Distribution Of Chlorpyrifos Research Articles

GC-MS/MS analysis of chlorpyrifos in forensic samples with varied survival time.

Organophosphorus pesticides are extensively used in the agricultural sector to kill insects, worms, and other pests. Many people may be poisoned by chlorpyrifos either accidentally or intentionally, including accidental, suicidal, and homicidal poisoning cases in India. The effect of chlorpyrifos on human health depends on factors such as the time, amount and frequency of exposure, the individual's health, and certain environmental conditions. The main objective of this investigation is to identify the post-mortem biological sample that shows the longest detection window, enabling precise chlorpyrifos detection in cases of acute poisoning with varying survival durations. Our research focuses on the detection and distribution of chlorpyrifos in cases of acute poisoning using a simple liquid-liquid extraction and GC-MS/MS analysis. We validated the method, which proved to be effective and reliable. Upon examining various organs, we detected the presence of chlorpyrifos in the stomach tissue, liver tissue, kidney tissue, and blood samples of individuals who consumed chlorpyrifos and passed away immediately, as well as in those who survived for the first 3days following ingestion. Analysing urine, blood, and liver tissue from individuals who survived for 3days provided more precise results compared to stomach tissue. Additionally, urine samples played a crucial role in detecting chlorpyrifos in individuals who survived for 4 and 5days. A blood sample is the most suitable post-mortem biological sample for detecting chlorpyrifos in individuals who survived for a duration of 2 to 4days. This finding highlights the significance of analysing urine as a valuable sample type, particularly in determining the presence of chlorpyrifos in cases where individuals have survived for a long period of time before their demise. The experimental data and information provided in this study will serve as a valuable resource for forensic toxicologists.

A model of chlorpyrifos distribution and its biochemical effects on the liver and kidneys of rats.

This study investigated the main target sites of chlorpyrifos (CPF), its effect on biochemical indices, and the pathological changes observed in rat liver and kidney function using gas chromatography/mass spectrometry. Adult female Wistar rats (n = 12) were randomly assigned into two groups (one control and one test group; n = 6 each). The test group received CPF via oral gavage for 21 days at 5 mg/kg daily. The distribution of CPF was determined in various organs (liver, brain, heart, lung, kidney, ovary, adipose tissue, and skeletal muscle), urine and stool samples using GCMS. Approximately 6.18% of CPF was distributed in the body tissues, and the highest CPF concentration (3.80%) was found in adipose tissue. CPF also accumulated in the liver (0.29%), brain (0.22%), kidney (0.10%), and ovary (0.03%). Approximately 83.60% of CPF was detected in the urine. CPF exposure resulted in a significant increase in plasma transaminases, alkaline phosphatase, and total bilirubin levels, a significant reduction in total protein levels and an altered lipid profile. Oxidative stress due to CPF administration was also evidenced by a significant increase in liver malondialdehyde levels. The detrimental effects of CPF on kidney function consisted of a significant increase in plasma urea and creatinine levels. Liver and kidney histology confirmed the observed biochemical changes. In conclusion, CPF bioaccumulates over time and exerts toxic effects on animals.

Dissipation and distribution of chlorpyrifos in selected vegetables through foliage and root uptake.

Dissipation, distribution and uptake pathways of chlorpyrifos were investigated in pakchoi (Brassica chinensis L.) and lettuce (Lactuca sativa) with foliage treatments under a greenhouse trial and root treatments under a hydroponic experiment. The dissipation trends were similar for chlorpyrifos in pakchoi and lettuce with different treatments. More than 94% of chlorpyrifos was degraded in the samples for both of the vegetables 21 days after the foliage treatments. For the root treatment, the dissipation rate of chlorpyrifos in pakchoi and lettuce at the low concentration was greater than 93%, however, for the high concentrations, the dissipation rates were all under 90%. Both shoots and roots of the vegetables were able to absorb chlorpyrifos from the environment and distribute it inside the plants. Root concentration factor (RCF) values at different concentrations with the hydroponic experiment ranged from 5 to 39 for pakchoi, and from 14 to 35 for lettuce. The translocation factor (TF) representing the capability of the vegetables to translocate contaminants was significantly different for pakchoi and lettuce with foliage and root treatments. The values of TF with foliage treatments ranged from 0.003 to 0.22 for pakchoi, and from 0.032 to 1.63 for lettuce. The values of TF with root treatments ranged from 0.01 to 0.17 for pakchoi, and from 0.003 to 0.23 for lettuce. Significant difference of TF was found between pakchoi and lettuce with foliage treatments, and at high concentrations (10 and 50 mg L(-1)) with root treatments as well. However, there was no significant difference of TF between pakchoi and lettuce at 1 mg L(-1) with root treatment.

Time-dependent movement and distribution of chlorpyrifos and its metabolism in bamboo forest under soil surface mulching.

The dissipation and distribution of chlorpyrifos (CHP) granule formulation in bamboo forest under soil surface mulching conditions (CP) and noncovered cultivation conditions (NCP) from soil to product were investigated. In the CP treatment, the CHP granule with slow-release effect leached from the topsoil to the subsoil. Conversely, the CHP was fixed in the topsoil (0-5 cm layer) in the NCP treatment, and no obvious leaching effect could be observed. The residue of CHP could be found in bamboo shoots from CP treatment, mainly at the bottom part (5 cm length). CHP could be degraded into 3,5,6-trichloro-2-pyridinol (TCP) in the soil and bamboo shoots. In addition, the straw used as the mulching material with higher OM and pH had some regulatory role in changing the pH and OM characteristics of the soil. Thus the straw could indirectly affect the adsorption and degradation behavior of CHP and TCP in the soil.

