ABSTRACT
Cytochrome P450 family genes (CYPs) have common polymorphisms, which are evaluated for pesticide-inducedoxidative stress susceptibility. Variant alleles in CYP enzymes may uncover susceptibility biomarkers of environmentaltoxicity. This study aims to investigate the relationship between CYP2D6 (G1934A) gene polymorphisms and chronicpesticide exposures, and to evaluate the association between CYP2D6 (G1934A) gene polymorphism on biochemicaland hematological parameters. A cross-sectional study was carried out at a health promoting hospital, Suphan Buri,Thailand. Rice farmers and a control group (n = 50 for each) were recruited and their personal data were collected. Theirblood samples were obtained by venepuncture and drawn into plain and Ethylenediaminetetraacetic acid (EDTA) tubes.Serum cholinesterase (SChE), liver function test, kidney function test, and complete blood count were assessed usingautomatic analyzers; and CYP2D6 (G1934A) genotyping was carried out by polymerase chain reaction-restrictionfragment length polymorphism (PCR-RFLP). SChE in rice farmers was significantly lower (p = 0.033), which maybe related to the use of chlorpyrifos. The genotypes were significantly different between rice farmers and the controlgroup (p = 0.0001), and the GA variant in rice farmers was more frequent. The CYP2D6 (G1934A) (rs 3892097))gene and SChE level were negatively correlated (r = −0.258, p = 0.009). However, other biochemical parameters werenot different. Blood indices, including mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV), andmean corpuscular hemoglobin concentration (MCHC), values of rice farmers were significantly lower than the controlgroup; and MCH, MCV, and MCHC values of the GA variant were also significantly lower than the wild type. The GAgenotype was associated with hematological toxicity of organophosphate metabolite in chronic exposures.
ABSTRACT
This study focused on the photocatalytic destruction of dichloromethane (DCM) in indoor air using the nano-TiO2 /LDPE composite film as an economical photocatalyst. The nano-TiO2 was dispersed in a polyethylene matrix to form composite film. The photocatalytic activity of the nano-TiO2/LDPE composite films was evaluated through the degradation of dichloromethane (DCM) under UV-C irradiance at specific wavelength of 254 nm. The percentage of nano-TiO2 contents varied from 0, 5, and 10% (wt cat./wt LDPE composite film). The results derived from the kinetic model revealed that the photocatalytic rates of 5 and 10 wt.% nano-TiO2/LDPE composite films follow the first order reaction while the rate of the film without TiO2 followed the zero order reaction. At low concentration of DCM, the rate of photocatalytic degradation of the DCM was slower than that at high DCM concentration. The 10 wt.% of TiO2 content of the nano-TiO2/LDPE composite film yielded the highest degradation efficiency of 78%, followed by the removal efficiency of 55% for the 5 wt.% of TiO2 content of the nano-TiO2/LDPE composite film. In contrast with the composite film containing nano-TiO2, the LDPE film without adding nano-TiO2 expressed the degradation efficiency of 28%.