Chlorpyrifos In Air Research Articles

Pyrimethanil and chlorpyrifos air concentrations and pregnant women's urinary metabolites in the Infants' Environmental Health Study (ISA), Costa Rica.

Only few studies have compared environmental pesticide air concentrations with specific urinary metabolites to evaluate pathways of exposure. Therefore, we compared pyrimethanil and chlorpyrifos concentrations in air with urinary 4-hydroxypyrimethanil (OHP, metabolite of pyrimethanil) and 3,5,6-trichloro-2-pyridinol (TCPy, metabolite of chlorpyrifos) among pregnant women from the Infant's Environmental Health Study (ISA) in Matina County, Costa Rica. During pregnancy, we obtained repeat urinary samples from 448 women enrolled in the ISA study. We extrapolated pyrimethanil and chlorpyrifos concentrations measured with passive air samplers (PAS) (n=48, from 12 schools), across space and time using a Bayesian spatiotemporal model. We subsequently compared these concentrationswith urinary OHP and TCPy in 915 samples from 448 women, usingseparatemixed models andconsidering several covariables. A 10% increase in air pyrimethanil (ng/m3) was associated with a 5.7% (95% confidence interval (CI 4.6, 6.8) increase in OHP (μg/L). Women living further from banana plantations had lower OHP: -0.7% (95% CI -1.2, -0.3) for each 10% increase in distance (meters) as well as women who ate rice and beans ≥15 times a week -23% (95% CI -38, -4). In addition, each 1ng/m3 increase in chlorpyrifos in air was associated with a 1.5% (95% CI 0.2, 2.8) increase in TCPy (μg/L), and women working in agriculture tended to have increased TCPy (21%, 95% CI -2, 49). The Bayesian spatiotemporal models were useful to estimate pyrimethanil and chlorpyrifos air concentrations across space and time. Our results suggest inhalation of pyrimethanil and chlorpyrifos is a pathway of environmental exposure. PAS seems a useful technique to monitor environmental current-use pesticide exposures. For future studies, we recommend increasing the number of locations of environmental air measurements, obtaining all air and urine measurements during the same month, and, ideally, including dermal exposure estimates as well.

Environmental pesticide concentrations in air and pregnant women’s urinary pesticide metabolites in the Infants’ Environmental Health Study (ISA)

BACKGROUND AND AIM: We evaluated associations between environmental pesticide concentrations in air and specific urinary pesticide metabolites among pregnant women from the Infants' Environmental Health Study (ISA) in Matina County, Costa Rica. METHODS: We used a Bayesian spatiotemporal model to extrapolate concentrations of the fungicide pyrimethanil and the insecticide chlorpyrifos measured with polyurethane foam passive air samplers (n=48, from 12 schools) across space and time. Using mixed models, we compared them with urinary specific-gravity corrected pesticide metabolite concentrations: 4-hydroxypyrimethanil (OHP, metabolite of pyrimethanil) and 3,5,6-trichloro-2-pyridinol (TCPy, metabolite of chlorpyrifos), repeatedly obtained among 451 pregnant women from the ISA Study (n=951). Pyrimethanil in air, OHP, and TCPy were log-transformed prior to statistical analysis to normalize residuals of models. We considered several covariables. RESULTS:Median (p10-p90) concentrations were: pyrimethanil = 1.33 (0.27-17.0) ng/m3, chlorpyrifos = 15.62 (4.38 - 24.19) ng/m3, OHP = 0.39 (0.06- 2.75) ug/L, and TCPy = 1.63 (0.75-4.27) µg/L. A 10% increase in pyrimethanil in air was associated with a 5.7% (95% CI 4.6, 6.8) increase in urinary OHP (μg/L), women who lived near banana plantations had higher OHP, whilst frequent consumption of rice and beans was associated with lower OHP. In addition, each 1 ng/m3 increase in chlorpyrifos in air was associated with a 1.5% increase in TCPy (μg/L), and women who worked in agriculture tended to have higher TCPy. CONCLUSIONS:Despite the limitations of having limited data on pesticide air concentrations in space and time, and biomonitoring of pesticides with short half-lives, the results of this study indicate environmental air concentrations of pyrimethanil and chlorpyrifos explained to some extent internal pesticide metabolite concentrations in pregnant women. Our results suggest that inhalation of these pesticides is one of the pathways of environmental exposure. Passive air sampling of current-use pesticides seems a promising method to monitor environmental pesticide exposure. KEYWORDS: passive air sampling, pesticides, environmental exposure, biomonitoring

Detection of chlorpyrifos in air of workplace with HPLC

To establish the method of detecting the concentrations of chlorpyrifos in air of workplace with high performance liquid chromatographic (HPLC). According to standards of methods for determining the chemical substances in workplace air, chlorpyrifos in the air was collected by silicone tube, then dissolved by acetonitrile and determined by high performance liquid chromatography with UV-detector. There was a linear relationship within the range of 0 ∼ 10.0 µg/ml, and regression equation was y = 5206.1x - 104.7, correlation coefficient was 0.9999, the detection limit was 0.006 µg/ml. The lowest detected concentration was 0.001 mg/m(3) (sampling volume 4.5 L). The average recoveries was 98.3% ∼ 102.5%. The within-run precision was 1.96% ∼ 4.39%, the between-run precision was 2.76% ∼ 5.87%. The desorption efficiencies were 99.0% ∼ 103.3% and the sampling efficiencies were 94%. The samples in silicone tube could be stored for 15 days at room temperature. The present method could meet with the requirements of Guide for establishing occupational health standards-Part 4 Determination methods of air chemicals in workplace and be feasible for determination of chlorpyrifos in workplace air.