Exposure to Chlorpyrifos in Gaseous and Particulate Form in Greenhouses: A Pilot Study

Phase distribution of airborne chemicals is important because intake and uptake mechanisms of each phase are different. The phase distribution and concentrations are needed to determine strategies of exposure assessment, hazard control, and worker protection. However, procedures for establishing phase distribution and concentration have not been standardized. The objective of this study was to compare measurements of an airborne semivolatile pesticide (chlorpyrifos) by phase using two different procedures. Six pesticide applications in two facilities were studied and at each site, samples were collected for three time slots: T1, the first 1 or 2 hr after the commencement of application; T2, a 6-hr period immediately following T1; and T3, a 6-hr period after the required re-entry interval (24 hr for chlorpyrifos).Two phase-separating devices were co-located at the center of each greenhouse: semivolatile aerosol dichotomous sampler (SADS) using flow rates of 1.8 l.min−1 and 0.2 l.min−1, corresponding to a total inlet flow rate of 2.0 l.min−1 with a vapor phase flow fraction of 0.1; and an electrostatic precipitator (ESP), along with a standard OVS XAD-2 tube. Chlorpyrifos in vapor and particulate form in a SADS sampling train and that in vapor form in an ESP sampling train were collected in OVS tubes. Chlorpyrifos in particulate form in the ESP setting would have been collected on aluminum substrate. However, no chlorpyrifos in particulate form was recovered from the ESP. Overall (vapor plus particle) concentrations measured by OVS ranged 11.7 – 186.6 μg/m3 at T1 and decreased on average 77.1% and 98.9% at T2 and T3, respectively. Overall concentrations measured by SADS were 66.6%, 72.7%, and 102% of those measured by OVS on average at T1, T2, and T3, respectively. Particle fractions from the overall concentrations measured by SADS were 60.0%, 49.2%, and 13.8%, respectively, for T1, T2, and T3. SADS gives better guidance on the distribution of chlorpyrifos than does the ESP, although the accuracy of the concentration distribution cannot be verified in the absence of a standardized procedure for determining phase division.

Chlorpyrifos Accumulation Patterns for Child-Accessible Surfaces and Objects and Urinary Metabolite Excretion by Children for 2 Weeks after Crack-and-Crevice Application

The Children’s Post-Pesticide Application Exposure Study (CPPAES) was conducted to look at the distribution of chlorpyrifos within a home environment for 2 weeks after a routine professional crack-and-crevice application and to determine the amount of the chlorpyrifos that is absorbed by a child living within the home. Ten residential homes with a 2- to 5-year-old child in each were selected for study, and the homes were treated with chlorpyrifos. Pesticide measurements were made from the indoor air, indoor surfaces, and plush toys. In addition, periodic morning urine samples were collected from each of the children throughout the 2-week period. We analyzed the urine samples for 3,5,6-trichloropyridinol, the primary urinary metabolite of chlorpyrifos, and used the results to estimate the children’s absorbed dose. Average chlorpyrifos levels in the indoor air and surfaces were 26 (pretreatment)/120 (posttreatment) ng/m3 and 0.48 (pretreatment)/2.8 (posttreatment) ng/cm2, respectively, reaching peak levels between days 0 and 2; subsequently, concentrations decreased throughout the 2-week period. Chlorpyrifos in/on the plush toys ranged from 7.3 to 1,949 ng/toy postapplication, with concentrations increasing throughout the 2-week period, demonstrating a cumulative adsorption/absorption process indoors. The daily amount of chlorpyrifos estimated to be absorbed by the CPPAES children postapplication ranged from 0.04 to 4.8 μg/kg/day. During the 2 weeks after the crack-and-crevice application, there was no significant increase in the amount of chlorpyrifos absorbed by the CPPAES children.

Bioaccumulation, Elimination, and Tissue Distribution of Chlorpyrifos by Red Hybrid Tilapia in Fresh and Brackish Waters

Bioaccumulation, degradation, elimination and tissue partitioning of chlorpyrifos (Dursban 25E) was studied under static conditions for 3-4 days, in fresh (FW) and brackish (BW) waters by two methods: in the renewal method, fish were transferred every 24h to FW or BW aquaria containing 0.05 mg l−1 of the insecticide; in the spiking method, the original concentration of 0.005 mg l−1 was spiked every 8h. Samples of fish and water were collected at regular intervals and residues determined gas chromatographically. In the renewal experiments with 0.05mg l−1, bioconcentration reached its peak within 8h of exposure in FW (1.25 mg l−1) and within 1h in BW (0.95 mg g−1); in spiking experiments with 0.005 mg l−1, these peaks were attained in 48 h in FW (3.8 mg g−1) and 8-24 h in BW (1.67 mg g−1). Thereafter, the concentrations declined. The concentrations of an unidentified metabolite were generally but not always correlated with that of the parent compound. Upon exposure of contaminated fish to uncontaminated waters, 72% was eliminated within the first 12 h and 4% later in 60 h in FW, and only 23% in 1 h and another 21% in the following 60 h in BW. Concentration of the metabolite was very high during the elimination. In the renewal experiment with 0.05 mg l−1 of chlorpyrifos, tissue distribution was much higher in FW than in BW, while the reverse was true in spiking experiments with 0.005 mg l−1 of the chemical. Testis, heart and brain had the highest levels of residues, followed by ovaries and other tissues.

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.