Arsenic and mercury exposure in different insect trophic guilds from mercury mining areas in Mexico.

The exposure to arsenic and mercury in various insect trophic guilds from two mercury mining sites in Mexico was assessed. The two study sites were La Laja (LL) and La Soledad (LS) mines. Additionally, a reference site (LSR) was evaluated for LS. The terrestrial ecosystem was studied at LL, whereas both the terrestrial ecosystem and a stream called El Cedral (EC) were assessed at LS. The study sites are situated in the Biosphere Reserve Sierra Gorda (BRSG). Mercury vapor concentrations were measured with a portable analyzer, and concentrations of arsenic and mercury in environmental and biological samples were determined through atomic absorption spectrophotometry. Both pollutants were detected in all terrestrial ecosystem components (soil, air, leaves, flowers, and insects) from the two mines. The insect trophic guilds exposed included pollinivores, rhizophages, predators, coprophages, and necrophages. In LS, insects accumulated arsenic at levels 29 to 80 times higher than those found in specimens from LSR, and 10 to 46 times higher than those from LL. Similarly, mercury exposure in LS was 13 to 62 times higher than LSR, and 15 to 54 times higher than in LL. The analysis of insect exposure routes indicated potential exposure through air, soil, leaves, flowers, animal prey, carrion, and excrement. Water and sediment from EC exhibited high levels of arsenic and mercury compared to reference values, and predatory aquatic insects were exposed to both pollutants. In conclusion, insects from mercury mining sites in the BRSG are at risk.

Pilot Monitoring of Lead in Umbilical Cord Blood of Newborns Associated With the Use of Glazed Ceramics from Guanajuato, Mexico.

The use of lead-glazed pottery for cooking and storing food, a widespread practice in Mexico, represents a risk of exposure to lead from the human intrauterine stage. Therefore, a pilot study was carried out by means of the measurement of lead in umbilical cord blood by inductively coupled plasma mass spectrometry (ICP-MS) including 69 newborns from the Mexican state capital of Guanajuato, Guanajuato City, where the use of glazed clay is still widespread. Lifestyle and sociodemographic data were collected by interviewing the participating mothers. Hematological parameters and the anthropometry of the newborns and their mothers were analyzed; likewise, the G177C polymorphism in the ALAD gene was genotyped by PCR-RFLP as a marker of genetic vulnerability to lead. The geometric mean of lead in umbilical cord blood was 0.7 µg/dL (< limit of detection = 0.01-28.22). Boys presented higher values than girls (p = 0.03). Only 5.8% of these were above the safety value of the US Centers for Disease Control and Prevention (CDC) of 3.5 µg/dL. Correlations among lead concentrations, maternal age, weeks of gestation, newborn anthropometry, and hematological parameters were not found; however, the participating mothers who reported using glazed ceramics for cooking or storing food had the highest cord-blood lead concentrations (p = 0.04). Regarding genotyping, 97% had ALAD 1, while 3% had ALAD 1, 2; unfortunately, the sample size did not allow analysis of genetic vulnerability to lead. The preparation and conservation of food in handcrafted clay pottery increased the risk of having cord-blood lead values higher than those recommended by the CDC of 3.5 µg/dL (OR = 5; 95% CI:1.3-23; p = 0.01). Our preliminary results suggest that there continues to be intrauterine exposure to lead in Guanajuato.

Holistic health risk assessment in an artisanal mercury mining region in Mexico.

