Arsenic, Cadmium, and Lead Levels in School Meals and Their Risk Assessment in Municipalities in Bahia, Brazil.

BACKGROUND: School meals represent a significant supply of nutrients for children in Brazil, especially those in conditions of social vulnerability. OBJECTIVES: This study aimed to assess the levels of arsenic (As), cadmium (Cd), and lead (Pb) in meals served in public elementary schools in four municipalities in the state of Bahia, Brazil, and assess the risk posed to children's health. METHODS: Ninety-six samples were collected from 16 schools, freeze-dried, and subjected to microwave-assisted digestion. The As, Cd, and Pb levels were determined by graphite furnace atomic absorption spectrometry. The risk assessment was based on calculating each element's hazard quotient (HQ). RESULTS: None of the samples reached or exceeded the tolerable levels for the elements analyzed. Pb was the metal that obtained the most significant result, reaching maximum levels of 39-157 µg·kg-1. CONCLUSIONS: No element exceeded the PTWI proposed by JECFA; thus, the toxic metal content in school meals poses a negligible risk to children's health.

A Cross-Sectional Analysis Investigating Pregnant Women's Renal Function and Its Association with Lead and Cadmium Exposures-The DSAN Birth Cohort Study in Recôncavo Baiano, Brazil.

Kidney dysfunction is increasing worldwide and is exacerbated by exposure to toxic metals. Also, pregnancy poses an overload on kidney function. We investigated how blood lead (PbB) and cadmium (CdB) levels were associated with kidney function in pregnant women from Recôncavo Baiano, Brazil, during their second trimester. In this cross-sectional study, the estimated glomerular filtration rate (eGFR) was calculated from serum creatinine and whole blood metal levels were measured by graphite furnace atomic absorption spectrophotometry in 136 volunteers. Sociodemographic data were collected using semi-structured questionnaires. The medians (IQR) of PbB, CdB, and eGFR were 0.85 µg/dL (0.45-1.75), 0.55 µg/L (0.08-0.91), and 121.8 mL/min/1.73 m2 (106.0-127.9), respectively. PbB medians were significantly higher in the eGFR < 90 group at 2.00 µg/dL (0.83, 3.10). After age-adjusted logistic regression, pregnant women with elevated PbB levels had decreased eGFR (OR = 1.82; 95%-CI, 1.14-3.14). However, the participants with elevated PbB levels who reported consuming alcohol during pregnancy or had CdB in the highest tertile had higher odds of reduced eGFR (OR = 2.44; 95%-CI, 1.30-5.47) and (OR = 11.22; 95% CI, 2.53-103.51), respectively. These results suggest that low Pb exposure may affect kidney function in pregnant women and calls for further investigation into toxic metal co-exposures on kidney function during pregnancy in at-risk communities.

Prenatal current-use pesticide exposure and children's neurodevelopment at one year of age in the Infants' Environmental Health (ISA) birth cohort, Costa Rica.

