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National Cancer Institute... 1978A bioassay of technical-grade azinphosmethyl for possible carcinogenicity was conducted by administering the test chemical in feed to Osborne-Mendel rats and B6C3F1...
A bioassay of technical-grade azinphosmethyl for possible carcinogenicity was conducted by administering the test chemical in feed to Osborne-Mendel rats and B6C3F1 mice. Groups of 50 rats of each sex were administered azinphosmethyl at one of two doses for 80 weeks, then observed for 34 or 35 weeks. Time-weighted average doses of either 78 or 156 ppm were used for the males. Initial doses of 62.5 or 125 ppm used for the females were maintained throughout the bioassay. Matched controls consisted of groups of 10 untreated rats of each sex; pooled controls consisted of the matched controls combined with 95 male and 95 female untreated rats from similar bioassays of 10 other test chemicals. All surviving rats were killed at 114 or 115 weeks. Groups of 50 mice of each sex were administered azinphosmethyl at one of two doses for 80 weeks, then observed for 12 or 13 weeks. The doses were either 31.3 or 62.5 ppm for the males and either 62.5 or 125 ppm for the females. Matched controls consisted of groups of 10 untreated mice of each sex; pooled controls consisted of the matched controls combined with 130 male and 120 female untreated mice from similar bioassays of 11 other test chemicals. All surviving mice were killed at 92 or 93 weeks. High- and low-dose male rats and mice and high-dose female rats and mice had lower mean body weights than corresponding matched controls throughout the bioassay. Typical signs of organophosphate intoxication were observed in a few animals of both species, and included hyperactivity, tremors, and dyspnea. Sufficient numbers of animals were at risk in each species for development of late-appearing tumors. A great many tumors of the endocrine organs were observed in both dosed male and dosed female rats. Those of the adrenal in dosed males and females, the follicular cells of the thyroid in dosed females, the anterior pituitary in dosed males, and the parathyroid in dosed males occurred at statistically significant incidences when compared with pooled controls, but not with matched controls, and they were not considered to be related to administration of the test compound. The incidences of tumors of the pancreatic islets and of the follicular cells of the thyroid in the male rats suggest, but do not clearly implicate, azinphosmethyl as a carcinogen in these animals. In mice of each sex there were no increased incidences of tumors that could be related to administration of the test chemical. It is concluded that under the conditions of this bioassay, neoplasms of the thyroid and pancreatic islets suggest but do not provide sufficient evidence for the carcinogenicity of azinphosmethyl in male Osborne-Mendel rats. Azinphosmethyl was not shown to be carcinogenic in female Osborne-Mendel rats or in B6C3F1 mice of either sex.
PubMed: 12830228
DOI: No ID Found -
Environment International Jan 2023Pesticide exposure has been associated with adverse health effects. We evaluated relationships between proximity to agricultural insecticide applications and...
BACKGROUND
Pesticide exposure has been associated with adverse health effects. We evaluated relationships between proximity to agricultural insecticide applications and insecticides in household dust, accounting for land use and wind direction.
METHODS
We measured concentrations (ng/g) of nine insecticides in carpet-dust samples collected from 598 California homes. Using a geographic information system (GIS), we integrated the California Pesticide Use Reporting (CPUR) database to estimate agricultural use within residential buffers with radii of 0.5 to 4 km. We calculated the density of use (kg/km) during 30-, 60-, 180-, and 365-day periods prior to dust collection and evaluated relationships between three density metrics (CPUR unit-based, agricultural land area adjusted, and average daily wind direction adjusted) and dust concentrations. We modeled natural-log transformed concentrations using Tobit regression for carbaryl, chlorpyrifos, cypermethrin, diazinon, and permethrin. Odds of detection were modeled with logistic regression for azinphos-methyl, cyfluthrin, malathion, and phosmet. We adjusted for season, year, occupation, and home/garden uses.
RESULTS
Chlorpyrifos use within 1-4 km was associated with 1 to 2-times higher dust concentrations in both the 60- and 365-day periods. Carbaryl applications within 2-4 km of homes 60-days prior to dust collection were associated with 3 to 7-times higher concentrations and the 4 km trend was strongest using the wind-adjusted metric (p-trend = 0.04). For diazinon, there were 2-times higher concentrations for the 60-day metrics in the 2 km buffer and for the CPUR and wind-adjusted metrics within 4 km. Cyfluthrin, phosmet, and azinphos-methyl applications within 4 km in the prior 365-days were associated with 2-, 6-, and 3-fold higher odds of detection, respectively.
CONCLUSIONS
Agricultural use of six of the nine insecticides within 4 km is an important determinant of indoor contamination. Our findings demonstrated that GIS-based metrics for quantifying potential exposure to fugitive emissions from agriculture should incorporate tailored distances and time periods and support wind-adjustment for some, but not all insecticides.
