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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 -
Journal of Applied Toxicology : JAT Jan 2019Organophosphorus compounds (OPCs), inhibitors of acetylcholinesterase (AChE), are useful agents as pesticides, but also represent a serious health hazard. Standard... (Review)
Review
Organophosphorus compounds (OPCs), inhibitors of acetylcholinesterase (AChE), are useful agents as pesticides, but also represent a serious health hazard. Standard therapy with atropine and established oxime-type enzyme reactivators (pralidoxime, obidoxime) is unsatisfactory. Better therapeutic results are obtained, when reversible AChE inhibitors are administered before OPC exposure. This review summarizes the history of such a pretreatment approach and sums up a set of experiments undertaken in search of compounds that are efficacious when given before a broad range of OPCs. The prophylactic efficacy of 10 known AChE inhibitors, either already used clinically for different indications (physostigmine, pyridostigmine, ranitidine, tiapride, tacrine, amiloride, metoclopramide, methylene blue) or developed for possible therapeutic use in the future (7-methoxytacrine, K-27) was compared, when administered before exposure to six chemically diverse OPCs in the same experimental setting: ethyl-paraoxon, methyl-paraoxon, diisopropylfluorophosphate, terbufos sulfone, azinphos-methyl and dicrotophos. The experimental oxime K-27 was the most efficacious compound, affording best protection, when administered before terbufos sulfone, azinphos-methyl and dicrotophos, second best before ethyl- and methyl-paraoxon exposure and third best before diisopropylfluorophosphate administration. This ranking was similar to that of physostigmine, which was superior to the Food and Drug Administration-approved pretreatment for soman with pyridostigmine. Tiapride, amiloride, metoclopramide, methylene blue and 7-methoxytacrine did not achieve protection. No correlation was observed between the IC of the reversible AChE inhibitors and their protective efficacy. These studies indicate that K-27 can be considered a very promising broad-spectrum prophylactic agent in case of imminent organophosphate exposure, which may be related to its AChE reactivating activity rather than its AChE inhibition.
Topics: Animals; Cholinesterase Inhibitors; Humans; Models, Animal; Organophosphate Poisoning; Organophosphates; Pre-Exposure Prophylaxis
PubMed: 30027640
DOI: 10.1002/jat.3662 -
Ecotoxicology and Environmental Safety Oct 2018Organophosphate insecticides (OPs) are commonly used in Argentina and around the world for pest control in food crops. They exert their toxicity through the inhibition...
Environmental concentrations of azinphos-methyl cause different toxic effects without affecting the main target (cholinesterases) in the freshwater gastropod Biomphalaria straminea.
Organophosphate insecticides (OPs) are commonly used in Argentina and around the world for pest control in food crops. They exert their toxicity through the inhibition of the enzyme acetylcholinesterase. In the present study, we aimed to evaluate biochemical and reproductive effects in Biomphalaria straminea, a freshwater gastropod naturally distributed in Argentina, of subchronic exposures to environmental azinphos-methyl concentrations (20 and 200 µg L). For biochemical parameters, adult organisms were exposed for 14 days and the activity of cholinesterases (ChEs), carboxylesterases (CEs), glutathione S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), the production of reactive oxygen species (ROS), the total antioxidant capacity (TAC), glycogen and proteins were determined. For reproductive parameters, the egg masses of B. straminea were exposed to azinphos-methyl for one month, and the hatching time and success as well as the offspring survival were registered. We found different toxic effects elicited by the insecticide on the studied biomarkers. CEs activity was significantly inhibited while CAT and GST activities, ROS production and TAC were significantly increased, with respect to the solvent control group. ChE and SOD activities and protein and glycogen contents were not altered by azinphos-methyl. The hatching time and success were not statistically different from control. Nevertheless, the offspring survival was severely affected by the insecticide. Our results show that the primary target of the insecticide (ChE) was not inhibited but CEs, GST, CAT, ROS, TAC and offspring survival were sensitive biomarkers and valuable endpoints for subchronic toxicity assessments in this species.
