Exposures of children to organophosphate pesticides and their potential adverse health effects.

159

153

Urinary dialkylphosphate (DAP) metabolites have been used to estimate human exposure to organophosphorus pesticides. We developed a method for quantifying the six DAP urinary metabolites of at least 28 organophosphorus pesticides using lyophilization and chemical derivatization followed by analysis using isotope-dilution gas chromatography-tandem mass spectrometry (GC-MS/MS). Urine samples were spiked with stable isotope analogues of the DAPs and the water was removed from the samples using a lyophilizer. The dried residue was dissolved in acetonitrile and diethyl ether, and the DAPs were chemically derivatized to their respective chloropropyl phosphate esters. The chloropropyl phosphate esters were concentrated, and analyzed using GC-MS/MS. The limits of detection of the method were in the low mg/l (parts per billion) to mid pg/ml range (parts per trillion) with coefficients of variation of 7-14%. The use of stable isotope analogues as internal standards for each of these metabolites allows for sample-specific adjustment for recovery and thus permits a high degree of accuracy and precision. Use of this method with approximately 1100 urine samples collected from pregnant women and children indicate that the low limits of detection allow this method to be used in general population studies.

Section: Methods Validationmentioning

confidence: 99%

Measurement of dialkyl phosphate metabolites of organophosphorus pesticides in human urine using lyophilization with gas chromatography-tandem mass spectrometry and isotope dilution quantification

Bravo

Caltabiano

Weerasekera

et al. 2004

159

153

“…A 25-item questionnaire was developed from existing instruments (Chilmoncyzk et al, 1993;American Institute of Research, 1991;Asher et al, 1995;New York City Health and Hospitals Corp., 1995;Beckett et al, 1996;Koren, 1997;Eskenazi et al, 1999;Joseph et al, 1999) and was designed to characterize symptoms, health practices, and environmental exposure factors that have been documented to be asthma triggers or suspected asthma triggers (Chilmoncyzk et al, 1993;Ingram et al, 1995;Stoddard and Miller, 1995;Beckett et al, 1996;Koren, 1997;Platts-Mills and Carter, 1997;Eskenazi et al, 1999). Parents were requested to complete the questions (in either Spanish or English) about their child's respiratory health (symptoms, diagnosis, and medications), family history of asthma, school absenteeism, potential environmental exposures in the home, insurance status, and race/ethnicity.…”

Section: Methodsmentioning

confidence: 99%

Household exposure factors, asthma, and school absenteeism in a predominantly Hispanic community

Freeman

Schneider

McGarvey

2003

The Passaic Asthma Reduction Effort (PARÉ ) used an asthma symptom and household exposure factor questionnaire to screen 4634 elementary school children over a 4-year period in Passaic, New Jersey. During the first year, an additional 240 preschool children were also screened. Overall, 16% of the school children were reported by their parents to have been diagnosed with asthma. In all, 30% of responding families claimed to have at least one family member diagnosed with asthma and this was five times more likely if the target child had asthma. Exposures consistently associated with childhood asthma diagnosis included environmental tobacco smoke (ETS), presence of dampness/mold, roaches, and furry pets in the home. Diagnosis of asthma was primarily associated with all six symptoms used in the PARÉ questionnaire, and secondarily with environmental factors. Puerto Rican and black children had the highest asthma prevalence (26% and 33%), while Mexican children had the lowest (7%). Use of medications and school absenteeism among asthmatic children were associated with wheeze and night cough, but not with any specific environmental exposure. Increased school absenteeism by children undiagnosed with asthma was associated with ETS and dampness/mold in the home. Differences in asthma diagnosis and absenteeism in response to environmental factors were found across ethnic subgroups. Getting asthmatic children on medical management protocols and providing families with education about environmental risk reduction should aid in reducing morbidity in this ethnically complex population. Such coordinated efforts offer the promise of reducing school absenteeism.

“…Application of pesticides in residential areas can pose a potential source of exposure, especially to children (Fenske et al, 1990;Gurunathan et al, 1998;Eskenazi et al, 1999). Pest control formulations sprayed indoors either directly adhere to, or are indirectly deposited on, furniture and surfaces in the home.…”

Section: Introductionmentioning

confidence: 99%

Transfer efficiencies of pesticides from household flooring surfaces to foods

Rohrer

Hieber

Melnyk

et al. 2003

The transfer of pesticides from household surfaces to foods was measured to determine the degree of excess dietary exposure that occurs when children's foods contact contaminated surfaces prior to being eaten. Three household flooring surfaces (ceramic tile, hardwood, and carpet) were contaminated with an aqueous emulsion of commercially available pesticides (diazinon, heptachlor, malathion, chlorpyrifos, isofenphos, and cis-and trans-permethrin) frequently found in residential environments. A surface wipe method, as typically used in residential exposure studies, was used to measure the pesticides available on the surfaces as a basis for calculating transfer efficiency to the foods. Three foods (apple, bologna, and cheese) routinely handled by children before eating were placed on the contaminated surfaces and transfers of pesticides were measured after 10 min contact. Other contact durations (1 and 60 min) and applying additional contact force (1500 g) to the foods were evaluated for their impact on transferred pesticides. More pesticides transferred to the foods from the hard surfaces, that is, ceramic tile and hardwood flooring, than from carpet. Mean transfer efficiencies for all pesticides to the three foods ranged from 24% to 40% from ceramic tile and 15% to 29% from hardwood, as compared to mostly non-detectable transfers from carpet. Contact duration and applied force notably increased pesticide transfer. The mean transfer efficiency for the seven pesticides increased from around 1% at 1 min to 55-83% when contact duration was increased to 60 min for the three foods contacting hardwood flooring. Mean transfer efficiency for 10-min contact increased from 15% to 70% when a 1500 g force was applied to bologna placed on hardwood flooring. Contamination of food occurs from contact with pesticide-laden surfaces, thus increasing the potential for excess dietary exposure of children.