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Exposure of pet dogs and cats to pesticides used in and around homes (e.g., lawns and gardens) is a significant health concern. Furthermore, some pesticides are directly used on dogs and cats for flea, lice, and tick control. Despite this, little is known regarding the extent of pesticide exposure in pets. In this study, we determined the concentrations of 30 biomarkers of pesticide exposure in urine collected from dogs and cats in New York State, USA: 6 dialkylphosphate (DAP) metabolites of organophosphates (OPs); 14 neonicotinoids (neonics); 3 specific metabolites of OPs; 5 pyrethroids (PYRs); and 2 phenoxy acids (PAs). The sum median concentrations of these 30 pesticide biomarkers (ΣPesticides) in dog and cat urine were 35.2 and 38.1 ng/mL, respectively. Neonics were the most prevalent in dogs (accounting for 43% of the total concentrations), followed by DAPs (17%), PYRs (16%), OPs (13%), and PAs (∼10%). In cat urine, neonics alone accounted for 83% of the total concentrations. Elevated concentrations of imidacloprid were found in the urine of certain dogs (max: 115 ng/mL) and cats (max: 1090 ng/mL). Some pesticides showed gender- and sampling location- related differences in urinary concentrations. We calculated daily exposure doses of pesticides from the measured urinary concentrations through a reverse dosimetry approach. The estimated daily intakes (DIs) of chlorpyrifos, diazinon, and cypermethrin were above the chronic reference doses (cRfDs) in 22, 76, and 5%, respectively, of dogs. The DIs of chlorpyrifos, parathion, diazinon, and imidacloprid were above the cRfDs in 33, 14, 100, and 29%, respectively, of cats. This study thus provides evidence that pet dogs and cats are exposed to certain pesticides at levels that warrant immediate attention., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Microconstituents are beginning to make their way into discharge permits in the United States. Removal of microconstituents often requires tertiary treatment, and utilities are interested to know what permit limits they might expect in the future as they plan for capital improvements. The U.S. Environmental Protection Agency (EPA) is currently focusing on developing methods for determining the endocrine-disrupting impact of particular compounds. EPA has developed some criteria for endocrine-disrupting compounds (EDCs), but the states have been slow to turn these criteria into standards, and their inclusion into permits is much slower. While several states are moving forward with developing standards for diazinon, PCBs, nonylphenol, atrazine, and tributyltin, permit holders probably will not see EDCs in permits in the near future. [ABSTRACT FROM AUTHOR]

Johnson, Henry M., Joseph L. Domagalski, and Dina K. Saleh, 2010. Trends in Pesticide Concentrations in Streams of the Western United States, 1993-2005. Journal of the American Water Resources Association (JAWRA) 00(0):1-22. DOI: 10.1111/j.1752-1688.2010.00507.x Trends in pesticide concentrations for 15 streams in California, Oregon, Washington, and Idaho were determined for the organophosphate insecticides chlorpyrifos and diazinon and the herbicides atrazine, s-ethyl diproplythiocarbamate (EPTC), metolachlor, simazine, and trifluralin. A parametric regression model was used to account for flow, seasonality, and antecedent hydrologic conditions and thereby estimate trends in pesticide concentrations in streams arising from changes in use amount and application method in their associated catchments. Decreasing trends most often were observed for diazinon, and reflect the shift to alternative pesticides by farmers, commercial applicators, and homeowners because of use restrictions and product cancelation. Consistent trends were observed for several herbicides, including upward trends in simazine at urban-influenced sites from 2000 to 2005, and downward trends in atrazine and EPTC at agricultural sites from the mid-1990s to 2005. The model provided additional information about pesticide occurrence and transport in the modeled streams. Two examples are presented and briefly discussed: (1) timing of peak concentrations for individual compounds varied greatly across this geographic gradient because of different application periods and the effects of local rain patterns, irrigation, and soil drainage and (2) reconstructions of continuous diazinon concentrations at sites in California are used to evaluate compliance with total maximum daily load targets. [ABSTRACT FROM AUTHOR]