Mexico is one of the world's leading mercury producers and exporters. However, mercury mining is carried out using artisanal procedures, which highly impact ecosystems. In the municipality of Pinal de Amoles, Queretaro, Mexico, artisanal mercury mining (AMM) is practiced in a region that has been categorized as a Biosphere Reserve. Therefore, a holistic health risk assessment for mercury was performed in the region, including environmental monitoring (air, water, and soil) and mercury exposure in both humans (children, women, and miners) and biota (plants, rodents, and worms). The atmospheric mercury determination was carried out using the JEROME® J405 analyzer, whereas total mercury in environmental and biological samples was determined by atomic absorption spectrophotometry/cold vapor. Results showed that mercury concentrations in the environmental and biological matrices exceeded their respective reference values. These results demonstrate the direct influence of AMM in the increasing levels of mercury in all the components of the studied ecosystem. Therefore, comprehensive intervention strategies must be implemented to reduce and prevent human health and ecological risks due to the presence of mercury. In this regard, the Minamata Convention for mercury control should include biomonitoring programs not only for humans but also for critical ecological receptors in polluted ecosystems.

Lead (Pb) exposure is associated with changes in the expression levels of circulating miRNAS (miR-155, miR-126) in Mexican women.

The environmental contamination with lead (Pb) is considered a critical issue worldwide. Therefore, this study aimed to evaluate the expression levels of circulating miRNAs (miR-155, miR-126, and miR-145) in Mexican women exposed to Pb. Blood lead levels (BLL) were assessed in enrolled women (n = 190) using an atomic absorption method. Also, serum miRNAs expression levels were quantified through a real-time PCR assay. A mean BLL of 10.5 ± 4.50 µg/dL was detected. Overexpression of miR-155 was detected in highly exposed women. Besides, a significant simple positive relationship (p < 0.05) was found between BLL and serum miR-155 expression levels. Additionally, a significant inverse correlation (p < 0.05) was determined between BLL and serum miR-126 expression levels, as downregulation of miR-126 expression levels was observed in highly exposed women. The findings in this study are the concern, as epigenetic changes detected may represent a connection between health illnesses and Pb exposure.

Effect of gene-environment interaction (arsenic exposure - PON1 Q192R polymorphism) on cardiovascular disease biomarkers in Mexican population.

Cardiovascular diseases (CVDs) are the primary cause of death worldwide. However, little is known about how the interaction between risk factors affects CVDs. Therefore, the aim of this study was to evaluate the effect of the gene-environment interaction (arsenic exposure x PON1 Q192R polymorphism) on serum levels of CVDs biomarkers in Mexican women. Urinary arsenic levels (UAs) ranged from 5.50-145 µg/g creatinine. The allele frequency was 0.38 and 0.62 for the Q and R alleles, respectively. Moreover, significant associations (p<0.05) were detected between UAs and CVDs biomarkers (ADMA, FABP4, and miR-155). Comparable data were found when CVDs biomarkers were evaluated through PON1 genotype, significant (p<0.05) higher serum concentrations of CVDs biomarkers were identified in R allele carriers compared to levels found in Q allele carriers. Besides, a gene-environment interaction was documented. The results of this study we believe should be of significant interest to regulatory authorities worldwide.

Circulating miRNA-126, -145 and -155 levels in Mexican women exposed to inorganic arsenic via drinking water.

The aim of this research was to investigate circulating expression levels of three miRNAs (miR-126, miR-155, and miR-145) proposed as predictive CVD biomarkers in Mexican women exposed to inorganic arsenic via drinking water. Mean UAs concentration of 19.5 ± 14.0 µg/g creatinine was found after urine samples were analyzed (n = 105). Significant associations between UAs levels and serum expression levels of miR-155 (p < 0.05) and miR-126 (p < 0.05) were observed after adjustment for assessed co-variables. Alterations in the serum expression levels of miR-155 and miR-126 may be associated with the onset and development of cardiovascular diseases, hence miRNAs could be proposed as prognostic CVD biomarkers. Data found in this study are of concern and risk reduction plans are necessary for the assessed communities to prevent cardiovascular events in this population of women.

Impact of arsenic exposure on clinical biomarkers indicative of cardiovascular disease risk in Mexican women.

