In vitro bioassays to assess drinking water quality

Abstract

In vitro assays indicative of different stages of cellular toxicity pathways have been applied to both source water and drinking water. The majority of studies showed a decrease in receptor-mediated effects after drinking water treatment due to the removal of micropollutants, while reactive toxicity typically increased after chlorination due to the formation of disinfection byproducts. Using both chemical analysis and bioanalysis, iceberg modelling can be applied to determine which chemicals are contributing to the observed effect, though one limitation is that typical sample pretreatment for bioanalysis fails to capture volatile chemicals. Bioassays are increasingly sensitive and effects can be detected in clean samples, thus effect-based trigger values can be applied to determine whether an effect in drinking water is acceptable.

Mixture effects of drinking water disinfection by-products: implications for risk assessment

“…Some of the known DBPs have been characterized by various in vitro bioassays [12][13][14] and such tools have also been applied to evaluate drinking water quality. 15 Given that more than 50% of total organic halogens are unknown, 16,17 and that there is additionally a diverse set of unknown non-halogenated compounds formed during disinfection, 18 it seems plausible that unknown DBPs contribute to adverse health effects. 10 Unknown DBPs occur-most likely-at low concentrations and thus single DBPs would have to have an extreme potency if they were to close the gap between toxicological risk assessment estimates and epidemiologic estimates.…”

Glass-bottled drinking water: a time capsule to study the historic presence of hazardous chemicals using effect-based methods

“…It should, however, be noted that the estrogenic activities observed in these samples are all considerably below this benchmark value of 1 ng E2/L. Previous studies of estrogenic activity in drinking water, using different bioassays based on mammalian cells, have reported BEQ values in the range of 0.01-5 ng E2eq/L [14][15][16][17][18][19][20]. Effect-based trigger values for estrogenic activities in drinking water in the range 0.1-3.8 ng E2eq/L have been proposed [11,15,21,22].…”

Evaluation of reverse osmosis drinking water treatment of riverbank filtrate using bioanalytical tools and non-target screening

“…the cytochrome P450, that can convert AhR ligands to reactive intermediates. 56 Further details including the procedure adopted for the AhR assay can be found in the literature. 49,54 The second bioassay to assess the xenobiotic metabolism was based on the human cell line HEK 293H expressing the peroxisome proliferator-activated receptor gamma (PPARγ-GeneBLAzer) with a reporter gene encoding for β-lactamase and followed a previously described procedure.…”