Environmental chemicals originating from human activities, such as persistent organic pollutants (POPs), may interfere with the endocrine system of aquatic organisms. The effect of these chemicals on biota and human populations is of high public concern but remains poorly understood, especially in aquatic environments of South America. The aim of this study was to investigate the bioavailability of POPs and the related effects in caged male tilapia (Oreochromis niloticus) in four cascading reservoirs of the Iguaçu River, Southern Brazil. POPs including organochlorine pesticides (OCPs), polychlorinated biphenyl (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined in the reservoir water and tissue samples of tilapia after two months of exposure. The PCB levels in water (14.7 ng L−1) were 14 times higher than the limits permitted by the Brazilian legislation in the Salto Santiago (SS) reservoir. Similarly, concentrations of aldrin and its metabolites (6.05 ng L−1) detected in the water sample of the Salto Osório (SO) reservoir were also above the permitted limits. RT-qPCR analysis revealed different transcript levels of cytochrome P450 enzymes (CYP1A and CYP3A) in the liver among the four groups, with induced activity in tilapia from the SS reservoir. Quantification of the CYP3A mRNA expression and catalytic activity showed higher values for fish caged at the SS reservoir. The fish from this site also had a higher number of eosinophils observed in the testes. Although overt measurements of endocrine disruption were not observed in caged fish, alteration of CYP enzymes with co-occurrence of organochlorine contaminants in water may suggest bioavailability of contaminants from agricultural sources to biota. Additional studies with feral or caged animals for a longer duration may be necessary to evaluate the risks of the waterways to humans and wildlife.

Most African countries have ratified the Stockholm Convention on persistent organic pollutants (POPs) and are expected to reduce emissions of POPs such as organochlorine pesticides (OCPs) to the atmosphere. Emerging evidence, however, suggests that there are contemporary sources of OCPs in African countries despite the global ban on these products. This study investigated the atmospheric contamination from OCPs in four West African countries—Togo, Benin, Nigeria, and Cameroon—to ascertain the emission levels of OCPs and the characteristic signatures of contamination. Polyurethane foam (PUF) disk passive air samplers (PAS) were deployed in each country for ca. 55 days in 2012 and analyzed for 25 OCPs. Hexachlorocyclohexanes (HCHs) and DDTs constituted the highest burden of atmospheric OCPs in the target countries, at average concentrations of 441 pg m⁻³ (range 23–2718) and 403 pg m⁻³ (range 91–1880), respectively. Mirex had the lowest concentration, ranged between 0.1 and 3.3 pg m⁻³. The concentration of OCPs in rainy season was higher than in dry season in Cameroon, and presupposed inputs from agriculture during the rainy season. The concentrations of ∑25 OCPs in each country were in the following order: Cameroon > Nigeria > Benin > Togo. There was significant evidence, based on chemical signatures of the contamination that DDT, aldrin, chlordane, and endosulfan were recently applied at certain sites in the respective countries.

Organochlorine pesticides (OCPs) were determined by gas chromatography in 241 placentas from cotton-growing regions, 121 placentas from an urban area (city of Osh), and 146 placentas from unpolluted mountain regions of Kyrgyzstan. Manifestations of disease were recorded in the mothers during pregnancy and parturition and in their newborns during the first 6 days of life. OCPs were detected in 240 out of 508 placentas (47.2%), with increased incidence in the two polluted regions (65%), particularly in placentas from women living near former pesticide storehouses and agro air-strips (99%), but only in 2.7% of placentas from the unpolluted region. α-, β-, and γ-hexachlorocyclohexane (HCH); DDT; DDE; aldrin; and heptachlor were detected. The sum of concentrations of all OCPs (total OCPs) was calculated for each of the 240 placentas with detectable OCPs (median 9.5 μg/kg placenta, mean 88.3 μg/kg, range 0.1–3070 μg/kg). The incidence of health problems in four subgroups of this data set, with increasing levels of total OCPs, was compared with the incidence of health problems in the group of 268 placentas, where OCPs were undetectable. Relative risk of health problems in both, mothers and newborns, increased significantly, in a concentration-dependent manner, with increasing levels of total OCPs (p < 0.0001). Health complications with increased incidence in OCP-exposed newborns included, i.a., low birth weight, congenital malformations, infections, and stillbirths, in OCP-exposed mothers preterm delivery, (pre-)eclampsia/gestosis, and frequency of hospitalizations after delivery (infections). Women living near former pesticide storehouses and agro airstrips should be considered as being at risk. Reduction of exposure is urgently needed.