An appropriate and precise identification of high-risk individuals to develop cardiovascular diseases (CVD) is of high importance to reduce these kinds of diseases, a major health concern worldwide. Therefore, the aim of this research was to evaluate prognostic CVD biomarkers in Mexican women exposed to inorganic arsenic via drinking water. Then, a cross-sectional study including 190 women was achieved. Urinary arsenic (UAs) levels were analyzed as exposure biomarker to that metalloid. While, plasma asymmetric dimethylarginine (ADMA), adipocyte fatty acid-binding protein (FABP4), adiponectin, and chemerin levels, hypertriglyceridemic waist (HW) phenotype, atherogenic index of plasma (AIP), and Framingham risk score (FRS) were assessed as prognostic CVD biomarkers. Mean UAs level detected in the evaluated urinary samples was 45.0 ±â€¯40.0 µg/g creatinine. In addition, mean plasma ADMA, FABP4, chemerin and adiponectin levels were 0.68 µmol/L, 20.3 ng/mL, 12.5 µg/mL, and 255 ng/mL, correspondingly. Approximately, 54% of women participants displayed an HW phenotype. Regarding AIP and FRS values, 0.12 ±â€¯0.15 and 7.50 ±â€¯8.00 were found, respectively. Besides, strong and significant associations (p < 0.05) between UAs and AIP, ADMA, and FABP4 were distinguished. Also, after a multivariate analysis, the association between those variables persisted after adjustment for traditional risk factors of CVD. In conclusion, according to the results found in this research, the most sensible CVD biomarkers distinguished in this study were AIP, ADMA, and FABP4. Nevertheless, more studies are necessary to confirm the results found in this investigation.

[Effect of a four-week vitamin and mineral supplementation on the nutritional status and urinary excretion of arsenic in adolescents]. / Efecto de una suplementación de vitaminas y minerales de cuatro semanas sobre el estado nutricio y excreción urinaria de arsénico en adolescentes.

INTRODUCTION: adequate nutrition in adolescence is important for growth and development. There are environmental factors that cannot be avoided, such as exposure to heavy metals through natural sources such as water. Arsenic is a metalloid that can cause damage to health (alterations in nutritional status, diabetes, cancer) and it has been found in concentrations higher than those allowed in drinking water. OBJECTIVE: to measure the effect of vitamin and mineral supplementation on the nutritional status and urinary excretion of arsenic in adolescents exposed to this metal through drinking water. MATERIAL AND METHODS: an observational, follow-up study of a cohort was conducted to assess the efficacy of vitamin and mineral supplementation on supplementation in 45 adolescents exposed to arsenic in drinking water, who were given a daily multivitamin supplement for four weeks. Weekly nutritional status and arsenic levels in urine and drinking water were evaluated. RESULTS: the basal nutritional intake was low for proteins, fiber, folic acid, vitamin B2, B6, B12, E, C, selenium and iron, increasing their consumption through the supplement during the intervention and with an increase of approximately 1 g/dl of hemoglobin in all participants. At the end of the intervention, there was an increase in fat-free mass and a decrease in the percentage of body fat. In relation to the urinary excretion of arsenic, the biggest elimination of this metalloid was observed from the first week of intervention (35.91 µg/g Cr [IC 95% = 23.2-74.8 µg/g Cr]), which was statistically significant compared to basal levels of urinary arsenic (43.2 µg/g Cr [IC 95% = 30.8-117.6 µg/g Cr]) (p < 0.05), with an average water consumption with As of 96.2 ± 7.5 µg/l. CONCLUSION: four weeks of supplementation with vitamins and minerals in the adolescent population studied improved nutritional status and increased metalloid excretion significantly in the first and second week after intervention.