ABSTRACT Diazinon has been used extensively in the past as part of California eradication programs for tephritid fruit flies (Diptera: Tephritidae) as a soil drench, but it is being phased Out for this purpose in the United States. Therefore, in this study, the toxicity of Platinum, Force, Admire, Regent, and Warrior was estimated after application to sand and soil as drenches for control of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann); melon fly, Bactrocera cucurbitae (Coquillett); and oriental fruit fly, Bactrocera dorsali.s (Hendel), in Hawaii. Susceptibility of each species differed. In sand, the order of toxicity at LC[sub50] based on the 95% confidence limit overlap approach for C. capitata from most toxic to least toxic was diazinon > Force = Warrior > Admire = Platinum > Regent. The order of toxicity for B. dorsali.s was diazinon > Platinum = Warrior = Force > Regent = Admire. The order of toxicity for B. cucurbitae was Warrior = diazinon > Force = Regent = Platinum = Admire. Based on the dose ratio method, Warrior was not significantly different at LC[sub50] than diazinon for B. cucurbitae only. All other insecticides were significantly different from diazinon at LC[sub50]. Studies in sand were followed by an evaluation of specific concentrations of Warrior and Force in soil collected from two sites on the island of Kauai. Average concentrations that caused at least 95% mortality in soil in all three fruit fly species were 121 g active ingredient (Al) /ha for Force and 363 g (Al) /ha for Warrior compared with 182 g (Al) /ha for diazinon. These results indicate that Force and Warrior could be used as soil treatments for control of tephritid fruit flies. [ABSTRACT FROM AUTHOR]

Sub-cooled liquid vapor pressures (PL0) of current-use organochlorine and organophosphate pesticides (chlorothalonil, chlorpyrifos methyl, diazinon, fipronil) and selected transformation products (chlorpyrifos oxon, heptachlor epoxide, oxychlordane, 3,5,6-trichloro-2-pyridinol) were determined at multiple temperatures using the gas chromatography retention time technique. Results were utilized to determine vapor pressure-temperature relationships and to calculate enthalpies of vaporization (ΔHvap). While results for chlorothalonil and diazinon were comparable with published values, the measured value for fipronil (1.82 × 10- 6 Pa) is almost an order of magnitude higher than the reported literature value (3.7 × 10- 7 Pa). The availability of vapor pressure temperature relationships for these chemicals will aid in pesticide risk assessment development and improve the effectiveness of mitigation and remediation efforts. [ABSTRACT FROM AUTHOR]

BACKGROUND: Residential insecticide use is widespread in the United States, but few data are available on the persistence and variability in levels in the indoor environment. OBJECTIVE: The study aim was to assess within-and between-home variability in indoor-air insecticides over the final 2 months of pregnancy among a cohort of African-American and Dominican women from New York City. METHODS: Women not employed outside the home were enrolled between February 2001 and May 2004 (n = 102); 9 insecticides and an adjuvant were measured in 48-hr personal air samples and 2-week integrated indoor air samples collected sequentially for 7.0 ± 2.3 weeks (n = 337 air samples). RESULTS: Sixty-one percent of the women reported using pest control during the air samplings. Chlorpyrifos, diazinon, and propoxur were detected in 99-100% of personal and indoor samples (range, 0.4-641 ng/m³). Piperonyl butoxide (a pyrethroid adjuvant) was detected in 45.5-68. 5% (0. 2-608 ng/m³). There was little within-home variability and no significant difference in air concentrations within homes over time (p = 0.2); between-home variability accounted for 88% of the variance in the indoor air levels of propoxur, 92% in chlorpyrifos, 94% in diazinon, and 62% in piperonyl butoxide (p < 0.001). Indoor and maternal personal air insecticide levels were highly correlated (r = 0.7-0.9, p < 0.001). Diazinon and chlorpyrifos levels declined 5-fold between 2001 and 2004 but were detected in all homes 1.5 and 2.5 years, respectively, after the U.S. Environmental Protection Agency ban on their residential use. CONCLUSION: Results showed that the insecticides were persistent in the home with little variability in air concentrations over the 2 months and contributed to chronic maternal inhalation exposures during pregnancy. [ABSTRACT FROM AUTHOR]

