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.

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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 exposureoutcome associations using multivariable linear regression models adjusted for age and education

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Background: Animal studies have shown that both deficiency and excess manganese (Mn) may result in decreased fetal size and weight, but human studies have reported inconsistent results. Methods: We examined the association of blood and hair Mn concentrations measured at different times during pregnancy with fetal growth among term births and length of gestation in a cohort of 380 mother-infant pairs living near banana plantations aerially sprayed with Mn-containing fungicides in Costa Rica. We used linear regression and generalized additive models to test for linear and nonlinear associations Results: Mean (7 SD) blood Mn concentration was 24.47 6.6 μg/L and geometric mean (geometric SD) hair Mn concentration was 1.8 (3.2) μg/g. Hair Mn concentrations during the second and third trimesters of gestation were positively related to infant chest circumference (β for 10-fold increase¼ 0.62 cm; 95% CI: 0.16, 1.08; and β¼ 0.55 cm; 95% CI: À 0.16, 1.26, respectively). Similarly, average maternal hair Mn concentrations during pregnancy were associated with increased chest circumference (β for 10-fold increase¼ 1.19 cm; 95% CI: 0.43, 1.95) in infants whose mothers did not have gestational anemia, but not in infants of mothers who had gestational anemia (β ¼0.39 cm; 95% CI: À 0.32, 1.10; p INT ¼0.14). All these associations were linear. Blood Mn concentrations did not show consistent linear nor nonlinear relationships with any of the birth outcomes Conclusions: Mn plays an important role in fetal development, but the extent to which environmental exposures may cause adverse health effects to the developing fetus is not well understood. Among women living near banana plantations in Costa Rica, we did not observe linear or nonlinear associations of Mn concentrations with lowered birth weight or head circumference, as reported in previous studies. However, we did find positive linear associations between maternal hair Mn concentrations during pregnancy and infant chest circumference.