Topics: Animals; Azinphosmethyl; Biomarkers; Biomphalaria; Carboxylic Ester Hydrolases; Catalase; Cholinesterases; Fresh Water; Glutathione Transferase; Insecticides; Reactive Oxygen Species; Reproduction; Superoxide Dismutase; Water Pollutants, Chemical
PubMed: 30005401
DOI: 10.1016/j.ecoenv.2018.06.091 -
Aquatic Toxicology (Amsterdam,... Jun 2018Carbamate insecticides such as carbaryl and organophosphates such as azinphos-methyl share the ability to inhibit the activity of B-esterases. This study aimed to (1)...
Carbamate insecticides such as carbaryl and organophosphates such as azinphos-methyl share the ability to inhibit the activity of B-esterases. This study aimed to (1) assess the inhibitory effects of carbaryl on B-esterase activity in soft tissues and hemolymph of Planorbarius corneus; (2) establish whether binary mixtures of carbaryl and azinphos-methyl depart or not from a model of concentration addition on the inhibition of cholinesterase activity; (3) determine the bioconcentration and elimination of the pesticides. The results showed that exposure of gastropods to increasing concentrations of carbaryl (0.1-5 mg L) for 48 h inhibited cholinesterase activity in a concentration-dependent manner, with an EC of 1.4 ± 0.3 mg L and 1.2 ± 0.1 mg L for soft tissue and hemolymph, respectively. Carboxylesterase activity, measured with the substrates p-nitrophenyl butyrate and p-nitrophenyl acetate, was between 2.3 and 25 times more sensitive to carbaryl inhibition than cholinesterase activity. Binary mixtures corresponding to 0.5 EC carbaryl + 0.5 EC azinphos-methyl and 0.75 EC carbaryl + 0.75 EC azinphos-methyl produced inhibitions of cholinesterase activity similar to those of individual pesticides, following a model of concentration addition. Bioconcentration was analyzed using a one-compartment model. The absorption kinetics (k) for both pesticides alone (1.4 mg L of carbaryl or 1.8 mg L of azinphos-methyl) or mixed (1.4 mg L of carbaryl + 1.8 mg L of azinphos-methyl) were similar. The elimination kinetics ratio (k) estimated for the pesticides alone or in the mixtures showed that carbaryl was eliminated 3.5 times faster than azinphos-methyl. These results suggest that exposure of Planorbarius corneus to binary mixtures of carbaryl and azinphos-methyl for 48 h follow a concentration addition model on inhibition of cholinesterase activity and that the pesticide mixtures do not change the toxicokinetic parameters of the parent compounds.
Topics: Animals; Azinphosmethyl; Carbaryl; Carboxylesterase; Cholinesterases; Fresh Water; Gastropoda; Hemolymph; Kinetics; Toxicokinetics; Water Pollutants, Chemical
PubMed: 29689476
DOI: 10.1016/j.aquatox.2018.04.005 -
Environmental Science and Pollution... Apr 2018Agriculture represents the second most important economic activity in the North Patagonian Region of Argentina and non-selective insecticides are still being used with...
Agriculture represents the second most important economic activity in the North Patagonian Region of Argentina and non-selective insecticides are still being used with significant implications to the quality of the environment. The range of concentrations (μg/L) determined for azinphosmethyl, chlorpyrifos, and carbaryl in drainage channels were from non-detected to 1.02, 1.45, and 11.21, respectively. Macroinvertebrate abundance and taxon richness in drainage channels were significantly lower in November compared to the other sampling months (October, February). The decrease in taxon richness observed in November was associated with chlorpyrifos and azinphosmethyl peak concentrations. The most remarkable changes were the decrease in sensitive taxa such as Baetidae and the increase in some tolerant taxa such as Chironomidae and Gastropoda.For all three pesticides, the acute hazard quotient exceeded the risk criteria for invertebrates. The effects of the three pesticides on aquatic organisms, characterized by joint probability curves, showed that the LC of 10% of the species were exceeded five and three times by the concentrations of azinphosmethyl and chlorpyrifos during the study period, respectively. However, the correlation between the pesticide concentrations and both taxon richness and abundance of macroinvertebrates at each site (irrigation and drainage channels) was indicative that only chlorpyrifos was negatively correlated with both parameters (Spearman r - 0.61, p = 0.0051 and Spearman r - 0.59, p = 0.0068 for taxon richness and abundance correlation, respectively). We conclude that macroinvertebrate assemblages in drainage channels were highly affected by chlorpyrifos levels.
