Spatial and temporal ecological risk assessment of unionized ammonia nitrogen in Tai Lake, China (2004-2015)

Yabing Li; Elvis Genbo Xu; Wei Liu; Yi Chen; Hongling Liu; Di Li; Zhengtao Liu; John P Giesy; Hongxia Yu

doi:10.1016/j.ecoenv.2017.02.050

Spatial and temporal ecological risk assessment of unionized ammonia nitrogen in Tai Lake, China (2004-2015)

Ecotoxicol Environ Saf. 2017 Jun:140:249-255. doi: 10.1016/j.ecoenv.2017.02.050. Epub 2017 Mar 8.

Authors

Yabing Li¹, Elvis Genbo Xu², Wei Liu³, Yi Chen³, Hongling Liu⁴, Di Li⁵, Zhengtao Liu⁶, John P Giesy⁷, Hongxia Yu¹

Affiliations

¹ State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China.
² Department of Environmental Sciences, University of California, Riverside CA92521, USA.
³ Jiangsu Provincial Academy of Environmental Sciences, Nanjing, Jiangsu 210036, China.
⁴ State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China. Electronic address: hlliu@nju.edu.cn.
⁵ State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China; Jiangsu Environmental Monitoring Center, Nanjing, Jiangsu 210036, China.
⁶ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
⁷ State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China; Toxicology Center and Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Sask. S7N 5B3, Canada; School of Biological Sciences, University of Hong Kong, SAR, China.

PMID: 28273624
DOI: 10.1016/j.ecoenv.2017.02.050

Abstract

Ammonia toxicity varies largely due to its pH- and temperature-dependent speciation (unionized ammonia nitrogen, NH₃-N). The seasonal and long-term trend of ammonia risk in ecologically significant sections of Tai Lake, China was unknown. In this study, a two-level (deterministic and quantitative) method was developed to assess the special ecological risks posed by NH₃-N at 37 sites during two seasons (February and September) of 2014 in Tai Lake. The long-term temporal (2004-2015) risk posed by NH₃-N was also assessed by comparing annual quantitative risk values (probability of exceeding acute or chronic threshold values) in three key sections of Tai Lake. The results indicated the species living in the Tai Lake were at a 0.04% and 32.45% chance of risk due to acute exposure, and a 1.97% and 92.05% chance of risk due to chronic exposure in February and September of 2014, respectively. Alarmingly, the chronic ecological risks of NH₃-N in the Lanshanzui section of the Tai Lake remained >30% from 2004 to 2011. The chronic risk of NH₃-N in all three key sections of Tai Lake started to decrease in 2011. This was likely the consequence of the control practice of eutrophication implemented in the Tai Lake. A significant decline in diversity of the benthic invertebrate community of the Tai Lake could be associated with continuous exposure to ammonia over decades given different sensitivity of taxa to ammonia. The results laid a scientific foundation for risk assessment and management of ammonia in Tai Lake, China, and the developed two-level risk assessment approach can also be applied to other similar aquatic regions.

Keywords: Ammonia; Biological indicator; Ecological risk assessment; Probabilistic.

MeSH terms

Ammonia / analysis*
Ammonia / toxicity
Animals
China
Ecology
Invertebrates / drug effects
Lakes / chemistry
Nitrogen / analysis*
Nitrogen / toxicity
Risk Assessment / methods
Water Pollutants, Chemical / analysis*
Water Pollutants, Chemical / toxicity

Substances

Water Pollutants, Chemical
Ammonia
Nitrogen