BACKGROUND: Pesticide exposure may affect young children's neurodevelopment, but only few cohort studies have addressed possible effects of non-organophosphate pesticides. OBJECTIVE: We evaluated associations between prenatal current-use pesticide exposure and neurodevelopmental outcomes among 1-year-old children from the Infants' Environmental Health (ISA) birth cohort. METHODS: To determine prenatal pesticide exposure, we measured biomarkers of pyrimethanil, chlorpyrifos, synthetic pyrethroids, and 2,4-D in urine samples among 355 women, 1-3 times during pregnancy. One-year post-partum, we evaluated children's neurodevelopment with the Bayley Scales of Infant and Toddler Development 3rd edition (BSID-III). We assessed associations between exposures and neurodevelopmental outcomes (composite and z-scores) using single-chemical linear regression models adjusted for possible confounders (maternal education, parity, sex, gestational age at birth, child age, HOME-score, location of assessment, biomarkers of mancozeb), and studied effect-modification by sex. We evaluated non-linear associations of multiple pesticide exposures with Bayesian kernel machine regression (BKMR). RESULTS: We found higher prenatal urinary 2,4-D concentrations were associated with lower language (ßper ten-fold increase = -2.0, 95 % confidence interval (CI) = -3.5, -0.5) and motor (ßper ten-fold increase = -2.2, 95 %CI = -4.2, -0.1) composite scores among all children. Also, higher chlorpyrifos exposure [measured as urinary 3,5,6-trichloro-2-pyridinol (TCPy)] was associated with lower cognitive composite scores (ßper ten-fold increase = -1.9, 95 %CI = -4.7, 0.8), and lower motor composite scores among boys (ßper ten-fold increase = -3.8, 95 % CI = -7.7, 0.1) but not girls (ßper ten-fold increase = 2.3, 95 %CI = -1.6, 6.3, pINT = 0.11). Finally, higher pyrimethanil was associated with lower language abilities among girls, but not boys. Pyrethroid metabolite concentrations did not explain variability in BSID-III composite scores. Associations were similar for BSID-III z-scores, and we found no evidence for non-linear associations or mixture effects. DISCUSSION: Prenatal exposure to common-use pesticides may affect children's neurodevelopment at 1-year of age, some effects may be sex-specific.

Maternal Exposure to Potentially Toxic Metals and Birth Weight: Preliminary Results from the DSAN-12M Birth Cohort in the Recôncavo Baiano, Brazil.

Prenatal exposure to potentially toxic metals (PTM) may impair fetal growth (FG). We investigated the relationship between maternal exposure to lead (Pb), cadmium (Cd) and manganese (Mn) and birth weight (BW) of 74 newborns. Blood was collected during the second trimester of pregnancy to determine Pb (PbB) and Cd (CdB), while hair (MnH) and toenails (MnTn) were used for Mn. Samples were analyzed by graphite furnace atomic absorption spectrophotometry (GFAAS). Sociodemographic and BW data were collected from questionnaires and maternity records, respectively. The medians (P25th-P75th) of PbB, CdB, MnH, and MnTn were, respectively, 0.9 (0.5-1.8) µg/dL; 0.54 (0.1-0.8) µg/L; 0.18 (0.1-0.4) µg/g; and 0.65 (0.37-1.22) µg/g. The means (standard deviation) of birth weight according to sex were 3067 (426.3) and 3442 (431) grams, respectively, for girls and boys. MnTn presented an inverse correlation with the BW/gestational age ratio for girls (rho = -0.478; p = 0.018), suggesting the effect of sex modification. Although BW correlation with CdB was not statistically significant, hierarchical linear regression (beta = -2.08; 95% CI-4.58 to 0.41) suggested a fetotoxic effect. These results confirmed the threat PTMs may represent and the need for more extensive research to elucidate their role in inadequate FG in developing countries.

Determinants of Exposure to Potentially Toxic Metals in Pregnant Women of the DSAN-12M Cohort in the Recôncavo Baiano, Brazil.

Exposure to potentially toxic metals (PTM) threatens maternal and child health. We investigated the determinants of exposure to lead (Pb), cadmium (Cd), arsenic (As), and manganese (Mn) in 163 pregnant women from the Recôncavo Baiano, Brazil, enrolled in the DSAN-12M cohort. We measured these metals in biological samples (blood, toenails, and hair) and the Pb dust loading rates (RtPb) at their homes by graphite furnace atomic absorption spectrophotometry (GFAAS). Questionnaires were applied to collect sociodemographic and general habits data. Only 2.91% (n = 4) of the pregnant women had As levels above the detection limit. Few participants had levels above the recommended reference values for blood Pb (5.1; 95% CI: 2.1-10.1%), and Mn in hair or toenails (4.3; 95% CI: 2.3-10.1%). On the other hand, 61.1 (95% CI: 52.4-69.3%) had elevated blood Cd levels. After binary logistic regression, low socioeconomic status, domestic waste burning, being a passive smoker, multiparity, and renovating the house significantly increased the chances of having high levels of Mn, Pb, and Cd. We detected a worrying situation related to exposure to Cd, showing the urgency of implementing human biomonitoring in the general population, especially in situations of social vulnerability.