Introducción: la adecuada nutrición en la adolescencia es de importancia para el crecimiento y desarrollo. Existen factores ambientales que no pueden evitarse, como la exposición a metales pesados a través de fuentes naturales como el agua. El arsénico es un metaloide que puede causar un daño a la salud (alteraciones del estado nutricio, diabetes, cáncer) y ha sido encontrado en concentraciones superiores a las permitidas en el agua de consumo.Objetivo: medir el efecto de una suplementación de vitaminas y minerales sobre el estado nutricio y la excreción urinaria de arsénico en adolescentes expuestos a este metal a través de agua de consumo.Material y métodos: se realizó un estudio de intervención y longitudinal para la valorar la eficacia de la suplementación de vitaminas y minerales sobre la suplementación en 45 adolescentes, expuestos a arsénico en agua de consumo, a quienes se dio un suplemento multivitamínico diariamente durante cuatro semanas. De forma semanal se evaluaron el estado nutricio y los niveles de arsénico en orina y en agua de consumo.Resultados: en la población de estudio se observó que el consumo nutrimental basal fue bajo para proteínas, fibra, ácido fólico, vitamina B2, B6, B12, E, C, selenio y hierro, incrementando su consumo a través del suplemento durante la intervención y con un aumento de aproximadamente 1 g/dl de hemoglobina en todos los participantes. Al final de la intervención presentaron incremento de masa libre de grasa y disminución en el porcentaje de grasa corporal. Por otro lado, en cuanto a la excreción urinaria de arsénico, se observó mayor eliminación de este metal (35,91 µg/g Cr [IC 95% = 23,2-74,8 µg/g Cr]) desde la primera semana de intervención, la cual fue estadísticamente significativa en comparación con los niveles basales de arsénico urinario (43,2 µg/g Cr [IC 95% = 30,8-117,6 µg/g Cr]) (p < 0,05), con un consumo promedio de agua con As de 96,2 ± 7,5 µg/l.Conclusión: la suplementación con vitaminas y minerales de cuatro semanas en la población de adolescentes estudiada mejoró el estado nutricio y aumentó la excreción del metaloide de manera significativa en la primera y segunda semana postintervención.

Efecto de una suplementación de vitaminas y minerales de cuatro semanas sobre el estado nutricio y excreción urinaria de arsénico en adolescentes / Effect of a four-week vitamin and mineral supplementation on the nutritional status and urinary excretion of arsenic in adolescents

Introducción: la adecuada nutrición en la adolescencia es de importancia para el crecimiento y desarrollo. Existen factores ambientales que no pueden evitarse, como la exposición a metales pesados a través de fuentes naturales como el agua. El arsénico es un metaloide que puede causar un daño a la salud (alteraciones del estado nutricio, diabetes, cáncer) y ha sido encontrado en concentraciones superiores a las permitidas en el agua de consumo. Objetivo: medir el efecto de una suplementación de vitaminas y minerales sobre el estado nutricio y la excreción urinaria de arsénico en adolescentes expuestos a este metal a través de agua de consumo. Material y métodos: se realizó un estudio de intervención y longitudinal para la valorar la eficacia de la suplementación de vitaminas y minerales sobre la suplementación en 45 adolescentes, expuestos a arsénico en agua de consumo, a quienes se dio un suplemento multivitamínico diariamente durante cuatro semanas. De forma semanal se evaluaron el estado nutricio y los niveles de arsénico en orina y en agua de consumo. Resultados: en la población de estudio se observó que el consumo nutrimental basal fue bajo para proteínas, fibra, ácido fólico, vitamina B2, B6, B12, E, C, selenio y hierro, incrementando su consumo a través del suplemento durante la intervención y con un aumento de aproximadamente 1 g/dl de hemoglobina en todos los participantes. Al final de la intervención presentaron incremento de masa libre de grasa y disminución en el porcentaje de grasa corporal. Por otro lado, en cuanto a la excreción urinaria de arsénico, se observó mayor eliminación de este metal (35,91 μg/g Cr [IC 95% = 23,2-74,8 μg/g Cr]) desde la primera semana de intervención, la cual fue estadísticamente significativa en comparación con los niveles basales de arsénico urinario (43,2 μg/g Cr [IC 95% = 30,8-117,6 μg/g Cr]) (p < 0,05), con un consumo promedio de agua con As de 96,2 ± 7,5 μg/l. Conclusión: la suplementación con vitaminas y minerales de cuatro semanas en la población de adolescentes estudiada mejoró el estado nutricio y aumentó la excreción del metaloide de manera significativa en la primera y segunda semana postintervención