Topics: Insecticides; Chlorpyrifos; Diazinon; Azinphosmethyl; Environmental Exposure; Phosmet; Carbaryl; Agriculture; Pesticides; Dust
PubMed: 36493610
DOI: 10.1016/j.envint.2022.107657 -
Environmental Analysis, Health and... Dec 2022The aim of the study was to assess the occurrence and distribution of organophosphate compounds residue in soil, surface water, sediment, and banana crops in Araromi...
The aim of the study was to assess the occurrence and distribution of organophosphate compounds residue in soil, surface water, sediment, and banana crops in Araromi farm settlement, Osun State, Nigeria. Organophosphate pesticide residues were determined using a gas chromatography equipped with Flame-Ionization Detection (GC-FID) in 16 soil samples from cocoa and banana farms, 6 water and sediment samples each, and 8 banana samples from 4 farms in the study site. Fourteen organophosphate compounds were detected (acephate, omethoate, dementon-s-methyl, dimethoate, tolcofos-methyl, pirimiphos-methyl, malathion, chlorpyrifos, methidathion, prothiofos, profenofos, ethion, azinphos-methyl and pyrazophos). Tolclofos-methyl, pirimiphos-methyl and prothiofos were detected in all the soil and sediment samples with concentration ranges of 1.9-12.9, 2.25-6.98 and 3.38-9.89 mg/kg respectively in soil and 8.13-9.83, 2.82-25.1 and 3.70-19.5 mg/kg respectively in sediment. Dimethoate, pirimiphos-methyl and prothiofos with concentration ranges, 0.06-0.28, 0.09-0.18 and 0.16-6.11 mg/L respectively were mostly detected in water samples while dimethoate, tolcofos-methyl, malathion, methidathion, prothiofos, ethion and azinphos-methyl compounds were detected in all the banana samples with concentration ranges, 3.40-12.0, 1.82-6.26, 5.73-9.48, 29.7-145, 8.24-20.1, 3.87-9.35 and 3.66-12.2 mg/kg respectively. The organophosphate mean residue concentrations were mostly significantly higher than the Maximum Residue Limits (MRL) at p<0.05. Across the three samples, only pirimiphos-methyl was significantly higher in water samples, omethoate in sediment; acephate, dementon-s-methyl and chlorpyrifos in banana were also not significantly higher at p<0.05. A strong positive significant correlation was observed between the organophosphate compounds in the banana and water samples (R=0.77, p=0.002) at p<0.05. The occurrence of organophosphate compounds in concentrations above MRLs may pose serious environmental and health risks.
PubMed: 36916048
DOI: 10.5620/eaht.2022035 -
Foods (Basel, Switzerland) Jun 2023Pesticides are extensively used in the cultivation and postharvest protection of citrus fruits, therefore continuous monitoring and health risk assessments of their...
Pesticides are extensively used in the cultivation and postharvest protection of citrus fruits, therefore continuous monitoring and health risk assessments of their residues are required. This study aimed to investigate the occurrence of pesticide residues on citrus fruits and to evaluate the acute and chronic risk for adults and children. The risk ranking of twenty-three detected pesticides was carried out according to a matrix ranking scheme. Multiple residues were detected in 83% of 76 analyzed samples. In addition, 28% contained pesticides at or above maximum residue levels (MRLs). The most frequently detected pesticides were imazalil, azoxystrobin, and dimethomorph. According to the risk ranking method, imazalil was classified in the high-risk group, followed by prochloraz, chlorpyrifos, azinphos-methyl, tebufenpyrad, and fenpiroximate, which were considered to pose a medium risk. The majority of detected pesticides (74%) posed a low risk. The health risk assessment indicated that imazalil and thiabendazole contribute to acute (HQa) and chronic (HQc) dietary risk, respectively. The HQc was negligible for the general population, while the HQa of imazalil and thiabendazole exceeded the acceptable level in the worst-case scenario. Cumulative chronic/acute risk (HIc/HIa) assessment showed that chronic risk was acceptable in all samples for children and adults, while the acute risk was unacceptable in 5.3% of citrus fruits for adults and 26% of citrus fruits for children. Sensitivity analyses indicated that the ingestion rate and individual body weight were the most influential risk factors.
PubMed: 37444192
DOI: 10.3390/foods12132454 -
International Journal of Hygiene and... Mar 2023Our prior work shows that azinphos-methyl pesticide exposure is associated with altered oral microbiomes in exposed farmworkers. Here we extend this analysis to show the...