Protective Effects of Flavonoid Rutin Against Aminochrome Neurotoxicity.

Causes of dopaminergic neuronal loss in Parkinson's disease (PD) are subject of investigation and the common use of models of acute neurodegeneration induced by neurotoxins 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), 6-hydroxydopamine, and rotenone contributed to advances in the study of PD. However, the use of study models more similar to the pathophysiology of PD is required for advances in early diagnosis and translational pharmacology. Aminochrome (AMI), a compound derived from dopamine oxidation and a precursor of neuromelanin, is able to induce all the mechanisms associated with neurodegeneration. Previously, we showed AMI is cytotoxic in primary culture of mesencephalic cells (PCMC) and induces in vitro and in vivo neuroinflammation. On the other hand, the effect of rutin in central nervous system cells has revealed anti-inflammatory, antioxidative, and neuroprotective potential. However, there have been no data studies on the effect of rutin against aminochrome neurotoxicity. Here, we show that rutin prevents lysosomal dysfunction and aminochrome-induced cell death in SHSY-5Y cells, protects PCMC against aminochrome cytotoxicity, and prevents in vivo loss of dopaminergic neurons in substantia nigra pars compacta (SNPc), as well as microgliosis and astrogliosis. Additionally, we show that rutin decreases levels of interleukin-1ß (IL-1ß) mRNA and increases levels of glia-derived neurotrophic factor (GDNF) and nerve-derived neurotrophic factor (NGF) mRNA. We evidence for the first time the protective effect of rutin on PD aminochrome-induced models and suggest the potential role of the anti-inflammatory activity and upregulation of NGF and GDNF in the mechanism of rutin action against aminochrome neurotoxicity.

Executive functions in school-aged children exposed to airborne manganese: A multilevel analysis.

Neuropsychological alterations have been identified in populations heavily exposed to metals with neurotoxic potential, such as manganese (Mn). This study examined the associations between Mn environmental exposure in school-aged children and executive functions, using structural equation modeling. Children, aged between 7 and 12 years (N = 181), were recruited from four elementary schools located in a region that is under the influence of atmospheric emissions from a ferro-manganese alloy plant in the municipality of Simões Filho, Bahia, Brazil. The following cognitive functions were evaluated: Intelligence, Inhibitory Control, Cognitive Flexibility, Verbal and Design Fluency, Verbal and Visual Working Memory and Attention. We performed structural equation modeling to identify the following executive functions latent variables: working memory, inhibitory control and cognitive flexibility. We further analyzed the relations between executive functions and Mn measured in hair (MnH) and toenails (MnTn) with linear mixed models, after controlling for co-variables. A positive effect at the individual level on working memory, inhibition control and cognitive flexibility was observed with MnTn after controlling for co-variables, but no association was found with MnH levels. However, children attending school most environmentally exposed to Mn emissions, which had the highest rate of Mn dust deposition, had the poorest scores on working memory. These findings suggest both benefits and risk of Mn on children's cognitive development.

Delta-Aminolevulinic Acid Dehydratase, Low Blood Lead Levels, Social Factors, and Intellectual Function in an Afro-Brazilian Children Community.