Introduction: adequate nutrition in adolescence is important for growth and development. There are environmental factors that cannot be avoided, such as exposure to heavy metals through natural sources such as water. Arsenic is a metalloid that can cause damage to health (alterations in nutritional status, diabetes, cancer) and it has been found in concentrations higher than those allowed in drinking water. Objective: to measure the effect of vitamin and mineral supplementation on the nutritional status and urinary excretion of arsenic in adolescents exposed to this metal through drinking water. Material and methods: an observational, follow-up study of a cohort was conducted to assess the efficacy of vitamin and mineral supplementation on supplementation in 45 adolescents exposed to arsenic in drinking water, who were given a daily multivitamin supplement for four weeks. Weekly nutritional status and arsenic levels in urine and drinking water were evaluated. Results: the basal nutritional intake was low for proteins, fiber, folic acid, vitamin B2, B6, B12, E, C, selenium and iron, increasing their consumption through the supplement during the intervention and with an increase of approximately 1 g/dl of hemoglobin in all participants. At the end of the intervention, there was an increase in fat-free mass and a decrease in the percentage of body fat. In relation to the urinary excretion of arsenic, the biggest elimination of this metalloid was observed from the first week of intervention (35.91 μg/g Cr [IC 95% = 23.2-74.8 μg/g Cr]), which was statistically significant compared to basal levels of urinary arsenic (43.2 μg/g Cr [IC 95% = 30.8-117.6 μg/g Cr]) (p < 0.05), with an average water consumption with As of 96.2 ± 7.5 μg/l. Conclusion: four weeks of supplementation with vitamins and minerals in the adolescent population studied improved nutritional status and increased metalloid excretion significantly in the first and second week after intervention

Exposure to Mixtures of Pollutants in Mexican Children from Marginalized Urban Areas.

BACKGROUND: Exposure to contaminant mixtures in developing countries is an important public health issue. Children are identified as the most susceptible group to adverse health effects due to the exposure. OBJECTIVE: The aim of this study was to conduct a screening for mixture pollutants in Mexican children in urban marginalized communities. METHODS: We analyzed children (aged 6-12 years old) who resided in four urban marginalized communities in San Luis Potosi, Mexico: i) Bellas Lomas (BEL), a site with vehicular traffic; ii) Tercera Chica (TC), a site with brick kilns; Iii) Rincon de San Jose (SJR), a site with a hazardous waste landfill; and (iv) Morales (MOR) a metallurgical zone with copper-arsenic and electrolytic zinc smelters. Polycyclic Aromatic Hydrocarbons (1-hydroxypyrene (1-OHP)), benzene (trans, trans-muconic acid (t,t-MA), manganese, arsenic and fluoride were quantified in urine and lead in blood samples. FINDINGS: Our results indicate that median exposures to manganese were 4.4, 5.2, 5.8 and 6.3 µg/L for BEL, TC, SJR and MOR, respectively. For BEL, fluoride was present at a higher concentration with 2.3 mg/L followed by MOR, TC and SJR with 1.7, 1.5 and 1.2 mg/L respectively. The highest concentrations of arsenic that were found were 11 µg/L in MOR and lead concentration was reported between 4.2 and 6.8 µg/dL, in BEL, TC and MOR. 1-OHP and t,t-MA were higher in TC (0.23 µmol/mol creatinine (cr), 429.7 µg/g cr, respectively) followed by SJR (0.09 µmol/mol cr, 427.4 µg/g cr), MOR (0.03 µmol/mol cr, 258.6 µg/g cr) and BEL (0.06 µmol/mol cr, 220.6 µg/g cr). CONCLUSION: Considering the large number of people, especially children, exposed to multiple pollutants, it is important to design effective intervention programs that reduce exposure and the resultant risk in the numerous urban marginalized communities in Mexico.

