Environmental Risk Assessment of Lead Arsenate Based on Bioassays With Eight Non-target Organisms

Abstract

Lead arsenate is one of the most employed pesticides in Peruvian agriculture. Protocols of bioassays allow us to determinate the effect of this pesticide on different biological components. The acute toxicity parameter more commonly employed is the median lethal concentration (LC50). This research aimed to evaluate the ecotoxicological effects of lead arseniate on eight non-target invertebrates. The folowing sequence in decresing acute ecotoxicity order in terms of arsenic after 48 h of exposure was found: Daphnia magna (EC50 = 3.1 mg L–1) > Trichogramma fuentesi (LC50 = 11.2 mg L–1) > Chrysoperla asoralis (LC50 = 29 mg L–1) > Trichogramma pretiosum (LC50 = 32.9 mg L–1) > Ceraeochrysa cincta (LC50 = 94.4 mg L–1) > Orius insidious (LC50 = 304 mg L–1) > Telenomus remus (LC50 = 364 mg L–1) > Heleobia cumingii (LC50 = 10,669 mg L–1). Considering eggs hatching, C. asoralis was more sensible than C. cincta. For T. pretiosum and T. fuentesi were observed effects on adult’s emergency since 160 and 800 mg As L–1, respectively. From these results, environmental risk assessment (ERA) of this insecticide was calculated. Risk quotient (RQ) indicated in all cases, that lead arseniate is highly risky to environment.