Eco-Toxicity Evaluation Of Pesticides Pentachlorophenol (PCP) To Soil Fauna And Flora

Pentachlorophenol (PCP) is a kind of environmental pollutant with high risk and is also a kind of persistent organic pollutants (POPs), which can cause cancer, monstrosity and mutation. PCP is stable relatively and easy to be enriched in plants and animals. PCP can inhibit oxidative phosphorylation in the biological metabolic process. It can lead to the damage of animals'lungs, livers, kidneys and nervous systems and so on.There are few reports about eco-toxicity evaluations of PCP to plants and animals in soil at present.The current study selectes several common crops to evaluate the inhibitory effects of PCP on seed germination and root elongation, the genotoxicity effect of PCP on crops by use of the micronucleus test, the acute toxicity of PCP to Eisenia foetida at the individual level, as well as the genetic toxicity of PCP on the DNA damage of Eisenia foetidas at the molecular level by Comet assay (Single-cell gel electrophoresis, SCGE). The results were as follows:1. PCP can inhibit crop seed germination and root elongation.The germination rate and PCP concentration are negative correlation. The hemi-inhibitory concentrations of PCP on different crops are as follows: Vigna radiata, 147.7 mg/L; Cucumis sativus Linn., 28.5 mg/L; Brassica chinensis Linn., 13.8 mg/L; Lactuca sativa Linn, 11.1 mg/L; Zea mays, 167.8 mg/L; Triticum aestivum Linn., 49.1 mg/L; Sorghum bicolor Moench, 37.1 mg/L; Setaria italica, 15.3 mg/L. The inhibitory effects (EC20) of PCP on the root elongation are as follows: Vigna radiata, 50.1 mg/L; Cucumis sativus Linn., 7.6 mg/L; Brassica chinensis Linn., 5.2 mg/L; Lactuca sativa Linn, 4.3 mg/L; Zea mays, 71.2 mg/L; Triticum aestivum Linn., 12.3 mg/L; Sorghum bicolor Moench, 9.8 mg/L; Setaria italica, 6.2 mg/L. It's different in the sensitivity of the germination rate of different crops to PCP. Generally, the fibrous root crops are more sensitive than the tap root crops to PCP. The germination indexes of different crops have the same concentration-gradient effects; the inhibition effect is stronger with the PCP concentration increased.2. Cell chromosomes of wheat appear chromosome aberration such as micronucleus and physical retard such as metabolite accumulation in micronucleus test by wheat root tip. The cells in the root tips of wheat treated with high concentration of PCP appear the phenomenon of double micronucleus. 3. The 24, 48 and 72 h LC₅₀ of PCP on Eisenia foetida are 67.4, 56.7, 44.8 mg/L, respectively. The main effects of PCP acute toxicity are related to the concentration and exposure time.4. The higher the PCP concentration is, the more serious the DNA damage will be under the same exposure time when tested by Comet assay. The damaged nuclei have long comet tails in the presence of high PCP concentration.