Serum Concentrations of New Predictive Cardiovascular Disease Biomarkers in Mexican Women Exposed to Lead.

The purpose of this study was to evaluate lead exposure and its relationship with serum levels of predictive CVD biomarkers [asymmetric dimethylarginine (ADMA), adipocyte fatty acid-binding protein (FABP4), adiponectin, and chemerin] in women living in San Luis Potosi, Mexico. A mean blood lead level (BLL) of 11.5 ± 9.00 µg/dL (mean ± standard deviation) was found after all blood samples were analyzed. Regarding serum predictive CVD biomarkers, mean serum level of 0.68 ± 0.38 µmol/L, 20.5 ± 16.5 ng/mL, 12.5 ± 3.30 µg/mL, and 255 ± 130 ng/mL were found for ADMA, FABP4, adiponectin, and chemerin, respectively. Simple significant associations (Pearson´s correlations) between BLL and ADMA (r = 0.17; p = 0.04) and FABP4 (r = 0.23; p = 0.03) were found. Furthermore, a multivariate linear regression model showed that BLL was a significant predictor of serum ADMA (ß = 0.06; p = 0.001) and FABP4 (ß = 1.75; p = 0.0004) concentrations after adjusting by confounders. For serum chemerin and adiponectin levels, no associations were found with BLL. In conclusion, high serum ADMA and FABP4 (predictive CVD biomarkers) levels were found in women exposed to lead. Consequently, this research can be used as a point of departure for the prevention of CVD events in populations living in sites environmentally impacted with lead.

DNA methylation changes in Mexican children exposed to arsenic from two historic mining areas in San Luis potosí.

Arsenic is a carcinogen and epimutagen that threatens the health of exposed populations worldwide. In this study, we examined the methylation status of Alu and long interspersed nucleotide elements (LINE-1) and their association with levels of urinary arsenic in 84 Mexican children between 6 and 12 years old from two historic mining areas in the State of San Luis Potosí, Mexico. Urinary arsenic levels were determined by atomic absorption spectrophotometry and DNA methylation analysis was performed in peripheral blood leukocytes by bisulfite-pyrosequencing. The geometric mean of urinary arsenic was 26.44 µg/g Cr (range 1.93-139.35). No significant differences in urinary arsenic or methylation patterns due to gender were observed. A positive correlation was found between urinary arsenic and the mean percentage of methylated cytosines in Alu sequences (Spearman correlation coefficient r = 0.532, P < 0.001), and a trend of LINE-1 hypomethylation was also observed (Spearman correlation coefficient r = -0.232, P = 0.038) after adjustment for sex and age. A linear regression model showed an association with log-normalized urinary arsenic for Alu (ß = 1.05, 95% CI: 0.67; 1.43, P < 0.001) and LINE-1 (ß = -0.703, 95% CI: -1.36; -0.38, P = 0.038). Despite the low-level arsenic exposure, a subtle epigenetic imbalance measured as DNA methylation was detected in the leukocytes of Mexican children living in two historic mining areas. Environ. Mol. Mutagen. 57:717-723, 2016. © 2016 Wiley Periodicals, Inc.

Exposure Assessment to Environmental Chemicals in Children from Ciudad Juarez, Chihuahua, Mexico.

It has been demonstrated that the human biomonitoring of susceptible populations is a valuable method for the identification of critical contaminants. Therefore, the purpose of this study was to assess the exposure profile for arsenic (As), lead (Pb), mercury (Hg), 1-hydroxypyrene (1-OHP), 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) in children living in Ciudad Juarez, Chihuahua, Mexico (a major manufacturing center in Mexico). In 2012, we evaluated a total of 135 healthy children living in Ciudad Juarez since birth. The total PBDEs levels ranged from nondetectable (< LOD) to 215 ng/g lipid, with a mean total PBDEs level of 29.5 ± 53.0 ng/g lipid (geometric mean ± standard deviation). The mean total PCBs level in the study participants was 29.0 ± 10.5 ng/g lipid (range 4.50-50.0 ng/g lipid). The mean concentration of total DDT (DDT + DDE) was 11.9 ± 6.70 ng/g lipid (range 3.00-26.0 ng/g lipid). The mean 1-OHP levels was 1.2 ± 1.1 µmol/mol creatinine (range

Lead in school children from Morelos, Mexico: levels, sources and feasible interventions.

