Effects of single and mixed estrogens on single and combined cultures of D. subspicatus and P. subcapitata.
This paper investigates the effect of estrone (E1), 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) individually and mixed at equal proportions (1:1:1) on Desmodesmus subspicatus and Pseudokirchneriella subcapitata in single and combined cultures (S+) at different exposure times based on algal growth (in vivo chlorophyll fluorescence and cell counting) and coenobium formation. EE2 and E2 were more toxic to individual and combined (S+) cultures than was E1. The frequency of coenobium formation by D. subspicatus increased significantly for all estrogens and all concentrations. After 96 h, D. subspicatus prevailed in S+. The results of the exposure to E+ suggested a less-than-additive effect on D. subspicatus and S+ and additive effect on P. subcapitata. Toxic effects occurred for both species exposed to E+ with individual estrogen concentrations below the NOEC of each species. Assays must include changes in response due to the exposure of more than one species to more than one estrogen.
Department of Sanitary and Environmental Engineering, Rio de Janeiro State University-UERJ, Rua São Francisco Xavier, 524, sl 5024E, Maracanã, Rio de Janeiro, RJ, CEP 20550-900, Brazil, andre@andresalomao.com.
André Luís de Sá
AL
Salomão
Sanye
S
Soroldoni
Marcia
M
Marques
William
W
Hogland
Daniele Maia
DM
Bila
D000460:Chlorophyta / Q000187:drug effects* / Q000502:physiology; D004958:Estradiol / Q000633:toxicity*; D004967:Estrogens / Q000633:toxicity*; D004970:Estrone / Q000633:toxicity*; D004997:Ethinyl Estradiol / Q000633:toxicity*
D004967:Estrogens; D004970:Estrone; D004997:Ethinyl Estradiol; D004958:Estradiol