Environmental Toxicity of CWAs and Their Metabolites

This chapter reviews the environmental toxicity of CWAs and their metabolites as well as mixtures of CWAs. We used Microtox™ to generate EC50 value for 11 compounds. We observed hormetic effects for two compounds namely Triphenylarsine and Triphenylarsine oxide. None of the mixtures tested show sign of synergism. Two compounds can be characterized as very toxic as both α-chloroacetophenone (EC50 = 11.20 μg L−1) and 2-chlorovinylarsinic acid (EC50 = 31.20 μg L−1) demonstrated EC50 values below 1000 μg L−1. Several compounds can be characterized as toxic as 1,2,5-trithiepane (EC50 = 1170 μg L−1), 1,4,5-oxadithiepane (EC50 = 1700 μg L−1), phenarsazinic acid (EC50 = 5330 μg L−1) and 1,4-dithiane (EC50 = 9970 μg L−1) as these compounds demonstrated EC50 values between 1000 μg L−1 and 10,000 μg L−1. An D. magna acute LC50 for, the compound most frequently detected compound (DPA [ox]), was determined to be 100,000 μg L−1. A chronic D. magna LC5019days of 640 μg L−1 was derived for the compound. A 14-day locomotor behaviour test on adult male Zebrafish (Danio rerio) revealed altered behaviour when exposed to concentrations of 1,4,5-oxadithiepane down to 40.3 ± 2.9 μg L−1. A NOECweight and NOECmortality greater than 1533 μg L−1 was determined for 1,4,5-oxadithiepane.