Topics: Agriculture; Animals; Aquaporins; Argentina; Chlorpyrifos; Gastropoda; Insecticides; Pesticides; Water
PubMed: 29392605
DOI: 10.1007/s11356-018-1330-x -
Risk Analysis : An Official Publication... Jun 2018Implementation of probabilistic analyses in exposure assessment can provide valuable insight into the risks of those at the extremes of population distributions,... (Comparative Study)
Comparative Study
Implementation of probabilistic analyses in exposure assessment can provide valuable insight into the risks of those at the extremes of population distributions, including more vulnerable or sensitive subgroups. Incorporation of these analyses into current regulatory methods for occupational pesticide exposure is enabled by the exposure data sets and associated data currently used in the risk assessment approach of the Environmental Protection Agency (EPA). Monte Carlo simulations were performed on exposure measurements from the Agricultural Handler Exposure Database and the Pesticide Handler Exposure Database along with data from the Exposure Factors Handbook and other sources to calculate exposure rates for three different neurotoxic compounds (azinphos methyl, acetamiprid, emamectin benzoate) across four pesticide-handling scenarios. Probabilistic estimates of doses were compared with the no observable effect levels used in the EPA occupational risk assessments. Some percentage of workers were predicted to exceed the level of concern for all three compounds: 54% for azinphos methyl, 5% for acetamiprid, and 20% for emamectin benzoate. This finding has implications for pesticide risk assessment and offers an alternative procedure that may be more protective of those at the extremes of exposure than the current approach.
Topics: Agriculture; Air Pollutants; Algorithms; Azinphosmethyl; Databases, Factual; Humans; Inhalation Exposure; Ivermectin; Neonicotinoids; Occupational Exposure; Pesticides; Probability; Protective Clothing; Risk Assessment; Skin; United States; United States Environmental Protection Agency
PubMed: 29105804
DOI: 10.1111/risa.12936 -
The Science of the Total Environment Dec 2017Beeswax from Spain was collected during 2016 to determine pesticide residues incidence. The 35 samples were divided in foundation, old combs, cappings or virgin beeswax...
Beeswax from Spain was collected during 2016 to determine pesticide residues incidence. The 35 samples were divided in foundation, old combs, cappings or virgin beeswax to compare pesticide content between groups. Wax was screened for 58 pesticides or their degradation products by QuEChERS extraction and liquid chromatography mass spectrometry (LC-MS/MS). Beeswax was uniformly contaminated with acaricides and, to a much lesser extent, with insecticide and fungicide residues. Virgin followed by cappings were less contaminated than foundation and old combs beeswax. The miticides applied in-hive had a contribution to average pesticide load higher than 95%. Compounds widely used as acaricides, as coumaphos (100%), fluvalinate (86%) and amitraz (83%), were the pesticides most frequently detected with maximum concentrations of 26,858, 3593 and 6884ng·g, respectively. Chlorfenvinphos, acrinathrin and flumethrin, also acaricides, were detected in 77, 71 and 54%, respectively. Frequencies of pesticides used in crops were 40% for chlorpyrifos, 29% for dichlofenthion, 9% for malathion, 6% for fenthion-sulfoxide and 3% for azinphos-methyl, carbendazim, ethion, hexythiazox, imazalil and pyriproxyfen. Pesticide assessment in beeswax could be an excellent monitoring tool to establish veterinary treatments applied by beekeepers and environmental contaminants exposure of honey bees.