Our prior work shows that azinphos-methyl pesticide exposure is associated with altered oral microbiomes in exposed farmworkers. Here we extend this analysis to show the same association pattern is also evident in their children. Oral buccal swab samples were analyzed at two time points, the apple thinning season in spring-summer 2005 for 78 children and 101 adults and the non-spray season in winter 2006 for 62 children and 82 adults. The pesticide exposure for the children were defined by the farmworker occupation of the cohabitating household adult and the blood azinphos-methyl detection of the cohabitating adult. Oral buccal swab 16S rRNA sequencing determined taxonomic microbiota proportional composition from concurrent samples from both adults and children. Analysis of the identified bacteria showed significant proportional changes for 12 of 23 common oral microbiome genera in association with azinphos-methyl detection and farmworker occupation. The most common significantly altered genera had reductions in the abundance of Streptococcus, suggesting an anti-microbial effect of the pesticide. Principal component analysis of the microbiome identified two primary clusters, with association of principal component 1 to azinphos-methyl blood detection and farmworker occupational status of the household. The children's buccal microbiota composition clustered with their household adult in ∼95% of the households. Household adult farmworker occupation and household pesticide exposure is associated with significant alterations in their children's oral microbiome composition. This suggests that parental occupational exposure and pesticide take-home exposure pathways elicit alteration of their children's microbiomes.
Topics: Adult; Humans; Child; Pesticides; Farmers; Azinphosmethyl; RNA, Ribosomal, 16S; Agriculture; Occupational Exposure; Microbiota
PubMed: 36516690
DOI: 10.1016/j.ijheh.2022.114090 -
Scientific Reports Mar 2016Robust and sensitive detection systems are a crucial asset for risk management of chemicals, which are produced in increasing number and diversity. To establish an in...
Robust and sensitive detection systems are a crucial asset for risk management of chemicals, which are produced in increasing number and diversity. To establish an in vivo biosensor system with quantitative readout for potential toxicant effects on motor function, we generated a transgenic zebrafish line TgBAC(hspb11:GFP) which expresses a GFP reporter under the control of regulatory elements of the small heat shock protein hspb11. Spatiotemporal hspb11 transgene expression in the musculature and the notochord matched closely that of endogenous hspb11 expression. Exposure to substances that interfere with motor function induced a dose-dependent increase of GFP intensity beginning at sub-micromolar concentrations, while washout of the chemicals reduced the level of hspb11 transgene expression. Simultaneously, these toxicants induced muscle hyperactivity with increased calcium spike height and frequency. The hspb11 transgene up-regulation induced by either chemicals or heat shock was eliminated after co-application of the anaesthetic MS-222. TgBAC(hspb11:GFP) zebrafish embryos provide a quantitative measure of muscle hyperactivity and represent a robust whole organism system for detecting chemicals that affect motor function.
Topics: Animals; Animals, Genetically Modified; Azinphosmethyl; Biosensing Techniques; Dose-Response Relationship, Drug; Founder Effect; Galantamine; Gene Expression Regulation; Green Fluorescent Proteins; Intracellular Signaling Peptides and Proteins; Motor Activity; Muscles; Mutant Chimeric Proteins; Notochord; Pesticides; Promoter Regions, Genetic; Propoxur; Zebrafish
PubMed: 27029555
DOI: 10.1038/srep23768 -
Frontiers in Neuroscience 2019Poisoning with organophosphorus compounds (OPCs) is a major problem worldwide. Standard therapy with atropine and established oxime-type enzyme reactivators... (Review)
Review
Poisoning with organophosphorus compounds (OPCs) is a major problem worldwide. Standard therapy with atropine and established oxime-type enzyme reactivators (pralidoxime, obidoxime) is unsatisfactory. In search of more efficacious broad-spectrum oximes, new bispyridinium (K-) oximes have been synthesized, with K027 being among the most promising. This review summarizes pharmacokinetic characteristics of K027, its toxicity and efficacy to protect from OPC toxicity and compares this oxime with another experimental bisquaternary asymmetric pyridinium aldoxime (K048) and two established oximes (pralidoxime, obidoxime). After intramuscular (i.m.) injection, K027 reaches maximum plasma concentration within ∼30 min; only ∼2% enter the brain. Its intrinsic cholinesterase inhibitory activity is low, making it relatively non-toxic. reactivation potency is high for ethyl-paraoxon-, methyl-paraoxon-, dichlorvos-, diisopropylfluorophosphate (DFP)- and tabun-inhibited cholinesterase. When administered after exposure to the same OPCs, K027 is comparable or more efficacious than pralidoxime and obidoxime. When given as a pretreatment before exposure to ethyl-paraoxon, methyl-paraoxon, DFP, or azinphos-methyl, it is superior to the Food and Drug Administration-approved compound pyridostigmine and comparable to physostigmine, which because of its entry into the brain may cause unwanted behavioral effects. Because of its low toxicity, K027 can be given in high dosages, making it a very efficacious oxime not only for postexposure treatment but also for prophylactic administration, especially when brain penetration is undesirable.
