Toxicity of chlorinated benzenes to marine algae

Growth ofChlorella marine, Nannochloropsis oculata, Pyramidomonas sp.,Platymonas subcordiformis andPhaeodactylum tricornutum exposed to monochlorobenzene (MCB), 1,2-dichlorobenzene (1,2-DCB), 1, 2, 3, 4-tetrachlorobenzene (1, 2, 3, 4-TeCB) and pentachlorobenzene (PeCB) was tested. Tests of 72 h-EC50 values showed that the toxicity ranged in the order: MCB<1,2-DCB<1,2,3,4-TeCB<PeCB, and that toxicity of chlorinated benzene (CB) alone to marine algae was almost in the order:Pyramidomonas sp. <Platymonas subcordiformis < Nannochloropsis oculata < Chlorella marine < Phaeodactylum tricomutum. Study of the QSAR (Quantitative Structure-Activity Relationship) betweenKOW and toxicity of CBs to marine algae showed good relationships between −logEC50 and logKOW.