Influence of pH on the toxicity of ionisable pharmaceuticals and personal care products to freshwater invertebrates.

TLDR: The results of this study show that pH fluctuations can have a considerable influence on toxicity thresholds, and should be taken into account for the risk assessment of ionisable pharmaceuticals and personal health-care products.

About: This article is published in Ecotoxicology and Environmental Safety.The article was published on 2020-03-15 and is currently open access. It has received 7 citations till now. The article focuses on the topics: Acute toxicity & Aquatic toxicology.

Figures

Table 1 Water content, lipid content and internal pH of the tested organisms (mean ± SD).

Table 2 EC50 values for enrofloxacin (ENR) and triclosan (TCS) on the three test invertebrate species at different pH conditions. The measured pH conditions in the test medium are provided together with the calculated fraction of neutral chemical ( N ).

Table 3 Regression coefficients (R2) and calculated Pearson correlation p-values (between brackets) of the single model fits, followed by the calculated model parameters. EC50 (neu): EC50 calculated for the neutral chemical form. EC50 (charged): EC50 calculated for the charged chemical form. EC50 (internal): EC50 calculated taking into account the internal pH. All EC50 values are in mg/L.

Fig. 1. Comparison of EC50-96 h values for enrofloxacin with the calculated parameters of Model 1, 2 and 3. Comparisons for the EC50-48 h values are provided in Fig. S1.

Fig. 2. Comparison of EC50-96 h values for triclosan with the calculated parameters of Model 1, 2 and 3. Comparisons for the EC50-48 h values are provided in Fig. S2. For G. pulex, the EC50 value for pH = 8 was not included in the modelling calculations.

Frequently asked questions

Q1. What are the contributions mentioned in the paper "Influence of ph on the toxicity of ionisable pharmaceuticals and personal care products to freshwater invertebrates" ?

In this study the authors evaluated to what extent varying pH conditions may influence the toxicity of the antibiotic enrofloxacin ( ENR ) and the personal care product ingredient triclosan ( TCS ) to three freshwater invertebrates: the ephemeropteran Cloeon dipterum, the amphipod Gammarus pulex and the snail Physella acuta. Acute toxicity tests were performed by adjusting the water pH to four nominal levels: 6. 5, 7. 0, 7. 5 and 8. 0. Furthermore, the authors tested the efficiency of three toxicity models with different assumptions regarding the uptake and toxicity potential of ionisable chemicals with the experimental data produced in this study. The results of this study show that pH fluctuations can have a considerable influence on toxicity thresholds, and should therefore be taken into account for the risk assessment of ionisable pharmaceuticals and personal health-care products.