Ecological and health risks of DDTs and HCHs in surface water from the upper reaches of the Huaihe River

Abstract

Based on the available toxicity data and the concentrations of DDTs and HCHs in surface water from the upper reaches of the Huaihe River, overlapping areas of probability density and margin of safety (MOS₁₀) were used to estimate the risk levels of DDTs and HCHs to aquatic organisms. The overlapping areas of α-HCH, γ-HCH, p,p′-DDE, p,p′-DDD, and p,p′-DDT were found to be 9.3 × 10⁻⁵, 4.6 × 10⁻³, 4.3 × 10⁻², 2.2 × 10⁻², and 4.2 × 10⁻², respectively. The risks from DDTs were higher than those from HCHs, the risk from α-HCH being the smallest. The MOS₁₀ values of α-HCH, γ-HCH, p,p′-DDE, p,p′-DDD, and p,p′-DDT were 2.6 × 10³, 97, 5.9, 15, and 8.6, respectively, i.e. greater than 1.0, indicating limited overlaps between the distributions of exposure concentrations and of toxicity data, and thus minimal ecological risk. Health risk calculations based on incremental lifetime risks for HCHs and DDTs were conducted to evaluate human cancer risk and non-carcinogenic hazard. The total cancer risks from organochlorine pesticides (OCPs) in the studied area were in the range of 10⁻⁸–10⁻⁷, lower than the baseline value of acceptable risk (10⁻⁶). Non-carcinogenic hazard indices of OCPs ranging from 10⁻⁶ to 10⁻⁵ were much lower than the threshold values (1.0). These results suggest that the water from the upper reaches of the Huaihe River does not pose any health risk for local residents using river water as a source for drinking water.

Keywords:

• DDTs
• HCHs
• ecological risk
• health risk
• surface water
• Huaihe River

Acknowledgments

This study was supported by the National Scientific Foundation of China (Grant No. 41373132), Innovation Scientists and Technicians Troop Construction Projects of Henan Province and Plan for Scientific Innovation Talent of Henan Province (134200510014) and Foundation for University Key Teacher by Henan Province (2013GGJS-059).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by the National Scientific Foundation of China [grant number 41373132], Innovation Scientists and Technicians Troop Construction Projects of Henan Province and Plan for Scientific Innovation Talent of Henan Province [grant number 134200510014] and Foundation for University Key Teacher by Henan Province [grant number 2013GGJS-059].