BACKGROUND: Lead is a pervasive pollutant, associated at low levels to many adverse health effects. OBJECTIVE: To investigate lead levels, exposure pathways and intervention possibilities in school children from Alpuyeca, in Morelos, Mexico. METHODS: Blood lead concentrations (BPb) were measured in 226 children in 2011. Exposure pathways were assessed through a questionnaire, lead measurements in different environmental matrices and spatial aggregation analysis of lead concentrations. RESULTS: BPb ranged from 1.5 to 36.5 ìg/dL, with a mean (SD) of 7.23 (4.9) ìg/dL. Sixty-four and 18% of the children had BPb > 5 ìg/dL and > 10 ìg/dL, respectively. The use of lead glazed ceramics was reported in almost half of the households; it was the main BPb determinant and it was associated with an increased risk of having BPb > 5 g/dL by 2.7 times (p = 0.001). Environmental samples were within US EPA's lead recommended limits, and blood lead levels were randomly distributed in the community. CONCLUSIONS: Lead remains a public health problem in Alpuyeca, Mexico. Unlike other local pollutant lead exposure prevention can be achieved inexpensively and in a short term. Interventions should make mothers aware of lead's health effects and empower them to safeguard their children's health by avoiding the culturally ingrained use of lead glazed pottery.

Genotoxic and hematological effects in children exposed to a chemical mixture in a petrochemical area in Mexico.

Children living in Coatzacoalcos, Veracruz, and in nearby surrounding areas are exposed to a mixture of pollutants from different sources. Previous studies in the area have reported genotoxic and haematotoxic compounds, such as lead (Pb), benzene, toluene, and polycyclic aromatic hydrocarbons (PAHs), in environmental and biological samples. The final toxic effects of these compounds are unknown because the toxic behaviour of each compound is modified when in a complex mixture. This is the first study on the exposure and effect of chemical mixtures on children who live near a petrochemical area. The aim of this study was to evaluate genotoxicity and haematological effects in children environmentally exposed to such mixtures and to determine whether the final effect was modified by the composition of the mixture composition. Biomarkers of exposure to Pb, benzene, toluene, and PAHs were quantified in urine and blood samples of 102 children. DNA damage was evaluated using comet assay, and haematological parameters were determined. Our results show that Pb and toluene did not surpass the exposure guidelines; the exposure was similar in all three localities (Allenede, Mundo Nuevo, and López Mateos). In contrast, exposure to PAHs was observed at three levels of exposure: low, medium, and high. The most severe effects of these mixtures were strictly related to coexposure to high levels of PAHs.

Epigenetic markers of exposure to polycyclic aromatic hydrocarbons in Mexican brickmakers: a pilot study.

A pilot cross-sectional study was carried out in a group of 39 male brick manufacturers in San Luis Potosi, Mexico to identify epigenetic biomarkers of exposure to polycyclic aromatic hydrocarbons (PAHs). A questionnaire was used to compile the smoking and drinking habits, clinical history, working time, and socioeconomic characteristics of the participants. 1-Hydroxypyrene (1-OHP) levels were measured from urine samples using high-performance liquid chromatography, and genomic DNA was isolated from blood samples for methylation analysis using pyrosequencing. The mean 1-OHP level was 0.18 µg g(-1) creatinine (range 0.023-1.11), which was below the expected occupational exposure level. After adjusting for potential confounders, the 1-OHP urine concentration was negatively associated with DNA methylation of the interleukin 12 (ß=-1.57; 95% CI: -2.9 to -0.23; p=0.02) and p53 gene promoters (ß=-2.7; 95% CI: -5.46-0.06; p=0.055). Suggestive negative associations were also found for the TNF-α gene (ß=-3.9; 95% CI:-8.28-0.48; p=0.08) and Alu sequences (ß=-0.55; 95% CI:-1.25-0.16; p=0.12). Although the individual exposures to PAHs as estimated by urinary 1-OHP concentrations were low, changes in specific and global DNA methylation were observed.

