Fifteen Years of Experience in Cholinesterase Monitoring of Insecticide Applicators

Lessenger, James E.

doi:10.1300/j096v10n03_06

Cited by 19 publications

(16 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The blood cholinesterase activity was also determined to monitor the exposure to organophosphorus and carbamates pesticides [15][16][17][18][19][20]. The activity of cholinesterase was determined in the samples of sera using as substrate the butyrylthiocholine, which is hydrolyzed by the enzyme into butyrate and thiocholine.…”

Section: Methodsmentioning

confidence: 99%

Multiple pesticides exposure of greenhouse workers and thyroid parameters

Simescu¹,

Igna²,

Nicolaescu³

et al. 2014

Int. J. SDP

View full text Add to dashboard Cite

Objective: The persistence of high prevalence of thyroid pathology (goiter, nodules) in Romanian population, despite the correction of iodine defi ciency, determined us to evaluate the impact of factors different than iodine intake on the thyroid gland as environmental endocrine disruptors. We studied the potential correlation between pesticide exposure and parameters of the function, autoimmunity and morphology of the thyroid in a group of greenhouse workers (GHWs) exposed to multiple uncontrolled pesticides across agricultural seasons. Materials and methods: A group of 108 GHWs, 18-78 year olds, with normal iodine intake, from a plain village, exposed to multiple pesticides was enrolled voluntary in this study. Thyroid echography, thyroid parameters [thyroid stimulating hormone (TSH), free T4 (FT4), and antibody to thyroid peroxidase (ATPO)], some of the used pesticides (chlorpyrifos, trichloropyridinol (TCP), carbofurane, cypermethrin, dimethoate) and cholinesterase activity were determined in biological samples (urine, blood) collected across two agricultural seasons. Results: The median urinary iodine concentration in children from this village was 135.20 µg/L, while median TSH and median FT4 was 1.72 μUI/mL and 16.68 pmol/L, respectively. Hypothyroidism (TSH > 4.2 μUI/mL) was present in 12.4% of patients, median TSH value was 7.26 μUI/mL. In four of them post-thyroidectomy hypothyroidism was present. Elevated titres of anti-TPO antibodies were found in 22 (20.37%). Echographic pattern of thyroiditis was present in 16.49% of the patients, and thyroid nodules were detected by ultrasonography in 38.13%. There were two subjects with Graves' disease. The detectable level of TCP was bigger in the fi rst season (range 120-190 μg/L) than in the second (range 0.7-1.7 μg/L). The range of seasonal concentration of urinary carbofurane was 0.004-0.25 μg/mL. Cypermethrin was detected in a small number of subjects (range: 12.5-13.3 μg/g creatinine). Dimethoate was undetectable. Conclusions: The distribution of thyroid disorders in study group living in an area with normal iodine intake did not differ from known epidemiological studies. The most frequently encountered pesticide was chlorpyrifos. Some samples presented several pesticides simultaneously.

show abstract

Section: Methodsmentioning

confidence: 99%

Multiple pesticides exposure of greenhouse workers and thyroid parameters

Simescu¹,

Igna²,

Nicolaescu³

et al. 2014

Int. J. SDP

View full text Add to dashboard Cite

show abstract

“…Because of the essentially irreversible binding of organophosphorus pesticides to red blood cell cholinesterase, recovery from cholinesterase depression is prolonged, reflecting the 120-day half-life of red blood cells. This, plus the wide range of normal values for cholinesterase, makes repeated measures the best means of detecting cholinesterase depression (Flegar-Meštrić et al 1999; Lessenger 2005; Lessenger and Reese 1999; Mutch et al 1992). Routine screening for cholinesterase depression is mandated in only a few places [e.g., California and Washington State (Hofmann et al 2008; Lessenger 2005)] and then only for workers applying and handling pesticides and not those carrying out routine fieldwork.…”

mentioning

confidence: 99%

Cholinesterase Depression and Its Association with Pesticide Exposure across the Agricultural Season among Latino Farmworkers in North Carolina

Quandt¹,

Chen

Grzywacz

et al. 2010

Environ Health Perspect

View full text Add to dashboard Cite

BackgroundFarmworkers can be exposed to a wide variety of pesticides. Assessing cholinesterase activity over time can be used to monitor exposure to organophosphorus and carbamate pesticides.ObjectivesThe goal of this study was to document patterns and variation in cholinesterase levels across the agricultural season (May–August) among field-workers, and to explore the association of cholinesterase depression with pesticide exposure across the agricultural season.MethodsDried blood samples collected from 231 migrant farmworkers sampled from camps in eastern North Carolina up to four times across a summer agricultural season were analyzed for cholinesterase activity, and urine samples were analyzed for metabolites of organophosphorus and carbamate pesticides. Reductions of ≥ 15% from an individual’s highest value were identified and considered evidence of meaningful cholinesterase activity depression.ResultsThe average cholinesterase activity levels were lowest in June, with significantly higher mean values in July and August. When adjusted for age, sex, minutes waited to shower, and days worked in the fields, the number of organophosphorus and carbamate pesticides detected in urine predicted reductions in cholinesterase activity.ConclusionsThese data demonstrate that workers are experiencing pesticide exposure. Greater enforcement of existing safety regulations or strengthening of these regulations may be warranted. This study demonstrates that serial measurements of cholinesterase activity across an agricultural season can detect exposure to pesticides among field-workers.