Topics: Animals; Bees; Pesticide Residues; Spain; Waxes
PubMed: 28679118
DOI: 10.1016/j.scitotenv.2017.06.174 -
Revista de Salud Publica (Bogota,... Aug 2016Objective Large quantities of pesticides are used in rice crops. The aim of this study is to characterize how farmers are exposed to pesticides and subsequent poisoning....
Objective Large quantities of pesticides are used in rice crops. The aim of this study is to characterize how farmers are exposed to pesticides and subsequent poisoning. Materials and Methods A multilevel (individual and community) multi-method study, which included ethnographic and survey methods, as well as measurement of pesticides in water and human samples, was performed. Results The production process is described and the main risk factors are presented. Pesticides are considered the greatest danger at work and at their homes. Workers have poor working conditions and are not protected by the system of occupational risks. Azinphos-methyl, endosulfan, β-BHC, bromophos-methyl, bromophos-ethyl and 2,4- DDT were found in water samples. The survey included 381 workers with mild (12.86 %), moderate (67.98 %) and severe (5.51 %) poisonings respectively. Severe cases presented lower levels of education, lower levels of health care access to the contributory regimen of the Colombian social security system and higher incidence of cardiovascular disease, diabetes, herpes or other viral infections. Conclusion There are precarious working conditions that favor exposure to pesticides correlated to the exclusion of farmers from the occupational risk system, to poverty and to poor education. It is urgent to include these workers to the system of occupational risk system and to improve their living conditions, thus reducing unsafe practices when handling pesticides.
Topics: Agricultural Workers' Diseases; Agriculture; Colombia; Crops, Agricultural; Farmers; Humans; Occupational Exposure; Oryza; Pesticides; Qualitative Research; Socioeconomic Factors; Water Pollutants, Chemical
PubMed: 28453066
DOI: 10.15446/rsap.v18n4.52617 -
Applied and Environmental Microbiology Jan 2017In a longitudinal agricultural community cohort sampling of 65 adult farmworkers and 52 adult nonfarmworkers, we investigated agricultural pesticide exposure-associated...
UNLABELLED
In a longitudinal agricultural community cohort sampling of 65 adult farmworkers and 52 adult nonfarmworkers, we investigated agricultural pesticide exposure-associated changes in the oral buccal microbiota. We found a seasonally persistent association between the detected blood concentration of the insecticide azinphos-methyl and the taxonomic composition of the buccal swab oral microbiome. Blood and buccal samples were collected concurrently from individual subjects in two seasons, spring/summer 2005 and winter 2006. Mass spectrometry quantified blood concentrations of the organophosphate insecticide azinphos-methyl. Buccal oral microbiome samples were 16S rRNA gene DNA sequenced, assigned to the bacterial taxonomy, and analyzed after "centered-log-ratio" transformation to handle the compositional nature of the proportional abundances of bacteria per sample. Nonparametric analysis of the transformed microbiome data for individuals with and without azinphos-methyl blood detection showed significant perturbations in seven common bacterial taxa (>0.5% of sample mean read depth), including significant reductions in members of the common oral bacterial genus Streptococcus Diversity in centered-log-ratio composition between individuals' microbiomes was also investigated using principal-component analysis (PCA) to reveal two primary PCA clusters of microbiome types. The spring/summer "exposed" microbiome cluster with significantly less bacterial diversity was enriched for farmworkers and contained 27 of the 30 individuals who also had azinphos-methyl agricultural pesticide exposure detected in the blood.
IMPORTANCE
In this study, we show in human subjects that organophosphate pesticide exposure is associated with large-scale significant alterations of the oral buccal microbiota composition, with extinctions of whole taxa suggested in some individuals. The persistence of this association from the spring/summer to the winter also suggests that long-lasting effects on the commensal microbiota have occurred. The important health-related outcomes of these agricultural community individuals' pesticide-associated microbiome perturbations are not understood at this time. Future investigations should index medical and dental records for common and chronic diseases that may be interactively caused by this association between pesticide exposure and microbiome alteration.
