Environmental and biological monitoring of organochlorine pesticides in the city of Salamanca, Mexico.

The former Tekchem Industrial Unit located in the city of Salamanca, Mexico, constitutes an environmental liability in which the presence of high levels of organochlorine pesticides (OCPs) has been reported. In the present study, levels of OCPs were quantified using gas chromatography-mass spectrometry in 52 soil samples and in 88 blood samples from school-age children in the city of Salamanca. A median concentration of 70.6 ng/g (6.93-3299) was obtained for total OCPs in soil, while for the total sum of dichlorodiphenyltrichloroethane (DDT) the value was 49.6 ng/g (6.93-3276). In children, the median level of the total sum of OCPs was 390 ng/g lipid (7.34-14,895), and for the total sum of DDT was 175 ng/g lipid (< LOD-14,802). The OCPs that resulted in highest concentrations in soil were DDT and its metabolites, as well as aldrin and heptachlor epoxide, while in blood the highest levels corresponded to 4,4'-dichlorodiphenyltrichloroethane (4,4'-DDT) and its metabolites, followed by heptachlor and heptachlor epoxide. The spatial distribution of the concentrations of OCPs in soil shows that the facilities of Tekchem may be a significant potential source for the dispersion of these compounds toward the metropolitan area of Salamanca. The results obtained in the present study demonstrate the presence of OCPs in soil and in child population, providing important bases to study the problem from a broader perspective, while reiterating the importance of continuing efforts to generate resolute and precautionary measures with respect to the environmental liability of Tekchem.

Effect of a Supplementation with Two Quelites on Urinary Excretion of Arsenic in Adolescents Exposed to Water Contaminated with the Metalloid in a Community in the State of Guanajuato, Mexico.

Quelites are Mexican wild plants, reported as excellent sources of nutritional compounds such as amino acids (serine, glycine, and cysteine), minerals (Mg, Fe, and Zn), and phytochemicals, as phenolic acids (chlorogenic acid) and flavonoids (phloridzin and naringenin); on the other hand, high biological activity has been shown in these compounds. This work aimed to evaluate the effect of a supplementation with two endemic quelites of Mexico (Chenopodium berlandieri L. and Portulaca Oleracea L.); in addition to supplementation, a nutritional intervention was performed; the biomarkers of hemoglobin (Hb), urinary malondialdehyde (UMDA), and urinary arsenic (UAs) were measured in adolescents exposed to arsenic. A clinical intervention study was conducted in 27 adolescents ages 11 to 12 years for 4 weeks. Weekly anthropometric and dietary evaluations were carried out, as well as the concentration of Hb; the UMDA and UAs were performed by plate-based colorimetric measurement and atomic absorption spectrophotometry with the hydrides generation system, respectively. The results showed that UMDA concentrations had a significant improvement in the supplemented group (SG) vs. control group (CG) (SG = 1.59 ± 0.89 µM/g creatinine vs. CG = 2.90 ± 0.56 µM/g creatinine) in the second week of intervention; on the other hand, the supplemented group showed an increase in Hb levels (15.12 ± 0.99 g/dL) in the same week; finally after the second week, an increase in UAs levels was observed significantly compared to the baseline value (Baseline: 56.85; Week 2: 2.02 µg/g creatinine). Therefore, the results show that the mixture of quelites (a rich source of phytochemicals and nutrients) improved hemoglobin and UMDA levels, and urinary arsenic excretion from the second week in the exposed population.

Parameters of lung inflammation in asthmatic as compared to healthy children in a contaminated city.

BACKGROUND: The impact of air pollution on the respiratory system has been estimated on the basis of respiratory symptoms and lung function. However; few studies have compared lung inflammation in healthy and asthmatics children exposed to high levels of air pollution. The aim of the study was to elucidate the modulatory effect of air pollution on Cysteinyl-leukotrienes (Cys-LTs) levels in exhaled breath condensate (EBC) among healthy and asthmatic children. METHODS: We performed a cross-sectional comparative study. Children between 7-12 years of age, asthmatics and non-asthmatics, residents of a city with high levels of PM10 were included. In all cases, forced spirometry, Cys-LTs levels in EBC, and the International Study of Asthma and Allergies in Childhood questionnaire were evaluated. We also obtained average of PM10, CO, SO2 and O3 levels during the period of the study by the State Institute of Ecology. RESULTS: We studied 103 children (51 asthmatics and 52 non-asthmatics). Cys-LTs levels were higher in asthmatics than in non-asthmatics (77.3 ± 21.6 versus 60.3 ± 26.8 pg/ml; p = 0.0005). Also, Cys-LTs levels in children with intermittent asthma were lower than in children with persistent asthma (60.4 ± 20.4 versus 84.7 ± 19.2 pg/ml; p = 0.0001). In the multiple regression model, factors associated with levels of Cys-LTs were passive smoking (ß = 13.1, p 0.04) and to be asthmatic (ß = 11.5, p 0.03). CONCLUSIONS: Cys-LTs levels are higher in asthmatic children than in healthy children in a contaminated city and its levels are also associated with passive smoking.

Decreased intelligence in children and exposure to fluoride and arsenic in drinking water

Recent evidence suggests that fluoride (F) and arsenic (As) may adversely affect intelligence quotient (IQ) scores. We explore the association between exposure to F and As in drinking water and intelligence in children. Three rural communities in Mexico with contrasting levels of F and As in drinking water were studied: Moctezuma (F 0.8±1.4mg/L; As 5.8±1.3µg/L); Salitral (F 5.3±0.9mg/L; As 169±0.9µg/L) and 5 de Febrero (F 9.4±0.9mg/L; As 194±1.3µg/L). The final study sample consisted of 132 children from 6 to 10 years old. After controlling for confounders, an inverse association was observed between F in urine and Performance, Verbal, and Full IQ scores (beta values = -13, -15.6, -16.9, respectively). Similar results were observed for F in drinking water (beta values = -6.7, -11.2, -10.2, respectively) and As in drinking water (beta values= -4.30, -6.40, -6.15, respectively). The p-values for all cases were < 0.001. A significant association was observed between As in urine and Full IQ scores (beta = -5.72, p = 0.003). These data suggest that children exposed to either F or As have increased risks of reduced IQ scores.

Estudios recientes sugieren que el flúor (F) y el arsénico (As) pueden tener efectos adversos sobre el coeficiente intelectual (CI). En este estudio exploramos la asociación entre el F y el As y la inteligencia en niños expuestos a estas sustancias a través del agua. Tres comunidades rurales de México con diferentes niveles de F y As fueron estudiadas: Moctezuma (F 0,8±1,4mg/L; As 5,8±1,3µg/L); Salitral (F 5,3±0,9mg/L; As 169±0,9µg/L) y 5 de Febrero (F 9,4±0,9mg/L; As 194±1,3µg/L). La muestra final fue de 132 niños de 6 a 10 años de edad. Después de controlar por confusores, se obtuvieron asociaciones inversas entre F en orina y las puntuaciones de los CI (Desempeño, Verbal y Total) (valores beta = -13, -15,6, -16,9, respectivamente) p < 0,001 en todos los casos. Resultados similares se obtuvieron con F en agua (valores beta = -6,7, -11,2, -10,2, respectivamente) y con As en agua (valores beta = -4,30, -6,40, -6,15, respectivamente). En todos los casos p < 0,001. Para As en orina, se obtuvo una asociación inversa con las puntuaciones del CI total (beta= -5,72; p = 0,003). Estos datos sugieren que los niños expuestos al F o al As tienen mayor riesgo de tener disminución en las puntuaciones del CI.