Delta-aminolevulinic acid dehydratase (ALAD) enzyme catalyzes the second phase of the heme biosynthesis and is involved in lead toxicokinetics. This research aimed to evaluate its influence on the relationship between blood lead (PbB) levels and intellectual performance in Afro-Brazilian children. PbB, hemoglobin concentration, ALAD activity, and polymorphism were determined in whole blood. Anthropometric, socioeconomic, and family environment stimuli data were collected with appropriate instruments. The non-verbal intelligence of children and their mothers or guardians was assessed using the correspondent Raven's Progressive Matrix versions. The medians (range) of PbB levels and ALAD activity were 1.0 µg/dL (0.1-21.3) and, 71 U/L (31-113), respectively. ALAD G177C was distributed as follows: 97.9% for ALAD1/1 and 2.1% for ALAD1/2 genotypes. The mean of Raven raw score was 19.3 (± 5.6) points and there were no differences according to sex or environmental Pb exposure. No statistically significant association was observed between PbB level and children's IQ. However, ALAD activity presented an inverse significant association with PbB levels, children's percentile IQ, and children's IQ/Age ratio, suggesting a neuroprotective role of ALAD1 genotype in those with low PbB level.

Biomarkers of cadmium exposure and renal function in estuarine adult villagers.

OBJECTIVE: Assess cadmium (Cd) exposure of adults living in two estuarine communities in Aratu bay, Bahia, Brazil and its association with effects on renal function. METHODS: This cross-sectional study included 88 volunteers aged 17-55 years, living in the following two communities: Santa Luzia (SL) located more intimately in the bay and Cotegipe (CT), a bit further and closer to a ferro-manganese alloy plant. Cd in blood (CdB) and urine (CdU), along with blood lead (PbB) levels were determined by graphite furnace atomic absorption spectrometry. Renal function was evaluated by the estimated glomerular filtration rate (eGFR) and tubular cell biomarkers: retinol binding protein (RBP), ß2-microglobulin (ß2M), and N-acetyl-ß-D-glucosaminidase (NAG). RESULTS: The median CdU levels in villagers of the two communities were 0.20 and 0.44 µg/g creat. and SL vs CT, respectively. Age range (> 35 years), cigarette smoking and lower family income were significantly associated with more elevated CdU levels. Multiple linear regression analysis demonstrated a significant association between LnCdU and LnRBP levels (ß = 0.200, 95%CI 0.074-0.365) after adjusted for sex, urinary creatinine and blood lead levels. CONCLUSION: These data show consistent evidences of association between Cd exposure and elevated tubular cell biomarker excretion in estuarine villagers living close to an industrial site.

Assessment of potters' occupational exposure to lead and associated risk factors in Maragogipinho, Brazil: preliminary results.

BACKGROUND AND PURPOSE: Lead (Pb) is used as a flux in the glazing process of pottery utensils in several regions of the world. It can affect the nervous and hematopoietic systems; in addition, it is classified as a probable human carcinogen. This work aims to evaluate Pb exposure of potters and describe the main determinants of elevated blood Pb (PbB) levels in this group of workers. METHODS: This is a cross-sectional study with potters of Maragogipinho Village, Bahia, Brazil, of both sexes, aged 16-72 years (n = 85). Non-exposed workers of the same age range residing in the urban area of Aratuípe town were also recruited (n = 50). We evaluated Pb dust deposition rates (PbDrt) in pottery workshops and PbB levels. All Pb measurements were performed by Graphite Furnace Atomic Absorption Spectrometry. RESULTS: The median of PbB (min-max) and geometric mean (SD) PbDrt for the exposed group were 7.9 (0.9-49.8) µg/dL and 1463 (± 290,000) µg/m2/30 days, respectively. For the control group, levels were 1.5 (0.1-19.8) µg/dL and 82 (46) µg/m2 30 days, respectively. CONCLUSION: The data found showed an excessive exposure among artisans, exceeding occupationally safe levels and those reported in the literature. It is important to implement occupational hygiene measures and improvements of the working conditions of these labors, especially the replacement of lead oxide in the pottery-glazing process.

Zinc-protoporphyrin determination by HPLC with fluorescence detection as a biomarker of lead effect in artisanal pottery workers.

