Variation, correlation, and toxicity of phenolic endocrine-disrupting compounds in surface water

Abstract

This study investigated the variation in toxicity of phenolic endocrine-disrupting compounds (EDCs) and determined the correlation between their concentrations. All twenty-four samples acquired from a polluted river contained five phenolic EDCs. The EDC nonylphenol (NP) concentration was found to be the highest (4.26 ± 2.74 μg/L) in the river water. In addition the concentrations of nonylphenol diethoxylate, (NP₂EO), octylphenol (OP), nonylphenol monoethoxylate (NP₁EO), and bisphenol A (BPA) were 1.58 ± 1.37 μg/L; 2.90 ± 2.77 μg/L; 2.89 ± 2.15 μg/L; and 2.25 ± 0.96 μg/L, respectively. Concentrations of NP, NP₁EO, and OP were significantly greater in the daytime than in the nighttime samples. Furthermore, concentrations of NP, NP₁EO, and NP₂EO showed a strong correlation due to similar parent compounds while BPA and OP did not. NP₁EO had the highest risk to aquatic organisms (hazard quotient, HQ = 26.3) and BPA the lowest (HQ = 2.24).The accumulative HQ sum (hazard index, HI) was 81.3 within all the samples. The HI was 110.3 in the daytime samples. This was 97% higher than in the nighttime HI (56.3), which suggested daytime anthropogenic discharges were an important source of toxicity to aquatic organisms.

Keywords:

• Alkylphenolic ethoxylate
• endocrine-disrupting compound
• bisphenol A
• correlation
• toxicity
• variation

Acknowledgment

This research was supported by the National Science Council, Taiwan, and grant number NSC95-2211-E-020-026.

Notes

∗Standard deviation.

∗LN: Lognormal distribution (mean, standard deviation), shift indicate mean value shift from zero for optimal fitting.

∗∗N: Normal distribution (mean, standard deviation).