Uncovering the impact of agricultural activities and urbanization on rivers from the Piracicaba, Capivari, and Jundiaí basin in São Paulo, Brazil: A survey of pesticides, hormones, pharmaceuticals, industrial chemicals, and PFAS.

Rivers in Southeast Brazil are essential as sources of drinking water, energy production, irrigation, and industrial processes. The Piracicaba, Capivari, and Jundiaí rivers basin, known as the PCJ basin, comprises major cities, industrial hubs, and large agricultural areas, which have impacted the water quality in the region. Emerging contaminants such as pesticides, hormones, pharmaceuticals, industrial chemicals, and per- and polyfluoroalkyl substances (PFAS) are likely to be released into the rivers in the PCJ basin; however, the current Brazilian legislation does not require monitoring of most of these chemicals. Thus, the extent of emerging contaminants pollution and their risks to aquatic and human life in the basin are largely unknown. In this study, we investigated the occurrence of several pesticides, hormones, pharmaceuticals, and personal care products in 15 sampling points across the PCJ basin, while industrial chemicals and PFAS were assessed in 11 sampling points. The results show that agriculture and industrial activities are indeed causing the pollution of most rivers. Multivariate analysis indicates that some sampling points, such as Jundiaí, Capivari, and Piracicaba rivers, are largely impacted by pesticides used in agriculture. In addition, to the best of our knowledge, this is the first study reporting the presence of PFAS in rivers in São Paulo, the most populous state in Brazil. Four out of eight species of PFAS assessed in our study were detected in at least 5 sampling points at concentrations ranging from 2.0 to 50.0 ng L-1. The preliminary risk assessment indicates that various pesticides, caffeine, industrial chemicals, and PFAS were present at concentrations that could threaten aquatic life. Notably, risk quotients of 414, 340, and 178 were obtained for diuron, atrazine, and imidacloprid, respectively, in the Jundiaí River. Our study suggests that establishing a comprehensive monitoring program is needed to ensure the protection of aquatic life and human health.

Can the insecticide Imidacloprid affect the health of the Neotropical freshwater fish Astyanax altiparanae (Teleostei: Characidae)?

Female juveniles of the Neotropical fish Astyanax altiparanae were exposed for 96 h to four treatments containing the active ingredient from Imidacloprid® commercial formulation (IMI 1, IMI 2, IMI 3, and IMI 4) and to a control treatment (only dechlorinated tap water). Glutathione content, glutathione S-transferase activity, lipid peroxidation (LPO) and protein carbonylation levels, acetylcholinesterase (AChE) activity, and frequency of micronuclei and erythrocyte nuclear abnormalities (ENA) were measured in the fish. The muscle and gills were the most affected organs; their antioxidant defense was not enough to prevent oxidative damage (LPO) in the IMI 2 and IMI 4 treatment fish. IMI also inhibited AChE activity in the muscle (IMI 3 and IMI 4) and increased ENA frequency (IMI 4). IMI can affect the health of A. altiparanae in environmentally relevant concentrations, causing oxidative damage in different organs, neurotoxic effects in the muscle, and genotoxicity.

Occurrence of pesticides in waters from the largest sugar cane plantation region in the world.

In this study, a multi-residue method was used to analyze 13 pesticides and 1 degradation product in surface and groundwater in the region with the largest sugar cane production in the world. The potential effects of individual pesticides and their mixtures, for aquatic life and human consumption, were evaluated. For the surface water, 2-hydroxy atrazine, diuron, carbendazim, tebuthiuron, and hexazinone were the most frequently detected (100, 94, 93, 92, and 91%, respectively). Imidacloprid (2579 ng L-1), carbendazim (1114 ng L-1), ametryn (1101 ng L-1), and tebuthiuron (1080 ng L-1) were found at the highest concentrations. For groundwater, tebuthiuron was the only quantified pesticide (107 ng L-1). Ametryn, atrazine, diuron, hexazinone, carbofuran, imidacloprid, malathion, carbendazim, and their mixtures presented risk for the aquatic life. No risk was observed for the pesticides analyzed in this work, alone or in their mixtures for human consumption.

DNA damage and oxidative stress induced by imidacloprid exposure in different tissues of the Neotropical fish Prochilodus lineatus.

Imidacloprid (IMI), a systemic neonicotinoid insecticide widely used in worldwide scale, is reported in freshwater bodies. Nevertheless, there is a lack of information about IMI sublethal effects on freshwater fish. Thus, the aim of this study was to identify the potential hazard of this insecticide to the South American fish Prochilodus lineatus exposed for 120 h to four IMI concentrations (1.25, 12.5, 125, and 1250 µg L-1). A set of biochemical, genotoxic and physiological biomarkers were evaluated in different organs of the fish. IMI exposure induced significant changes in the enzymatic profiles of P. lineatus, with alterations in the activity of biotransformation and antioxidant enzymes in different tissues. Redox balance of the tissues was affected, since oxidative damage such as lipoperoxidation (LPO) and protein carbonylation (PCC) were evidenced in the liver, gills, kidney and brain of fish exposed to different IMI concentrations. Fish exposed to all IMI concentrations showed decreased blood glucose indicating an increase of energetic demand. DNA damage was evidenced by the comet test, in the erythrocytes of fish all the concentrations evaluated. We integrated these results in the Integrated Biomarker Response (IBR) index, which evidenced that the organs most affected by IMI exposure were the liver and kidney, followed by the gills. Our results highlight the importance of investigating different target tissues after IMI exposure and show the sublethal effects of IMI in some of them; they also warn to the possible consequences that fish living in freshwater ecosystems can suffer due to IMI exposure.