[A case-control study on correlation of pesticide exposure with childhood acute leukemia]

To evaluate the correlation of pesticide exposure with childhood acute leukemia.

An exploratory case-control study was conducted among childhood acute leukemia patients under 15 years old in Shanghai, China. From January 1st, 2006 to December 31st, 2008, a total of 80 newly diagnosed acute leukemia patients were recruited from Shanghai Children's Medical Center for the case group. Another 96 age-matched patients who visited the hospital for health examination, pediatric treatment or osteological therapy excluding hematological system diseases and neoplastic disease, were recruited for the control group. A questionnaire survey was conducted in both groups; and a 30 - 40 ml random urine sample was collected from each participant. Five types of organophosphorus pesticide metabolites was then detected among the samples, using Gas Chromatography with Flame Spectrophotometry.

According to result of the questionnaire survey, more participants (55.0% (44/80)) in case group than in the control group (33.3% (32/96)) reported using mosquitocidal, which might increase the risk of childhood acute leukemia (OR = 2.444; 95%CI: 1.326 - 4.506). At the same time, the detection showed that the concentration (median) of organophosphate metabolites diethyl phosphate, dimethyl phosphate, dimethyl thiophosphate, diethyl thiophosphate and diethyl dithiophosphate in case group were 0.0682, 0.0082, 0.0183, 0.0233, 0.4259 µg/g Cr, which were all significantly higher than in control group (0.0865, 0.0025, 0.0112, 0.0123, 0.1207 µg/g Cr) except the concentration of diethyl phosphate (Z = -1.081, P = 0.279). The difference showed statistical significance (Z = -5.752, -2.800, -3.316, -8.120, P < 0.05).

Pesticide exposure may be one of the risk factors for childhood acute leukemia.