of fish collected in São Chico and Creporizinho, respectively, were above the Hg limit (0.5 μg/g) recommended by WHO for human consumption. For all sampling sites, HQ resulted from 1.5 to 28.5, except for the reference area. In Creporizinho, the values of HQ are close to 2 for most sites, whereas in São Chico, there is a hot spot of MeHg contamination in fish (A2-São Chico Reservoir) with the highest risk level (HQ=28) associated with its human consumption. Mean Hg concentrations in urine, blood, and hair samples indicated that the miners group (in São Chico: urine=17.37 μg/L; blood=27.74 μg/L; hair=4.50 μg/g and in Creporizinho: urine=13.75 μg/L; blood=25.23 μg/L; hair: 4.58 μg/g) was more exposed to mercury compared to non-miners (in São Chico: urine = 5.73 μg/L; blood = 16.50 μg/L; hair=3.16 μg/g and in Creporizinho: urine= 3.91 μg/L; blood=21.04 μg/L, hair=1.88 μg/g). These high Hg levels (found not only in miners but also in non-miners who live near the mining areas) are likely to be related to a potential hazard due to exposure to both Hg vapor by inhalation and to MeHg-contaminated fish ingestion.

Environmental Geology, 2009

This study aims at assessing the extent of total mercury (Hg) contamination in urban and agricultural soils under long-term influence of a chlor-alkali plant, located at about 1 km away from a town centre. Moreover, it aims at identifying the main factors controlling Hg contents' distribution and associated potential hazards to environment and human health. The median value of total Hg for soil surface layer (0-10 cm) was 0.20 mg/kg (data ranging from 0.050 to 4.5 mg/kg) and for subsurface layer (10-20 cm) 0.18 mg/kg (data ranging from 0.046 to 3.0 mg/ kg). The agricultural area showed higher Hg concentrations (ranging from 0.86 to 4.5 mg/kg) than urban area (ranging from 0.05 to 0.61 mg/kg), with some results exceeding target values set by the Dutch guidelines. Mercury concentrations observed in the studied area are more likely to be associated with the influence of the chlor-alkali plant and with the use of historically contaminated sludges and water from a nearby lagoon in agriculture, than to the impacts of urban development. The statistical correlations between Hg concentrations and soil properties suggest that anthropogenic metal sources should influence the spatial distribution more than the geological properties. Although the Hg emissions were drastically reduced 10 years ago, the area under influence of the chlor-alkali plant is still facing potential health and environmental threats arising from soil contamination.

Environmental Research, 2000

Cross-sectional studies were conducted in three riverside communities in the state of Para H in the Amazon Region of Brazil. Two of these communities, Bras1H lia Legal and Sa o Lu1H s do Tapajo H s, are located in a watershed exposed to mercury pollution from artisanal gold mining, and the third, Santana do Ituqui, is outside this area. The studies were based upon a community census and included all persons volunteering for participation in each community. All participants were surveyed by questionnaire for health history, occupation, residence, and diet. Clinical evaluations were also done on each subject, along with collection of blood, urine, feces, and hair. Fish samples were collected to represent the most frequently consumed species. Mercury was measured in hair and Ash. Although no signs or symptoms of overt mercury intoxication were observed, persons in Bras1H lia Legal and Sa o Lu1H s do Tapajo H s had higher levels of mercury in hair than residents of Santana de Ituqui, located out of the risk area. Levels of mercury in Ash were below Brazilian health guidance limits, but the high rates of Ash consumption among these populations raise concerns for the possible effects of chronic exposure, especially among young children and women of childbearing age.

Brazilian Journal of Medical and Biological Research, 2006

Four populations in the Amazon area were selected for a comparative study of mercury-exposed and non-exposed populations: São Luiz do Tapajós, Barreiras, Panacauera, and Pindobal Grande. The highest mercury levels in human hair samples were found in São Luiz do Tapajós and Barreiras, greatly exceeding the limits established by the World Health Organization. Panacauera showed an intermediate level below 9 µg/g. This was the first comparative and simultaneous evaluation of mercury exposure in the Amazon area. Also, thanks to this type of monitoring, we were able to eliminate the uncertainties about the reference dose. On the basis of these data, we can conclude that the mercury levels detected in exposed populations of the Tapajós River basin may be dangerous not only because they are above the World Health Organization limits, but also because the simultaneous mercury detection in non-exposed populations with similar characteristics provided a valid control and revealed lower mercury levels. Our results support the importance of continuous monitoring in both exposed and non-exposed populations.

Science of The Total Environment, 2006

People in developing countries are often considered at greater risk of mercury (Hg) poisoning due to a variety of factors including a lack of awareness regarding their occupational risks. Individuals requiring urine mercury (U-Hg) analysis at the Center for Toxicological Investigations of the University of Carabobo (CITUC), between 1998 and 2002 were studied to identify demographic characteristics associated to U-Hg levels. The studied population included individuals with a history of exposure (or related exposures) to Hg processes, and was comprised of 1159 individuals (65 children, 1094 adults) ages 0.58-79 years old, mean 36.63F12.4. Children's geometric mean U-Hg levels were 2.73 Ag/g Creatinine (Ct) and in adults 2.55 Ag/g Ct. The highest frequency of adults' occupations were shipyard workers (35.47%), dentists (23.5%), lab technicians (11.43%), dental employees 10.42% and miners (10.2%). Chemical laboratory technicians had the highest mean U-Hg (4.46 Ag/g Ct).

