Urinary levels of organophosphate pesticides and predictors of exposure in pre-school and school children living in agricultural and urban communities from south Spain.

BACKGROUND: Despite the widespread use of organophosphate (OP) pesticides, information on predictors of children's exposure to such pesticides is scarce. OBJECTIVE: To assess exposure to OP pesticides in children 3-11 year-old living in agricultural communities and urban areas from Andalusia (Southern Spain), and to identify the main determinants of exposure. METHODS: A longitudinal study was conducted in children 3-11-year-old children living in agricultural communities and urban areas from the provinces of Almeria, Granada and Huelva (Andalusia, Spain) between 2010 and 2011. Urinary levels of six dialkylphosphate (DAP) metabolites were measured by UHPLC-QqQ-MS/MS at the periods of low and high pesticide use in the agriculture (LPU and HPU, respectively). Information on sociodemographic characteristics, parental occupation, residential history, lifestyle and diet, among other relevant factors, was obtained from questionnaires administered to the mothers. RESULTS: A total of 559 and 597 children participated in LPU and HPU periods, respectively. The proportion of urine samples below LOD was 67.4% for ΣDMs (sum of dimethyl metabolites), 77% for ΣDEs (sum of diethyl metabolites) and 58.5% for ΣDAPs (sum of total dialkylphosphate metabolites) in LPU period, and 50.4% for ΣDMs, 65.3% for ΣDEs and 43.9% for ΣDAPs in HPU period. Significantly greater urinary ΣDAP, ΣDM and ΣDE levels were observed in HPU relative to LPU period. Maternal schooling years, proximity of the house to crops or greenhouses, use of insecticides at home, spraying the garden with pesticides, storage of pesticides at home, house cleaning frequency, as well as child's frequency of bath/shower, were found to be the major predictors of urinary levels of ΣDAP. Likewise, not washing fruit and vegetables before consumption and banana consumption were also identified as determinants of the exposure levels. CONCLUSIONS: Urinary levels of metabolites of OP pesticides found in this study were relatively lower compared to similar studies. DAP levels were significantly increased in HPU period. Maternal schooling years and variables related to residential environment and home exposures were identified as the most relevant determinants of DAP metabolites. Regarding diet, banana consumption and not washing fruit before consumption were also identified as determinants of the exposure levels. This study contributes to improve our knowledge on the main sources and determinants of children exposure to OPS, and given that children are more vulnerable than adults this information is essential to reduce children exposure and protect their health.

Biomonitoring of 45 inorganic elements measured in plasma from Spanish subjects: A cross-sectional study in Andalusian population.

Heavy metals and other toxic elements are frequently detected in humans. Rare earth elements (REE) have arisen as a novel group of substances considered as emerging pollutants due to its dependence for high tech industry. We designed a study aimed to conduct the biomonitoring a total of 45 inorganic elements in the population of Andalusia (Spain). A total of 419 participants were recruited and their plasma samples analyzed. Concentration of elements, including elements in the ATSDR's priority pollutant list and REE were measured by ICP-MS in the blood plasma of participants. Arsenic, copper, lead, selenium, antimony, strontium, and bismuth were detected in ˃98% of subjects. Median values of arsenic, mercury and lead were 1.49, 1.46, and 5.86 ng/mL, respectively. These concentrations did not exceed reference values published by international agencies. We observed a positive correlation between age and plasma concentrations of arsenic, mercury, antimony and strontium. Sum of elements was lower in the group of subjects younger than 45 years old (P = 0.002). Positive correlations were observed between body mass index (BMI) and plasma concentrations of barium, cerium, osmium, tin, and ytterbium. 7 out of 26 REEs showed a percentage of detection ≥ 90%. Bismuth, yttrium, and cerium were quantified at the highest concentrations (median value = 7.7, 0.19, and 0.16 ng/mL, respectively). We found that plasma levels of 6 REEs were higher among males, and a positive correlation between REEs and age was detected. The present results suggest a potential interaction with the human physiology that deserves additional research. Given the high persistence of these elements in the environment, and the significant technological dependence on them, future studies are needed to elucidate the potential sources of exposure and possible adverse effects on health, especially in the most vulnerable populations.

Serum concentrations of organochlorine compounds and predictors of exposure in children living in agricultural communities from South-Eastern Spain.

BACKGROUND: Information on exposure levels to organochlorine compounds (OCs) in child population is limited, despite their greater vulnerability to the adverse health effects of these chemicals. OBJECTIVE: To determine serum concentrations of 10 OCs (including organochlorine pesticides and polychlorinated biphenyls -PCBs-) in children living in agricultural communities from Almería (South-Eastern Spain), and to identify the main predictors of exposure related to socio-economic characteristics, diet and lifestyle. METHODS: A cross-sectional study was conducted on 133 children aged 6-11 years selected from public schools of the study area. OCs compounds were determined in serum samples by GC/ECD. Anthropometric measures were obtained during sample collection. Information on sociodemographic characteristics, parental occupation, residential history, lifestyle and frequency of food consumption, among other relevant factors, was obtained by questionnaires administered to the mothers. RESULTS: Geometric means of serum concentrations (ng/ml) were 0.11 for ß-hexachloro-cyclohexane (ß-HCH), 0.09 for endosulfan, 0.20 for endosulfan-ether, 0.51 for hexachorobenzene (HCB), 0.08 for mirex, 0.06 for oxychlordane, 0.36 for p,p'-DDE, 0.20 for PCB 138, 0.36 for PCB 153, and 0.45 for PCB 180. Percentage of samples above the limit of detection (0.05 ppb) ranged from 32 (ß-HCH) to 100 (HCB). A high variability in OC levels depending on the compound was observed between our results and others found in similar studies carried out in children. Variables related to fish consumption were found to be the major dietary determinant of PCB 138, p,p´-DDE, endosulfan-α, ß-HCH, mirex and oxychlordane levels. CONCLUSIONS: Children participating in this study showed detectable levels of many OC, despite these compounds are no longer used. Their presence in children serum can be explained by their high lipophilicity and environmental persistence, leading to contamination of fatty food. In this line, fish consumption seemed to be the most relevant determinant of OC levels found in our study.

