Bentazone in water and human urine in Wuhan, central China: exposure assessment

An Integrated Approach of Bioassays and Non-Target Screening for the Assessment of Endocrine-Disrupting Activities in Tap Water and Identification of Novel Endocrine-Disrupting Chemicals

The safety of drinking water is a significant environmental issue of great concern for human health since numerous contaminants are often detected in drinking water and its sources. Boiling is a common household method used to produce relatively high-quality drinking water in some countries and regions. In this study, with the aid of an integrated approach of in vitro bioassays and non-target analysis based on high-resolution mass spectrometry coupled with liquid chromatography, alterations in endocrine-disrupting activities in tap water samples without and with boiling were revealed, as well as the potential endocrine-disrupting chemicals (EDCs) contributing to these alterations were identified. The organic extracts of tap water had no significant (ant)agonistic activities against an estrogen receptor (ER), progesterone receptor (PR), glucocorticoid receptor (GR), and mineralocorticoid receptor (MR) at enrichment concentrations of ≤10 times, posing no immediate or acute health risk to humans. However, the presence of agonistic activities against PR and MR and antagonistic activities against ER, PR, GR, and MR in OEs of tap water at relatively higher enrichment concentrations still raise potential health concerns. Boiling effectively reduced antagonistic activities against these steroid hormone receptors (SHRs) but increased estrogenic and glucocorticoid activities in drinking water. Four novel potential EDCs, including one UV filter (phenylbenzimidazole sulfonic acid, PBSA) and three natural metabolites of organisms (beta-hydroxymyristic acid, 12-hydroxyoctadecanoic acid, and isorosmanol) were identified in drinking water samples, each of which showed (ant)agonistic activities against different SHRs. Given the widespread use of UV filters in sunscreens to prevent skin cancer, the health risks posed by PBSA as an identified novel EDC are of concern. Although boiling has been thought to reduce the health risk of drinking water contamination, our findings suggest that boiling may have a more complex effect on the endocrine-disrupting activities of drinking water and, therefore, a more comprehensive assessment is needed.

Caenorhabditis elegans as a suitable model to evaluate the toxicity of water from Rolante River, southern Brazil

Urbanization and agricultural activities increased environmental contaminants. Integrated analysis of water parameters and bioassays represents an essential approach to evaluating aquatic resource quality. This study aimed to assess water quality by microbiological and physicochemical parameters as well as the toxicological effects of water samples on the Ames test and Caenorhabditis elegans model. Samples were collected during (collection 1) and after (collection 2) pesticide application in the upper (S1), middle (S2), and lower (S3) sections of the Rolante River, southern Brazil. Metals were determined by GFAAS and pesticides by UPLC-MS/MS. Bioassays using the Ames test and the nematode C. elegans were performed. Levels of microbiological parameters, as well as Mn and Cu were higher than the maximum allowed limits established by legislation in collection 2 compared to collection 1. The presence of pesticide was observed in both collections; higher levels were found in collection 1. No mutagenic effect was detected. Significant inhibition of body length of C. elegans was found in collection 1 at S2 (P < 0.001) and S3 (P < 0.001) and in collection 2 at S2 (P = 0.004). Comparing the same sampling site between collections, a significant difference was found between the site of collection (F(3,6)=8.75, P = 0.01) and the time of collection (F(1,2)=28.61, P = 0.03), for the S2 and S3 samples. C. elegans model was useful for assessing surface water quality/toxicity. Results suggest that an integrated analysis for the surface water status could be beneficial for future approaches.

Toxicity of mixture of polyethylene microplastics and Up Grade® pesticide on Oreochromis niloticus juvenile: I. Hemato-biochemical and histopathological alterations

Acute toxicity experiments were conducted to determine the lethal concentration 50 (LC50) of the Up Grade®46% SL for Oreochromis niloticus. Our results showed that the 96-h LC50 value of UPGR for O. niloticus was 29.16 mg L-1. To study hemato-biochemical effects, fish were exposed for 15 days to individual UPGR at 2.916 mg L-1, individual polyethylene microplastics (PE-MPs) at 10 mg L-1, and to their combinations UPGR+PE-MPs. UPGR exposure induced significant decrease in account of red blood cells (RBCs) and white blood cells (WBCs), platelets, monocytes, neutrophils, eosinophils, and the concentrations of hemoglobin (Hb), hematocrit (Hct), and mean corpuscular hemoglobin concentration (MCHC) than other treatments, compared to the control group. Sub-acute UPGR exposure significantly increase lymphocytes, mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH), compared to the control group. In conclusion, UPGR and PE-MPs displayed antagonistic toxic effects due to maybe the sorption of UPGR onto PE-MPs.

Occurrence, fate, seasonal variability, and risk assessment of twelve triazine herbicides and eight related derivatives in source, treated, and tap water of Wuhan, Central China

Triazine herbicides have been widely used, are frequently detected in aqueous environments and soils, and can cause acute or chronic toxicity to living organisms. We collected source water samples (n = 20) originating from the Hanshui River and the Yangtze River of Wuhan section, treated water samples (n = 20), and tap water samples (n = 169) in Wuhan, Central China during 2019 for determination of twelve triazine herbicides and their eight derivatives (collectively defined as TZs) and characterizing their fate during water treatment. Eighteen of the twenty TZs were detected in the source water. Atrazine (ATZ) had the highest concentrations (median: 22.4 ng/L) in the source water samples while DACT had the highest concentrations (median: 31.4 ng/L) in the treated water. "Tryns" (ametryn, prometryn, simetryn, terbutryn) were efficiently removed by conventional water treatment, while other target analytes were not; interestingly, hydroxypropazine and prometon increased significantly accompanied by prometryn disappearance, which implicated potential transformation pathways. In addition, "tryns" might be transformed into "tons" (atraton, prometon, secbumeton, terbumeton) by ozonation. In the tap water samples, diaminochlorotriazine had the highest concentrations (median: 34.9 ng/L) among the target analytes, followed by ATZ (18.3 ng/L), hydroxyatrazine (5.17 ng/L), deethylatrazine (5.00 ng/L), hydroxypropazine (3.20 ng/L), deisopropylatrazine (2.05 ng/L), hydroxydesethylatrazine (1.68 ng/L), and others. The TZs had the highest cumulative concentration in July in the tap water samples (median: 89.7 ng/L). This study found that ozonation in combination with activated carbon was more efficient in removing triazine herbicides, although "tryns" could also be transformed during conventional treatment. Ecological risk assessment showed moderate risks posed by hydroxyterbuthylazine, prometryn, and simetryn; the Hanshui River had higher risks than the Yangtze River, and July had higher risks than February. Human exposure to the TZs via water ingestion was low compared to the reference doses. This study characterized the occurrence of some new emerging TZs in the source water, their fate during drinking water treatment, and their seasonal variability in the tap water.