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D J Cai

Publications and source records attributed to D J Cai.

4 recordsLinked to original sources
PubMed2006

Comparison of the acute toxicity for gamma-cyhalothrin and lambda-cyhalothrin to zebra fish and shrimp.

Gamma-cyhalothrin 15CS (GCH) contains only the active stereoisomer of the two isomers found in lambda-cyhalothrin 25EW (LCH). GCH (0.5 x rate) provides equivalent overall insect control as LCH (1 x rate). Both formulations showed high acute toxicity to zebra fish (Brachydanio rerio H.B.) and shrimp (Macrobrachium nippoensis de Haan). The 96-h LC(50(zebra fish,GCH)) is 1.93 microg a.i/L and LC(50(zebra fish,LCH)) is 1.94 microg a.i/L. LC(50(shrimp,GCH)) is 0.28 microg a.i./L and LC(50(shrimp,LCH)) 0.04 microg a.i./L. This indicates that the toxicity to shrimp is likely stereochemistry-dependent. The fates of GCH and LCH are similar in laboratory simulated rice paddy water and their concentrations decrease rapidly, with no GCH or LCH detected after 3 or 4 days. Both are toxic to shrimp in a simulated paddy irrigation reservoir even though treated return water is diluted 5 times. No shrimp fatality is shown in the GCH-treated paddy water after a 4-day holding period, and longer than 5 days is necessary to reach a zero fatality rate for LCH. This is compatible with the 7-day water holding period considered reasonable in agricultural practice.

Animals↗
PubMed2001

Gridded usage inventories of technical hexachlorocyclohexane and lindane for China with 1/6 degrees latitude by 1/4 degrees longitude resolution.

China banned the use of technical HCH (BHC: 1,2,3,4,5,6-hexachlorocyclohexane) in 1983; lindane has been used in this country since 1991. The total production was around 4 million t for technical HCH from 1952 to 1984, and 11,400 t for lindane between 1991 and 2000. Though the total produced technical HCH was considered to be used in China, only 3,200 t of lindane were used between 1991 and 2000 with the rest for export or on unused stack. Annual usage of these two compounds was located into each province first and then broken for different crops. Inventories of gridded usage of both technical HCH and lindane with 1/6 degrees by 1/4 degrees latitude/longitude resolution have been created by different gridded cropland data sets as surrogate data. The intensive use of technical HCH on croplands was concentrated in the southeastern part of China, but the use of lindane was concentrated in the northern part of China.

Agriculture↗
PubMed1998

Technical hexachlorocyclohexane use trends in China and their impact on the environment.

Trends in production of technical HCH (BHC: 1,2,3,4,5, 6-hexachlorocyclohexane) in China have been surveyed from 1952 to 1983, when the Chinese government banned the use of this pesticide. While the total 4.46 million metric tons produced during this period make China by far the biggest producer and user of technical HCH, Japan consumed the largest accumulated average amount of this insecticide over arable land (84 t/kha for Japan versus 44 t/kha for China). The relationship between technical HCH production/usage trends and their impact on the environment has been studied. The similarity between total HCH isomer concentrations in Chinese environmental compartments in the beginning of 1980s and those in Japanese in the beginning of 1970s indicates the linkage between the average accumulated usage of technical HCH and the magnitude of contamination in the environment by this organochlorine insecticide. According to data from a national monitoring program on food contamination by organochlorine pesticides, residues of total HCH in foodstuffs in China decreased by about five times in rice, 127 times in fish, 32 times in poultry eggs, and 32 times in meat between 1978 and 1992.

Agriculture↗