Water Consumption as Source of Arsenic, Chromium, and Mercury in Children Living in Rural Yucatan, Mexico: Blood and Urine Levels (original) (raw)
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Bulletin of Environmental Contamination and Toxicology, 2018
Merida is the largest urban center in the Mexican State of Yucatan. Here domestic sewage is deposited in poorly built septic tanks and is not adequately treated. Because of contamination from such waste, water from the top 20 m of the aquifer is unsuitable for human consumption. Given this situation and because children are highly vulnerable to environmental pollution, including exposure to toxic trace elements, this study focused on evaluating the exposure of children to arsenic (As), chromium (Cr), and mercury (Hg) in water. It also evaluated the relationship between the levels of these elements in water and their concentrations in urine and blood. Among the 33 children monitored in the study, arsenic surpassed WHO limits for blood in 37% of the cases, which could result from the ingestion of poultry contaminated with organoarsenic compounds. In the case of WHO limits for Mercury, 65% of the water samples analyzed, 28% of urine samples, and 12% of blood samples exceeded them. Mercury exposure was correlated with biological sex, some lifestyle factors, and the zone in Merida in which children live. These data suggest that the levels of some toxic metals in children may be affected by water source, socioeconomic factors, and individual behavior.
2010
The Ria of Huelva (south-west Spain) is a highly polluted estuary as a consequence of long-term mining and industrial activities. Between 2003 and 2004, we conducted a biomonitoring study of exposure to arsenic and some heavy metals (cadmium, chromium, copper and nickel) in urine samples of a representative sample (n = 227) of children and adolescents residing in this area, and of a reference group of 196 children and adolescents living in other less industrialised areas of Andalusia (south Spain). We also assessed the determinants of the variability in urinary metals within the population of the Ria of Huelva. There were no significant differences in the concentration of metal compounds between the two groups with the exception of Cd levels, which were significantly higher in the reference group. Levels of the five metal ions in both groups were generally within the range of values reported by other biomonitoring studies for general children population, although mean Cd levels tended to be higher as compared to other European studies. Among the population of the Ria of Huelva, the main determinants of the interindividual variation in urinary metals were age, sex, area of residence, and frequency of intake of certain food items (mainly fish and shellfish). Overall, results suggest that living in the Ria of Huelva is not increasing current levels of exposure to certain metals among children and adolescents above those found in other urban areas of Andalusia.
An integrated health risk assessment of indigenous children exposed to arsenic in Sonora, Mexico
Human and Ecological Risk Assessment, 2018
Exposure to inorganic arsenic (InAs) through drinking water, even at low to moderate concentrations, is a global public health problem. The objectives of this study were to estimate the risk ratio (HQ), cancer risk (R), and DNA damage (comet assay) of children from three indigenous Yaqui populations located in southern Sonora, Mexico, who were exposed to InAs through drinking water. A cross-sectional study was employed, and analysis of InAs in water and urine was performed via HPLC/ICP-MS. InAs levels in drinking water from P otam, V ıcam, and C ocorit were 108.2, 36.0, and 6.2 mg/L ¡1 respectively. Children from P otam had arsenic concentrations in urine of 107.1 mg As L ¡1 compared with 40.3 mg As L ¡1 for the children of C ocorit. The HQ values for the children of P otam, V ıcam, and C ocorit were 16.64, 6.02, and 0.94, while the R values were 9.4E-04, 3.5E-04, and 5.7E-05, respectively. Children with the highest arsenic exposure had significantly increased DNA damage (OTM = 14.4 vs. 4.3) [p < 0.0005] which positively correlated with urinary arsenic levels (r D 0.56, p < 0.0001). In conclusion, children of P otam and V ıcam are at significant risk of developing chronic diseases and cancers associated with chronic exposure to this metalloid.
Lack of potable water is an important problem of global dimensions. In Mexico, the northern and central regions have significant shortages, a situation which is exacerbated by the pollution of aquifers. Several studies have reported controversial results on high concentrations of heavy metals and halogens in aquifers in the state of Aguascalientes. Poor water quality is caused by the geological conditions in the region, water over-exploitation, and inadequate disposal of industrial waste. However, human exposure to these xenobiotics and their associated toxicological impact has received minimal attention. Many of these contaminants are nephrotoxic agents and this condition is aggravated when they mix.