Lead (Pb) exposure compromises heme synthesis by inhibiting ferrochelatase, forming zinc-protoporphyrin (ZnPP). This study aims to validate a method for the determination of ZnPP by HPLC with fluorescence detection and apply this method to evaluate the extent of Pb exposure of artisanal pottery workers. Extraction procedures were tested using both nonacid and acid liquid-liquid extraction. The former presented a better chromatogram and recovery results. The validated method yielded a good resolution of ZnPP and its free form peaks with acceptable precision and accuracy. Total run time was 15 min and ZnPP peak retention time was 5.6 min. We applied this method to evaluate 39 potters (90% male), mean age 40 years (9-80). The medians (ranges) of blood lead, ZnPP and hemoglobin were 16.0 µg/dl (2.2-71.5), 12.6 µg/dl (4.6-279.8) and 15.1 g/dl (11.0-17.8), respectively. Significant differences were observed for blood lead according to gender, age range (>40 years), direct handling of lead oxide and years of occupation. Significantly higher levels of ZnPP were observed in male potters involved with lead glazing activity. The validated method was shown to be simple with one-step nonacid extraction, good sensitivity, reproducibility and accuracy. Our data shows that these laborers are dangerously exposed to Pb, reflecting the effect on the heme synthesis.

Metal Content of Nutritional and Toxic Value in Different Types of Brazilian Propolis.

Brazilian raw propolis samples (brown, green, red, and yellow) were investigated to evaluate the content of three elements of nutritional value (Cu, K, and Se) and three toxic metals (As, Cd, and Pb). The propolis samples (n = 19) were obtained from different regions of Brazil and analysed by atomic absorption spectrometry after microwave-assisted digestion. A descriptive analysis of the variables was carried out, and nonparametric tests (Kruskal-Wallis or Mann-Whitney) were performed to verify the differences in metal contents. The elemental concentrations of the Brazilian propolis were in the following ranges: As < 0.048-8.47 µg·g-1, Pb < 0.006-0.72 µg·g-1, Cu 0.57-11.60 µg·g-1, Se < 0.041-0.54 µg·g-1, and K 0.23-7.94 mg·g-1; Cd was below LOD (0.008 µg·g-1) in all samples, except one. Seven samples exceeded the limits defined for As or Pb by the Brazilian regulation.

Environmental exposure to lead and hematological parameters in Afro-Brazilian children living near artisanal glazed pottery workshops.

This study aimed to evaluate the exposure to environmental lead (Pb) of children from a traditional community of African descent in Brazil and the effects on hematological parameters. Children (n = 75) aged 5.5-13 years from the exposed areas classified as low (LEx) and moderately (MEx) exposed were compared with children (n = 75) of a control group (CG). Dust Pb loading rates (RtPbs) at children's homes were measured. Peripheral venous blood samples were collected to assess Pb biomarkers of exposure and effects. All Pb determinations were performed by graphite furnace atomic absorption spectrometry. The median (IQR) of RtPb, PbB level, and ALA-D activity were 65 (25-137) µgPb/m2/30 days, 1.0 (0.1-2.8) µg/dL, and 71 (55-86) U/L, respectively. Spearman correlation evidenced the relationship of PbB with RtPb (rho = 0.368, P < 0.001) and ALA-D activity (rho = -0.587; P ˂ 0.001). After adjusting for exposure degree and child's age, a decline of 7.4 U/L in ALA-D activity was associated with a 10-fold increase in PbB. The prevalence ratio of elevated PbB (>5 µg/dL) in LEx and MEx areas were 1.5 and 3.7, respectively. Indoor dust exposure, living near pottery workshops and the secondary exposure were the main determinants of elevated PbB levels, which were associated with hematological effects.

Caregiving and infants' neurodevelopment in rural Costa Rica: Results from the Infants' Environmental Health Study (ISA).

