Contribution of pyrethroids in large urban rivers to sediment toxicity assessed with benthic invertebrates Chironomus dilutus: A case study in South China

Abstract

The importance of pyrethroids as potential stressors to benthic organisms has gradually become evident in urban creeks; however, the occurrence and toxicity of sediment-associated pyrethroids are rarely studied in large rivers. In this context, 10 sediments from a large urban river (Guangzhou reach of the Pearl River in China) were assessed for pyrethroid occurrence and sediment toxicity to the benthic invertebrate Chironomus dilutus. One half of the sediments exhibited lethality to C. dilutus in a 10-d exposure and all surviving midges showed significant change of enzymatic activity. Moreover, mortality occurred during a 20-d exposure for all the sediments, in accordance with the high hazard quotients to benthic species estimated from pyrethroid residues in sediment. Pyrethroids were detectable in all sediments with the concentrations ranging from 2.43 to 61.2 ng/g dry weight, and permethrin and cypermethrin dominated pyrethroid composition. Acute toxic units for pyrethroids ranged from 0.03 to 0.56 (cypermethrin accounted for 13-81%) and showed a direct relationship with sediment mortality among the midges. This is consistent with the studies on small creeks in Guangzhou in which sediment-bound cypermethrin was found as a main stressor to benthic invertebrates. Comparatively, sediment toxicity and pyrethroid residues in large rivers were significantly lower than those in nearby creeks (urban tributaries). The difference may be partially explained by differing flow rates and water-carrying capacity among waterbodies at different scales; further validation is required. Overall, extensive use of pyrethroids has caused a threat to benthic species not only in small creeks but also in large rivers. Environ Toxicol Chem 2017;36:3367-3375. © 2017 SETAC.

Where has the pollution gone? A survey of organic contaminants in Ho Chi Minh city / Saigon River (Vietnam) bed sediments

“…Measured concentrations of l-cyhalothrin were close to, or largely exceeded the proposed sediment quality guideline (Ineris) of 1.05 ng g -1 , and similar to levels causing adverse effects to Chironomus dilutus larvae in sediments from Pearl River tributaries in China (Cheng et al, 2017). Cypermethrin, another pyrethroid for which no guideline could be identified, was measured at the same canal sites at (14.8 and 155 ng g -1 ).…”

Exposure and potential effects of pesticides and pharmaceuticals in protected streams of the US National park Service southeast region

“…The detection of residential-use pesticides (single analyte concentrations up to 55.6 ng g À1 prodiamine; cumulative concentrations up 71.5 ng g À1 ) in CHAT sediment samples is consistent with their hydrophobic character and resultant tendency to partition to sediment and with the predominantly residential land use and general lack of riparian buffers within the CHAT study reach. Notably, the toxicity of bifenthrin and fipronil sulfone to stream macroinvertebrates is well established (Cheng et al, 2017;Nowell et al, 2016;Rogers et al, 2016;Weston and Lydy, 2014) and both were observed in all downstream CHAT locations at sediment concentrations ranging 287-393 ng g À1 organic carbon (OC) and 16-79 ng g À1 OC, respectively. Multiple exceedances of the bifenthrin Threshold Effect Benchmark (TEB) of 170 ng g À1 OC for Hyalella azteca and the fipronil sulfone TEB of 26 ng g À1 OC for Chironomus species (Nowell et al, 2016) raise concerns for toxic effects to benthic organisms in the CHAT system.…”

Fate of Pyrethroids in Freshwater and Marine Environments

“…Sediment toxicities toward the benthic amphipod Hyalella azteca, toward the cladoceran Ceriodaphnia dubia, and toward the midge of the Diptera Chironus dilutus are common tools to survey environmental quality of freshwater sediments. When pesticides are also measured, it allows to identify which toxicant causes the observed impairment [11,38,49,59].…”

“…Deltamethrin was only detected once in this study but at very high levels from an undetermined source. In Southern China, cypermethrin, cyhalothrin, permethrin, and deltamethrin dominate over other pyrethroids in sediments of the Pearl River; their concentrations may reach notably high values in small creek sediments collected upstream in the river [49]. Cypermethrin and permethrin also dominate in sediments from an urban creek, close to Guangzhou (Southern China, [25,61]).…”