Arsenic in Mexican Children Exposed to Contaminated Well Water
Ecology of food and …, 2009
This cross-sectional study measures the arsenic level in school children exposed to contaminated well water in a rural area in México. Arsenic was measured in hair by hydride generation atomic absorption spectrophotometry. Overall, 110 children were included (average 10 years-old). Among 55 exposed children, mean arsenic level on hair was 1.3 mg/kg (range <0. 006-5.9). All unexposed children had undetectable arsenic levels. The high level of arsenic in water was associated to the level in hair. However, exposed children drank less well water at school or at home than unexposed children, suggesting that the use of contaminated water to cook beans, broths or soups may be the source of arsenic exposure.
Environmental exposure to lead and mercury in Mexican children: a real health problem
Toxicology Mechanism and Methods, 2011
Exposure to lead (Pb) and mercury (Hg) remains a world public health problem, particularly for young children in developing countries. In Mexico, the main sources of exposure to Pb and Hg are wastes from human activities that increase the natural sources of these metals. Pb and Hg are highly toxic during development and maturation periods of the central nervous system (CNS); these effects are associated with the risk for neurodegenerative diseases. Mexico has numerous exposure sources to Pb and Hg; nevertheless, information on exposure in children is limited, particularly for Hg. Therefore, we conducted a review of the studies performed in children exposed to Pb and Hg. Data presented to support that an important proportion of Mexican children have Pb levels above values associated with dangerous effects. On the other hand, studies on Hg-exposure are scarce, so we need more studies to estimate the magnitude of the problem and to determine exposure levels in Mexican children. Available data support the urgent need for coordinated actions among researchers, and health and environmental government authorities to implement education and nutritional campaigns, as well as to decrease exposure and effects of Pb and Hg. In addition, there must be a priority for the implementation of educational campaigns directed to the general population, but with an emphasis in parents, education staff and health care providers to decrease both the risk of exposure of children to Pb and Hg and the effects of the exposure to these metals.
Trace Elements in Portuguese Children: Urinary Levels and Exposure Predictors
Toxics
Exposure to environmental chemicals during developmental stages can result in several adverse outcomes. In this study, the exposure of Portuguese children to Cu, Co, I, Mo, Mn, Ni, As, Sb, Cd, Pb, Sn and Tl was evaluated through the analysis of first morning urine through ICP-MS. Furthermore, we attempted to determine possible exposure predictors. The study sample consisted of 54% girls and 46% boys, with a median age of 10 years; 61% were overweight/obese and were put on a nutritionally oriented diet. For I, half of the population was probably in deficiency status. The median urinary concentrations (μg/L) were Cu 21.9, Mo 54.6, Co 0.76, Mn 2.1, Ni 4.74, As 37.9, Sb 0.09, Cd 0.29, Pb 0.94, Sn 0.45, Tl 0.39 and I 125.5. The region was a significant predictor for Cu, Co, Ni, As and Tl. Children living in an urban area had higher urinary levels, except for Co and Ni. Age was a significant predictor for Cu, I, Mo, Mn, Ni, Sb, Cd and Sn with urinary levels of these elements decreasing wi...
Pattern of Arsenic exposure to children
Elevated levels of arsenic are found in several countries which exceed the World Health Organization (WHO) drinking water guideline (10µg/L), affecting 100 million people globally. Its prevalence varies in different countries among which Andean Argentina and South-East Asia are most severely affected. Bangladesh is considered a major As-contaminated zone and more than 10µg/L of As is present in the tube wells installed during the last decade. As-contaminated water poses serious threat to the population in general, and children in particular. School-age children exposed to As are found to be deficient in cognitive functions in several countries. Although As contamination is a global phenomenon reports on children's exposure to As, through breast milk pathway is limited. Findings of the few global studies show low level of As in breast milk even in populations exposed to high levels. Several reports indicate the potential counterbalancing the impact of exposures of chemicals through breast milk which outweigh the hazards of feeding contaminated breast milk. On the other hand, the presence of toxic elements in powdered and liquid infant milk is a cause of concern considering the probable health problems in infants. It is surmised from available data that although the lactating mothers resided in highly As-contaminated zones the concentration of the toxic metal is low in the breast milk and breast feeding infants are protected from the toxic effects of As. Therefore breast feeding is still the best way to protect the infants in As-contaminated zones as per WHO recommendations.