Early caregiving is one of the strongest influences on children's development, and among the most significant modifiable environmental factor. The aim of this study was to explore the association between quality of caregiver-infant interactions and neurodevelopment of infants living in banana-growing communities in rural Costa Rica characterized as having environmental toxic exposures. Home visits were conducted with 94 caregiver-infant dyads from the Infants' Environmental Health Study (ISA), living within Matina county, Limón province. One-year infant neurodevelopmental outcomes were assessed using the Bayley Scales of Infant and Toddler Development®, Third Edition (Bayley-III). Quality of caregiver-infant interaction was assessed with a standardized observational task: Nursing Child Assessment Satellite Training Teaching scale (NCATS) at around two years of age. Multiple regression analyses examined associations between components of caregiver-infant interactions and neurodevelopmental outcomes, adjusting for mancozeb and manganese exposure and other potential confounders. Compared to NCATS normative data for U.S. Hispanic mothers, 35% of the sample had overall caregiving interaction scores ≤10th percentile cut-off, indicating less than optimal interactions. Higher quality of caregiver-infant interaction was associated with higher expressive communication ability in infants [ß = 0.03 (95% CI: 0.01, 0.06)], controlling for pesticide exposure and confounders. Aspects of caregiving such as stimulation and growth-fostering of infants were most strongly associated with language outcomes. Results suggest an association between positive caregiving on language development for infants living in a rural agricultural area in Costa Rica, and highlight aspects of caregiving that could be targeted to improve resilience of these children who live in vulnerable conditions.

Manganese exposure and working memory-related brain activity in smallholder farmworkers in Costa Rica: Results from a pilot study.

Main sources of manganese (Mn) in the general population are diet and drinking water. Mn is also found in ethylene bisdithiocarbamate (EBDC) fungicides used in agriculture or emitted into the air by ferromanganese plants and welding fumes, which can be additional environmental and occupational sources of exposure. High occupational Mn exposure has been linked with motor, behavioral, and cognitive impairment, but its effects on neural function remain poorly understood. We conducted a functional neuroimaging study in a sample of 48 farmworkers in Zarcero County, Costa Rica, an agricultural region where EBDC fungicides are sprayed. We measured Mn concentrations in farmworkers' toenails (n = 40 farmworkers) and hair (n = 33 farmworkers), and recorded brain activity in the dorsolateral prefrontal cortex during a letter-retrieval working memory task using functional near-infrared spectroscopy (fNIRS). We estimated exposure-outcome associations using multivariable linear regression models adjusted for age and education level. Geometric mean (geometric standard deviation) toenail and hair Mn concentrations were 0.40 µg/g (3.52) and 0.24 µg/g (3.54), respectively. We did not find strong evidence that Mn concentrations were associated with working memory-related brain activity in this sample of farmworkers; we also found null associations between working memory task accuracy and brain activity. However, our small sample size may have limited our ability to detect small effect sizes with statistical precision. Our study demonstrates that fNIRS can be a useful and feasible tool in environmental epidemiology for examining the effects of toxicants, like Mn, on neural function. This may prove to be important for elucidating neuropathological pathways that underlie previously reported associations of elevated Mn exposure with neurotoxic effects.

Manganese exposure and association with hormone imbalance in children living near a ferro-manganese alloy plant.