PubMed: 31191210
DOI: 10.3389/fnins.2019.00427 -
Journal of Occupational and... Dec 2018Organophosphorus pesticides (OPs) are commonly applied to agricultural crops. Families living in these communities may have higher exposure to OPs due to take home...
Organophosphorus pesticides (OPs) are commonly applied to agricultural crops. Families living in these communities may have higher exposure to OPs due to take home exposures and close proximity to agricultural fields. The objectives of this study were to measure OP concentrations in home carpet dust in agricultural and non-agricultural households and examine factors that may impact OP concentrations such as occupation, housing characteristics, and resident behaviors. Agricultural households had at least one parent who worked in agriculture during the previous 5 years. Carpet dust samples were collected at two time points from 278 households in an agricultural community located in the Pacific Northwest from 2008-2011. Samples were analyzed for four types of OPs: azinphos-methyl, phosmet, malathion, and chlorpyrifos. Overall, OP detection frequencies and concentrations were higher in agricultural households compared to non-agricultural households. Factors associated with higher OP concentrations in home carpet dust were identified and included: (1) homes with two or more agricultural workers living in the home, (2) homes located in close proximity to an agricultural field or orchard, (3) having an entry floor mat, and (4) frequently vacuuming the house. Having air conditioning in the home had a protective effect with OP concentrations. While the use of these four OPs is restricted or limited for residential use in the United States, results show that they were still found in the indoor environment. The understanding of the impact of agricultural work and other factors that elevate levels of OPs in the home is crucial to mitigating pesticide exposure in agricultural communities.
Topics: Adult; Child; Child, Preschool; Dust; Environmental Exposure; Farmers; Farms; Floors and Floorcoverings; Housing; Humans; Northwestern United States; Occupational Exposure; Organothiophosphates; Parents; Pesticide Residues
PubMed: 30138040
DOI: 10.1080/15459624.2018.1515489 -
Insects Dec 2021The codling moth, L. (Lepidoptera, Tortricidae), is a serious invasive pest of pome fruits. Currently, management mainly relies on the application of insecticides,...
The codling moth, L. (Lepidoptera, Tortricidae), is a serious invasive pest of pome fruits. Currently, management mainly relies on the application of insecticides, which have driven the development of resistance in the insect. Understanding the genetic mechanisms of insecticide resistance is of great significance for developing new pest resistance management techniques and formulating effective resistance management strategies. Using existing genome resequencing data, we performed selective sweep analysis by comparing two resistant strains and one susceptible strain of the insect pest and identified seven genes, among which, two (glycine receptor and glutamate receptor) were under strong insecticide selection, suggesting their functional importance in insecticide resistance. We also found that eight genes including , , , , and , are potentially involved in cross-resistance to azinphos-methyl and deltamethrin. Moreover, among several P450s identified as positively selected genes, , , and showed the highest expression level in larva compared to other stages tested, and also showed the highest expression level in midgut, supporting the roles they may play in insecticide metabolism. Our results provide several potential genes that can be studied further to advance understanding of complexity of insecticide resistance mechanisms in .
PubMed: 35055845
DOI: 10.3390/insects13010002 -
Environmental Health Perspectives Jun 1994Peach harvest workers were evaluated for exposure to azinphosmethyl residues by measuring foliar residues, urinary alkylphosphate metabolites, butyrylcholinesterase...
Peach harvest workers were evaluated for exposure to azinphosmethyl residues by measuring foliar residues, urinary alkylphosphate metabolites, butyrylcholinesterase (BChE), acetylcholinesterase (AChE), and dermal residues using clothing and skin washes. Workers entered orchards 51 days after application and worked in treated fields for 10 of the next 17 days. Dislodgeable foliar residues ranged from 0.82 to 1.72 microg/cm2 and did not change significantly over the study period. Combined mean dermal exposure for the 3 consecutive monitoring days was 32 mg and ranged from 17.9 to 60.5 mg. Overall mean excretion levels for the 5 monitoring days were 1.7 mg dimethylphosphate and 1.9 mg dimethlythiophosphate. There was no significant difference in BChE between the exposed harvesters and minimally exposed sorters. The exposed group had significantly lower AChE values than the sorters for 2 post-exposure blood draws by three testing methods, while no significant difference was found for the pre-exposure blood draw. The AChE values for the post-exposure blood samples for the exposed workers decreased significantly about 10-20% over the 3-week exposure period but increased or remained constant for the sorters. Urinary metabolite excretion increased with continuous exposure and was inversely correlated with both AChE and BChE but was not correlated with dermal exposure measurements. High correlations were generally observed between AChE measurements taken in the field using a new spectrophotometric kit and laboratory AChE measurements.
PubMed: 9679119
DOI: 10.1289/ehp.94102580