show abstract

“…An assessment of the RBC AChE monitoring program in California over the 1989-2004 period found that after workers (insecticide applicators) were removed from organophosphate exposures based on RBC AChE that is 70% of baseline, recovery period averaged 5.4 weeks, had a standard deviation of 4.0 weeks, and ranged from 0.3 to 13 weeks (135).…”

Section: Red Blood Cell Acetylcholinesterasementioning

confidence: 99%

Organophosphorus Pesticides

Storm¹

2012

Patty's Toxicology

View full text Add to dashboard Cite

Most organophosphorus compounds today fall into two general groups: the so‐called nerve agents, that are very acutely toxic and organophosphorus pesticides that are less toxic. Nerve agents were generally the first toxic organophosphorus developed, and were the original basis for organophosphorus pesticides. Interest about nerve agents has increased lately given concerns about their potential use in terrorist acts. Organophosphate nerve agents and pesticides are a highly diverse group of chemicals. They are all characterized by their ability to inhibit the enzyme acetylcholinesterase (AChE) that deactivates the neurotransmitter acetylcholine (ACh). At present, the widest use of organophosphorus compounds is as pesticides, although they have also been used as therapeutic agents, gasoline additives, hydraulic fluids, cotton defoliants, fire retardants, plastic components, growth regulators, and industrial intermediates to a much smaller extent. Compounds in this class are numerous and have been categorized in many ways according to the nature of the substituents. Gallo and Lawryk (1991) [2], for example, categorized them into four main groups I–IV based on the characteristics of the leaving group (X). Group I compounds, phosphorylcholines, have a leaving group that contains a quaternary nitrogen and are among the most potent organophosphates (e.g., Shradan). Group II compounds, fluorophosphates, have a fluoride leaving group and are also generally highly toxic (e.g., diisopropyl fluorophosphate). Group III compounds have leaving groups that contain cyanide or a halogen other than fluoride and are generally less potent than group I or II (e.g., Parathion). Group IV contains most of the organophosphates used as insecticides today. These compounds have alkoxy, alkylthio, aryloxy, arylthio, or heterocyclic leaving groups and a wide variety of other substituents. Another classification scheme is based on the nature of the atoms that immediately surround the central phosphorus atom and results in 14 different categories. According to this scheme, phosphates are the prototype for the entire class and are those compounds where all four atoms that surround the phosphorus atom are oxygen (e.g., dichlorvos, mevinphos). Sulfur‐containing organophosphate compounds (phosphorothioates, phosphorothiolates, phosphorodithioates, and phosphorodithiolates) are far more numerous than phosphates and include well‐recognized organophosphate insecticides such as parathion, diazinon, chlorpyrifos, etc. Other groups contain nitrogen (phosphoramides and phosphorodiamides), nitrogen and sulfur (phosphoramidothionates and phosphoramidothiolates), carbon (phosphonates and phosphinates), or carbon and sulfur (phosphonothionates, phosphonothionothiolates, and phosphinothionates). All aspects of organophosphate chemistry, toxicity, analysis, and exposure potential have been previously and comprehensively reviewed. In addition, information regarding the toxicity of organophosphorus pesticides in particular has expanded greatly in recent years as a result of toxicity data supplied by registrants to the U.S. EPA's Office of Pesticides to support reregistration. These data have been made publicly available by the U.S. EPA on its Internet Web site ( www.epa.gov/pesticides ). The following discussion draws heavily from recent reviews and also includes summaries of relevant toxicity data submitted to, and made available by, the U.S. EPA.

show abstract

Fifteen Years of Experience in Cholinesterase Monitoring of Insecticide Applicators

Abstract: The California ChE monitoring program serves as a useful and cost-effective means of preventing organophosphate and carbamate overexposure. Elimination of the third baseline test requirement should be considered.

Cited by 19 publications

References 9 publications

Multiple pesticides exposure of greenhouse workers and thyroid parameters

Multiple pesticides exposure of greenhouse workers and thyroid parameters

Cholinesterase Depression and Its Association with Pesticide Exposure across the Agricultural Season among Latino Farmworkers in North Carolina

Organophosphorus Pesticides

Contact Info

Product

Resources

About