It has been suggested that manganese (Mn) plays a fundamental role in the reproductive system through interference with the regulation of the secretion of hormones related to puberty. The objective of this study was to evaluate the environmental exposure to Mn and its effects on the endocrine regulation of hormones related to puberty in school-aged children living near a ferro-manganese alloy plant. Toenails, occipital hair, and blood samples were collected from 225 children, between 7 and 12 years of age, in four elementary schools in Simões Filho, Bahia, Brazil, who were exposed to different Mn levels owing to different Mn dust deposition rates. The Mn content was determined in the toenails (MnTn), hair (MnH), and blood (MnB), in addition to blood lead levels (PbB), by using graphite furnace atomic absorption spectrometry. Luteinizing hormone (LH), prolactin (PRL), estradiol (E2), testosterone (T), and thyroid stimulating hormone (TSH) levels were determined by using a chemiluminescence method. Of the total participants, 50.2% were boys, with an average age of 9 years. PRL values were higher in children attending the school with a higher Mn deposition rate (p < 0.004). We observed that MnTn was positively correlated with PRL levels and exhibited a non-linear association with LH levels. None of the tested Mn biomarkers were associated with E2, T, or TSH levels. To date, despite several animal studies that have focused on the correlation between Mn exposure and the endocrine regulation of hormones and pubertal development, very few studies have reported a similar relationship between environmental Mn effects and the human endocrine system. Our findings support the hypothesis that elevated exposure to Mn in children may be associated with hormonal imbalances that might trigger the early onset of puberty.

Exposure to Pesticides and Health Effects on Farm Owners and Workers From Conventional and Organic Agricultural Farms in Costa Rica: Protocol for a Cross-Sectional Study.

BACKGROUND: Pesticide use is increasing in low- and middle-income countries (LMICs) including Costa Rica. This increase poses health risks to farm owners, farm workers, and communities living near agricultural farms. OBJECTIVE: We aimed to examine the health effects associated with occupational pesticide exposure in farm owners and workers from conventional and organic smallholder farms in Costa Rica. METHODS: We conducted a cross-sectional study involving 300 owners and workers from organic and conventional horticultural smallholder farms in Zarcero County, Costa Rica. During the baseline study visit, we administered a structured, tablet-based questionnaire to collect data on sociodemographic characteristics, pesticide exposure, and health conditions (eg, respiratory and allergic outcomes and acute pesticide intoxication symptoms) and administered a neurobehavioral test battery (eg, Finger Tapping Test and Purdue Pegboard); we measured blood pressure, anthropometry (height, weight, and waist circumference), and erythrocytic acetylcholinesterase activity and also collected urine samples. In addition, a functional neuroimaging assessment using near-infrared spectroscopy was conducted with a subset of 50 study participants. During the follow-up study visit (~2-4 weeks after the baseline), we administered participants a short questionnaire on recent pesticide exposure and farming practices and collected hair, toenail, and urine samples. Urine samples will be analyzed for various pesticide metabolites, whereas toenails and hair will be analyzed for manganese (Mn), a biomarker of exposure to Mn-containing fungicides. Self-reported pesticide exposure data will be used to develop exposure intensity scores using an exposure algorithm. Furthermore, exposure-outcome associations will be examined using linear and logistic mixed-effects regression models. RESULTS: Fieldwork for our study was conducted between May 2016 and August 2016. In total, 113 farm owners and 187 workers from 9 organic and 83 conventional horticultural smallholder farms were enrolled. Data analyses are ongoing and expected to be published between 2019 and 2020. CONCLUSIONS: This study is one of the first to examine differences in health effects due to pesticide exposure between farm owners and workers from organic and conventional smallholder farms in an LMIC. We expect that this study will provide critical data on farming practices, exposure pathways, and how occupational exposure to pesticides may affect farm owners and workers' health. Finally, we hope that this study will allow us to identify strategies to reduce pesticide exposure in farm owners and workers and will potentially lay the groundwork for a future longitudinal study of health outcomes in farm owners and workers exposed to pesticides. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/10914.

Environmental Co-Exposure to Lead and Manganese and Intellectual Deficit in School-Aged Children.