Associations of persistent organic pollutants in serum and adipose tissue with breast cancer prognostic markers.

This study aimed to evaluate associations between exposure to a group of persistent organic pollutants, measured in both adipose tissue and serum samples from breast cancer patients, and a set of tumor prognostic markers. The study population comprised 103 breast cancer patients recruited in Granada, Southern Spain. Data for tumor prognostic markers were retrieved from hospital clinical records and socio-demographic information was gathered by questionnaire. Persistent organic pollutants were quantified by gas chromatography with electron capture detection. Exposure levels were categorized in quartiles, and associations were evaluated using unconditional logistic regression. Adipose tissue HCB concentrations were associated positively with ER and PR expression (p-trends=0.044 and 0.005, respectively) and negatively with E-Cadherin and p53 expression (p-trends=0.012 and 0.027, respectively). PCB-180 adipose tissue concentrations were positively associated with HER2 expression (p-trend=0.036). Serum PCB-138 concentrations were positively associated with ER and PR expression (p-trends=0.052 and 0.042, respectively). The risk of p53 expression was higher among women in the lowest quartile of serum PCB-138 concentrations, but no significant trend was observed (p-trend=0.161). These findings indicate that human exposure to certain persistent organic pollutants might be related to breast cancer aggressiveness. We also highlight the influence on exposure assessment of the biological matrix selected, given that both serum and adipose tissue might yield relevant information on breast cancer prognosis.

A systematic review of neurodevelopmental effects of prenatal and postnatal organophosphate pesticide exposure.

Agricultural and residential use of organophosphate (OP) pesticides has increased in recent decades after banning some persistent pesticides. Although there is evidence of the effects of OPs on neurodevelopment and behaviour in adults, limited information is available about their effects in children, who might be more vulnerable to neurotoxic compounds. This paper was aimed at analysing the scientific evidence published to date on potential neurodevelopmental and behavioural effects of prenatal and postnatal exposure to OPs. A systematic review was undertaken to identify original articles published up to December 2012 evaluating prenatal or postnatal exposure to OPs in children and effects on neurodevelopment and/or behaviour. Articles were critically compared, focusing on the methodology used to assess exposure and adverse effects, as well as potential contributing factors that may modify both exposure and outcomes, such as genetic susceptibility to certain enzymes involved in OPs metabolisation (e.g. paraoxonase-1) and gender differences. Twenty articles met the inclusion criteria, 7 of which evaluated prenatal exposure to OPs, 8 postnatal exposure and 5 both pre- and postnatal exposure. Most of the studies evaluating prenatal exposure observed a negative effect on mental development and an increase in attention problems in preschool and school children. The evidence on postnatal exposure is less consistent, although 2 studies found an increase in reaction time in schoolchildren. Some paraoxonase-1 polymorphisms could enhance the association between OPs exposure and mental and psychomotor development. A large variability in epidemiological designs and methodologies used for assessing exposure and outcome was observed across the different studies, which made comparisons difficult. Prenatal and to a lesser extent postnatal exposure to OPs may contribute to neurodevelopmental and behavioural deficits in preschool and school children. Standardised methodologies are needed to allow results to be better compared and to perform a quantitative meta-analysis before drawing any final conclusions.

Changes in male hormone profile after occupational organophosphate exposure. A longitudinal study.

There is a growing concern about the endocrine effects of long-term, low-level exposure to organophosphate (OP) compounds. Studies on experimental animals have found that OP pesticides have an impact on the endocrine system and a few clinical and epidemiological studies have also shown that OPs may affect the male hormone profile, although results are inconsistent. We have evaluated the effect of exposure to OP pesticides, measured through urinary levels of six dialkylphosphate (DAP) metabolites, on male hormone profile in 136 floriculture workers from the State of Mexico and Morelos during two agricultural periods with different degree of pesticide exposure. Generalized estimated equations (GEE) models were developed and adjusted for several potential confounders, including PON1 enzyme activity, as a biomarker of susceptibility, and serum levels of p,p'-DDE, a metabolite of the pesticide DDT widely used in Mexico until 1999 for control of agricultural pests and malaria. Exposure of male floriculture workers to OP pesticides was associated with increased serum levels of follicle-stimulating hormone (FSH) and prolactin and with decreased serum testosterone and inhibin B levels. Among all DAPs tested, only DETP was inversely associated with luteinizing hormone (LH). Estradiol showed a marginally significant positive trend with DEP and DETP derivatives. In conclusion, OP pesticides may have an impact on the endocrine function because of their potential to modify the male hormone profile as a function of the type of pesticide used as well as the magnitude of exposure.