Mercury (Hg) is a global contaminant posing severe risks to human health worldwide. The aim of this study was to assess the levels of total Hg (T-Hg) in human hair and fish in the Caqueta River, at the Colombian Amazon, as well as to determine fish consumption-based risks for T-Hg ingestion. T-Hg levels were measured using a direct mercury analyzer. The overall mean T-Hg level in hair for humans in the Colombian Amazon was 17.29 µg/g. Total mercury ranged from 1.2 µg/g to 47.0 µg/g, with 79% of the sampled population having Hg concentrations greater than 10 µg/g hair. The results indicate that 100% of examined individuals had hair mercury concentrations exceeding the USEPA reference dose of 1 μg/g. Also, 94% of the individuals had mercury concentrations more than the WHO "threshold" level (5 μg/g). High T-Hg concentrations in fish were detected in Cichla o cellaris (1.60±0.30 µg/g), Hoplias malabaricus (0.72±0.04 µg/g), Platynematichthys notatus (1.05±0.05 µg/g), Calophysus macropterus (0.80±0.12 µg/g), and Pseudoplatystoma fasciatumpunctifer (0.65±0.35 µg/g) whereas the lowest (0.10 µg/g) appeared in Pinirampus pirinampu, and Mylossoma duriventre. In terms of Hg exposure due to fish consumption, these species are a risk for Hg-related health problems. In short, High amounts of T-Hg were found in samples of human hair, and fish is the food that most contributed to dietary Hg exposure. Our results suggest that the population of the Colombian Amazon should not eat fish that have high levels of Hg, and breast feeding should be reduced to protect children health.

Bulletin of Environmental Contamination and Toxicology, 2002

Environment and Ecology Research, 2013

As developing countries to become industrialized and urbanized, heavy metal pollution is likely to reach disturbing levels. These countries should learn from the mistakes of the developed nations and recognize that rapid deterioration of the environment can occur. There is a lack of data on the nature and extent of metal pollution either at local and regional level, particularly to assist in the understanding of metal cycling in the environment. Although most countries recognize the need to combat pollution, environmental, controls are either nonexistence or inadequate. So in this article we emphasized on one of the most important environment pollutant (Hg) and effect of mercury on the human health and at the end of the article some important and easy ways for preventing mercury hazards will be recommended.

23(Supl), 2018

Objective. To evaluate the distribution of total mercury (THg) in surface sediments, fish, hair, rice plants, and macrophytes, as well as the geoaccumulation index by THg in sediments and the risk potential for fish consumption in different municipalities affected by gold mining activities that have developed around in the Mojana region, Colombia. Materials and methods. The THg concentration was determined by thermal decomposition, using a direct DMA-80 mercury analyzer. Results. On average, the concentrations of THg in fish was 0.223±0.027 μg/g. Of the total fish samples, 11.6% exceeded the permissible limit established by the World Health Organization (0.5 μg/g), being 4.2% for non-carnivorous species and 7.4% for carnivorous species. Of the fish species, 76.9% showed risk index (HI) values greater than 1. The Geoaccumulation Index (Igeo) in sediments shows a contamination degree from non-polluted to moderate pollution for the different sampling stations. Hair THg concentrations ranged between 0.17-8.8 μg/g. Of the population, 47% exceeds the permissible limit established as a reference by the USEPA (1 μg/g). THg concentrations in macrophytes (Eichhornia crassipes) and rice crop plants were higher in sampling stations that receive water currents that carry contaminating loads from mining areas, a similar trend presented for sediments and fish. Conclusions. Mining activities have generated a process of gradual contamination by Hg in the food chain and currently levels in fish, rice and hair represent a serious concern for human health.

GEOGRAPHY, ENVIRONMENT, SUSTAINABILITY, 2019

Mercury is a widespread environmental pollutant becoming a crucial health concern as a result of natural and anthropogenic releases. Understanding Hg distribution pattern between different functional urban areas is needed for urban pollution control and health impact assessment. Therefore, in this paper urban soil Hg spatial distribution, pollution level evaluation, and mercury-induced health risks were studied, for different urban functional areas (355 samples) and kindergartens (18 samples) of Vanadzor. Geospatial mapping and the geostatistical analysis suggest that Hg concentration in the entire area of Vanadzor and its kindergartens has a natural origin, besides a certain anthropogenic impact on some urban sites. According to geoaccumulation index (Igeo), uncontaminated or moderately contaminated levels were detected only in 2 samples from industrial area and 5 samples from residential area, the remaining samples were classified as uncontaminated. In all kindergartens and the 22.15 sq.km of the city (270 samples) are characterized by low level potential ecological risk, whereas 3.85 sq.km (85 samples) correspond to moderate and for 1 sampling site high level of potential ecological risk. A non-carcinogenic health risk assessed for children and adults indicates health hazards neither in Vanadzor entire areas nor in kindergartens. The hazard index (HI) in each urban functional area is less than allowable level (HI <1) for children and adults. Obtained results are indicative and offer the ability for better management of urban soil and urban planning in terms of Hg pollution regulation in different functional areas.

Water, Air, and Soil Pollution, 1995

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