Studies have demonstrated that, for urban children, dust represents the main exposure to sources of metals like lead (Pb) and manganese (Mn). We aimed to investigate the exposure to these metals and their association with intellectual deficit in children living in an industrial region. This cross-sectional study recruited volunteers from four elementary schools in the town of Simões Filho, Brazil. We evaluated 225 school-aged children (7⁻12 years) for blood lead (PbB) and manganese hair (MnH) and toenails (MnTn) by graphite furnace atomic absorption spectrometry. Child and maternal IQs were estimated using the Wechsler Abbreviated Scale for Intelligence (WASI). Median and range PbB were 1.2 (0.3⁻15.6) µg/dL. MnH and MnTn medians (ranges) were 0.74 (0.16⁻8.79) µg/g and 0.85 (0.15⁻13.30) µg/g, respectively. After adjusting for maternal IQ, age and Mn exposure, child IQ drops by 8.6 points for a 10-fold increase in PbB levels. Moreover, an effect modification of Mn co-exposure was observed. In children with low MnTn, association between Pb and child IQ was not significant (ß = -6.780, p = 0.172). However, in those with high MnTn, the association was increased by 27.9% (ß = -8.70, p = 0.036). Low Pb exposure is associated with intellectual deficit in children, especially in those with high MnTn.

Airborne manganese exposure and neurobehavior in school-aged children living near a ferro-manganese alloy plant.

Excessive exposure to Mn can lead to its accumulation in the brain with neurotoxic consequences. In children, elevated Mn has been associated with deficits in certain neuropsychological domains such as cognition, motor function, memory and attention, and in some instances, hyperactivity and behavioral problems. The aim of this study was to evaluate behavioral effects in school-aged children living near a ferro-manganese alloy plant and examine their association with Mn exposure. Occipital hair, toenails and blood samples were collected from 225 children (7-12 years old) enrolled in four elementary schools with different levels of exposure to Mn, based on dust Mn deposition rates. Full data set collection was completed and run from 165 children. Mn in hair (MnH), toenails (MnTn), blood (MnB) and blood lead levels (PbB) were determined by graphite furnace atomic absorption spectrometry. Children's behavior was assessed with the Child Behavior Check List (CBCL) reported by parents. Median levels and range of MnH, MnT and MnB were, respectively, 0.73 µg/g (0.16-8.79), 0.84 µg/g (0.15-9.29) and 8.98 µg/L (1.51-40.43). Median and range of PbB were 1.2 µg/dL (0.2-15.6). MnH and MnB were not associated with any scale of the CBCL behavior scores. We found a positive association between logMnTn and raw total CBCL score (ß = 10.17, p = 0.034), adjusting for sex, age, maternal IQ and logPbB. Analyses using Generalized Additive Model showed non-linear associations between MnTn and externalizing behavior (p = 0.035), as well as with the related subscales: aggressive behavior (p = 0.045) and rule-breaking behavior (p = 0.024). Further positive associations were observed between MnTn and thought problems (p = 0.031) and social problems (p = 0.027). These findings corroborate previous studies showing an association between Mn exposures and externalizing behavior. Our results suggest that toenail Mn, as a biomarker of environmental exposure, is associated with disruptive behavior in children living near a ferro-manganese alloy plant.

School meals' centesimal and mineral composition and their nutritional value for Brazilian children.

The assessment of meals served under the Brazilian National School Meal Program (PNAE) is an important tool to verify its adequacy to the proposed parameters and the nutritional needs of school-aged children. The aim of this study was to evaluate the centesimal and mineral composition of the meals offered by the program and adequacy to the nutritional recommendations in three municipalities of the state of Bahia, Brazil. Centesimal composition of meals was determined according to the reference guidelines and mineral composition was analyzed by atomic absorption spectrometry. Non-parametric analysis of variance was used to test the differences of the medians among the municipalities and Student-t test to compare the means between the two sampling periods. There were inadequacies in the carbohydrate, lipid and protein contents, and none of the municipalities reached the recommendation of 20%. Mineral concentration, especially Fe, Se, Cu and K were much lower than expected. Sodium levels were three-folds higher than the recommended, being worrisome due to higher risk of elevated blood pressure. There were inadequacies with regard to the PNAE guidelines, and there is a need to reevaluate the meals that are being offered to better meet childrens needs and to form healthy habits from childhood.