Gas chromatography in determination of chlorpyrifos in air of working places

目的 建立工作场所空气中毒死蜱的溶剂解吸气相色谱测定方法.方法 采用硅胶管吸附空气中的毒死蜱,用90%甲苯和10%丙酮的混合液解吸后用带火焰光度检测器(FPD)的毛细管气相色谱法测定.结果 空气中毒死蜱浓度在0.22～14.22 mg/m3(以采集4.5 L空气样品计,相当于毒死蜱标准溶液在1-64μg/ml)时,回归方程Y=612.82X-60.59,相关系数r=0.9999,检出限为0.06 mg/m3.平均解吸效率89.67%,采样效率94.0%,样品在室温下至少可以保存15 d.结论 该方法适用于工作场所空气中毒死蜱浓度的测定。

Sources of Chlorpyrifos and Dacthal to a Small Canadian Prairie Watershed

Atmospheric deposition and air−water exchange of two semivolatile pesticides, Dacthal and chlorpyrifos, were compared in a small agricultural watershed in southern Manitoba, Canada, between 1994 and 1996. Dacthal was not used in the watershed nor in the surrounding region. Dacthal concentrations were derived from long-range transport and deposition processes and were lower than those of chlorpyrifos, which was applied locally each year of the study. Maximum concentrations of chlorpyrifos in air (103 ng/m3), precipitation (38 ng/L), and creek water (105 ng/L) were observed during local application periods. The highest Dacthal concentrations (4 ng/L) observed in precipitation occurred during intervals when its use in the U.S. was expected, although a seasonal relationship was not established. Precipitation and gas exchange across the air−water boundary were important pathways of movement for both chlorpyrifos and Dacthal. A net volatilization flux from the entire creek surface was observed for chlorpyrifos ...

Determination of chlorpyrifos in air, leaves and soil from a greenhouse by gas-chromatography with nitrogen–phosphorus detection, high-performance liquid chromatography and capillary electrophoresis

Chlorpyrifos was determined in air, leaves and soil in a greenhouse in order to establish performance differences between gas-chromatography with nitrogen–phosphorus detection (GC–NPD) and high-performance liquid chromatographic and capillary electrophoretic methods and to assess the farm workers' risk of overexposure due to air exposure and/or skin contact with this compound. Results obtained indicate that the three analytical techniques, with the specific procedures described, can be used, although only GC–NPD provides an operative limit of detection in air. Chlorpyrifos levels in air are dependent on time and greenhouse ventilation, whereas it remains for a long time on leaf surfaces and soil. As a consequence, specific instructions can be established for farm workers in order to avoid skin and respiratory exposure to chlorpyrifos.

Fate of Summertime Airborne Organophosphate Pesticide Residues in the Sierra Nevada Mountains

AbstractThis study examines the processes of dilution, degradation, and sorption to plant foliage of organophosphate (OP) pesticides during the summertime in an air corridor originating in the southern Central Valley of California and moving into the nearby Sierra Nevada mountains. Residues of chlorpyrifos, methidathion, and their oxons were examined in air and pine needles at three sites in the southern Sierra to delineate the role these processes play in the atmospheric fate of these residues. At the site closest to the Central Valley, we found relatively high levels of parent OPs and oxons in needle and air samples. At higher elevations needles contained lesser amounts of OP residues and at lower frequency, while air primarily contained the oxon form. With increasing elevation the ratio of thion to oxon form of chlorpyrifos in air decreased from 1.85 to 0.46 indicating that atmospheric oxidation was occuring. Based on the amounts of foliar deposition found, we estimate that during summer months nearly 16 kg of chlorpyrifos and its oxon may enter Sequoia National Park plant foliage. We deduce that for airborne OP insecticides, foliar deposition is a significant summertime fate process, along with atmospheric degradation and dilution.

Distribution of chlorpyrifos in air and on surfaces following crack and crevice application to rooms

Measureable levels of chlorpyrifos were seen in air and on horizontal and vertical surfaces over an 84-day sampling period following application by two different methods. Pressurized aerosol applications had the highest airborne levels over the 84-day sampling period, and movement into adjacent, nontreated rooms was seen 7 days after application. Highest surface residues found were located at floor/wall interfaces and were due probably as a result of splash or overspray around treated areas. Residue levels from desk sides were very low and all surface residues were highly variable. One could not predict what surface levels would be based upon airborne concentrations.