Resampling the bioconcentration factors data from Japan's chemical substances control law database to simulate and evaluate the bioconcentration factors derived from minimized aqueous exposure tests

Abstract

Existing standard bioconcentration tests (e.g., the Organization for Economic Cooperation and Development [OECD] test guideline 305) require large numbers of test animals and resources. The minimized aqueous exposure test is a new approach based on the standard bioconcentration test but allows estimation of bioconcentration factor (BCF) by minimized sampling of the test fish. The authors collected BCF data (298 curves from 155 chemicals, using common carp as test species) from Japan's Chemical Substances Control Law database and resampled the data to simulate the calculation of BCF that would be obtained if studies had been designed to obtain kinetic BCF derived from minimized aqueous exposure tests (BCF(km)). The correlation was high (r(2) = 0.967) between BCF derived from standard bioconcentration tests (BCF(full)) and BCF(km). The average value of the BCF(full) to BCF(km) ratio (BCF(full):BCF(km)) was 1.04 and ranged from 0.54 to 1.93, the 5th and 95th percentiles being 0.74 and 1.45, respectively. The results based on the 5th and 95th percentiles of the BCF(full):BCF(km) ratio suggest that BCF(full) 2,000 corresponds to BCF(km) 1,400 to 2,700, whereas BCF(full) 5,000 corresponds to BCF(km) 3,400 to 6,800. The authors also emphasize that the standard bioconcentration test should be performed when the resulting BCF(km) is in the region of regulatory concern.