[Designing and application of a Risk Communication Program for children environmental health on a lead and arsenic contaminated location]. / Diseño y aplicación de un Programa de Comunicación de Riesgos para la salud ambiental infantil en un sitio contaminado con plomo y arsénico.

A metallurgical industry in San Luis Potosí city, México, has contaminated the zone by lead (Pb) and arsenic (As). Since 1989 were reported by our group high concentrations of Pb in blood (PbB) and As in urine (AsU) in the local children. In present work, a Risk Communication Program (RCP) was generated to inform the children about the environmental risks of the site where they live, and to change conducts to diminish the exposure to Pb and As. We worked with 170 children (5 to 7 years) of the zone. The RCP was applied and the evaluation was realized by means of analysis of drawings, questionnaires and biological monitoring. In drawings of the children appeared toxic elements such as Pb, contaminated soil, cigarettes, among others. In the questionnaires applied to the children and family parents it was possible to estimate a change in the knowledge and in some conducts with regard to the pollutants, their effects and their exposure. There was not a decrease in the levels of PbB and in the levels of AsU. These were due probably because the principal route of exposure is not only the soil that had been contemplated previously.

Diseño y aplicación de un Programa de Comunicación de Riesgos para la salud ambiental infantil en un sitio contaminado con plomo y arsénico / Designing and application of a Risk Communication Program for children environmental health on a lead and arsenic contaminated location

Una industria metalúrgica en la ciudad de San Luis Potosí, México ha contaminado el sitio con plomo (Pb) y arsénico (As) principalmente. Desde 1989 se han reportado por nuestro grupo altas concentraciones de Pb en sangre (PbS) y As en orina (AsO) en los niños del lugar. En el presente estudio se generó un Programa de Comunicación Riesgos (PCR) para informar a los niños sobre los riesgos ambientales del sitio donde viven y que cambiaran conductas para disminuir la exposición al Pb y al As. Se trabajó con 170 niños (5 a 7 años) de la zona. Se aplicó el PCR y se realizó la evaluación mediante análisis de dibujos, cuestionarios y monitoreo biológico. En los dibujos de los niños se encontraron elementos tóxicos tales como el Pb, la tierra contaminada, entre otros. En los cuestionarios aplicados a los niños y a los padres de familia se pudo apreciar un cambio en los conocimientos y en algunas conductas respecto a los contaminantes, sus efectos y su exposición. No se encontró una disminución en los niveles de PbS ni de AsO. Esto quizás porque la principal ruta de exposición no es únicamente el suelo, como se había contemplado anteriormente.

A metallurgical industry in San Luis Potosí city, México, has contaminated the zone by lead (Pb) and arsenic (As). Since 1989 were reported by our group high concentrations of Pb in blood (PbB) and As in urine (AsU) in the local children. In present work, a Risk Communication Program (RCP) was generated to inform the children about the environmental risks of the site where they live, and to change conducts to diminish the exposure to Pb and As. We worked with 170 children (5 to 7 years) of the zone. The RCP was applied and the evaluation was realized by means of analysis of drawings, questionnaires and biological monitoring. In drawings of the children appeared toxic elements such as Pb, contaminated soil, cigarettes, among others. In the questionnaires applied to the children and family parents it was possible to estimate a change in the knowledge and in some conducts with regard to the pollutants, their effects and their exposure. There was not a decrease in the levels of PbB and in the levels of AsU. These were due probably because the principal route of exposure is not only the soil that had been contemplated previously.