Topics: Adult; Azinphosmethyl; Bacteria; Farmers; Humans; Longitudinal Studies; Microbiota; Middle Aged; Mouth; Occupational Exposure; Pesticides; Washington; Young Adult
PubMed: 27836847
DOI: 10.1128/AEM.02149-16 -
Aquatic Toxicology (Amsterdam,... Nov 2016Organophosphate insecticides (OPs) continue to be an important class of agrochemicals used in modern agriculture worldwide. Even though these pesticides persist in the...
In vitro and in vivo studies of cholinesterases and carboxylesterases in Planorbarius corneus exposed to a phosphorodithioate insecticide: Finding the most sensitive combination of enzymes, substrates, tissues and recovery capacity.
Organophosphate insecticides (OPs) continue to be an important class of agrochemicals used in modern agriculture worldwide. Even though these pesticides persist in the environment for a relatively short time, they show a high acute toxicity that may represent a serious hazard for wildlife. Sub-lethal effects on non-target species are a focus in pest management programs and should be used as biomarkers. Cholinesterases (ChEs) are the most used biomarker of OP exposure in vertebrate and invertebrate species. However, the combined monitoring of ChE and carboxylesterase (CE) activities may provide a more useful indication of exposure and effect of the organisms. The objective of the present work was to find the most sensitive combination of enzyme, substrate, tissue and capacity to recovery of B-esterases in the freshwater gastropod Planorbarius corneus exposed to the OP azinphos-methyl. For this purpose, ChE and CE activities in different tissues of P. corneus (head-foot, pulmonary region, digestive gland, gonads and whole organism soft tissue) were studied. Measurements of ChE activity were performed using three substrates: acetylthiocholine, propionylthiocholine and butyrylthiocholine and CE activity using four different substrates: p-nitrophenyl acetate, p-nitrophenyl butyrate, 1-naphthyl acetate, and 2-naphthyl acetate in control and exposed organisms. Finally, the recovery rates of ChE and CE activities following 48h exposure to azinphos-methyl were analyzed. Our results show a preference for acetylthiocholine as substrate, a high inhibition with eserine (a selective ChE inhibitor) and inhibition with excess of substrate in all the analyzed tissues. The highest ChE and CE activity was found in the pulmonary region and in the digestive gland, respectively. The highest CE V was obtained with 1 and 2-naphthyl acetate in all the tissues. CEs were more sensitive than ChE to azinphos-methyl exposure. The highest sensitivity was found using p-nitrophenyl acetate and butyrate as substrates. On the other hand, CEs of the digestive gland and the pulmonary region were more sensitive than CEs of the whole organism soft tissue. Regarding the recovery of enzyme activities after 48h exposure, ChE and CEs with p-nitrophenyl butyrate reached control values after 14days in the digestive gland and after 21days in the pulmonary region. Our results show marked differences in P. corneus basal ChE and CE activities depending on substrates and the tissue. Also, both tissue-dependent and substrate-dependent variations in sensitivity to azinphos-methyl exposure and recovery were obtained. CEs measured with p-nitrophenyl butyrate in the pulmonary region were the best combination to be used as biomarker of exposure to azinphos-methyl due to their sensitivity and low recovery capacity. Environmental concentrations of azinphos-methyl inhibited CE activity so they could be used as effective biomarkers of aquatic contamination.
Topics: Animals; Azinphosmethyl; Biomarkers; Butyrates; Carboxylic Ester Hydrolases; Cholinesterases; Inhibitory Concentration 50; Insecticides; Kinetics; Nitrophenols; Organophosphorus Compounds; Snails; Substrate Specificity; Water Pollutants, Chemical
PubMed: 27723570
DOI: 10.1016/j.aquatox.2016.10.002