We conducted two laboratory subacute dietary toxicity tests and one outdoor subacute dietary toxicity test to determine the effectiveness of the U.S. Environmental Protection Agency's deterministic risk assessment model for evaluating the potential of adverse effects to birds in the field. We tested technical-grade diazinon and its D·Z·N® 50W (50% diazinon active ingredient wettable powder) formulation on Canada goose (Branta canadensis) goslings. Brain acetylcholinesterase activity was measured, and the feathers and skin, feet, and gastrointestinal contents were analyzed for diazinon residues. The dose-response curves showed that diazinon was significantly more toxic to goslings in the outdoor test than in the laboratory tests. The deterministic risk assessment method identified the potential for risk to birds in general, but the factors associated with extrapolating from the laboratory to the field, and from the laboratory test species to other species, resulted in the underestimation of risk to the goslings. The present study indicates that laboratory-based risk quotients should be interpreted with caution. [ABSTRACT FROM AUTHOR]

Abstract: Samples collected from rural and urban streams in the City of Denton, Texas, USA were analyzed for the organophosphorus pesticide diazinon during the years preceding and following a United States Environmental Protection Agency ban on many diazinon uses. A network of 70 monitoring stations, based mainly on topography and hydrological considerations, were established within the three main watersheds of Denton. Monitoring stations were sampled monthly from March through August during periods of normal flow (baseflow), resulting in a total of 1243 samples collected during the years of 2001–2004. Pesticide concentrations were determined using commercially available enzyme-linked immunosorbent assays (ELISAs) specific for diazinon. Results from this temporally and spatially dense monitoring effort illustrated the impacts of a decrease in diazinon production during 2002, followed by a ban on most outdoor, non-agricultural diazinon retail sales imposed during 2003. The total number of samples exhibiting diazinon concentrations above the lower limits of detection (LLD) significantly decreased between 2001 through 2004 (Mantel–Haenszel Chi-Square test, p<0.0001, n=1243) and decreased significantly during the four monitoring years (Cochran–Armitage Trend test, z=−17.94, p<0.0001, n=1243). The total number of stations exhibiting at least one sample above the LLD during the four monitoring years showed similar patterns (Mantel–Haenszel Chi-Square test, p<0.0001; Cochran–Armitage Trend test, z=−3.21, p=0.0007; n=276). Results indicate that the phased reduction of outdoor, non-agricultural diazinon uses led to a highly significant decrease in surface water occurrences of this pesticide. [Copyright &y& Elsevier]

Environmental exposures generally involve chemical mixtures instead of single chemicals. Statistical models such as the fixed-ratio ray design, wherein the mixing ratio (proportions) of the chemicals is fixed across increasing mixture doses, allows for the detection and characterization of interactions among the chemicals. In this study, we tested for interaction(s) in a mixture of five organophosphorus (OP) pesticides (chlorpyrifos, diazinon, dimethoate, acephate, and malathion). The ratio of the five pesticides (full ray) reflected the relative dietary exposure estimates of the general population as projected by the US EPA Dietary Exposure Evaluation Model (DEEM). A second mixture was tested using the same dose levels of all pesticides, but excluding malathion (reduced ray). The experimental approach first required characterization of dose-response curves for the individual OPs to build a dose-additivity model. A series of behavioral measures were evaluated in adult male Long-Evans rats at the time of peak effect following a single oral dose, and then tissues were collected for measurement of cholinesterase (ChE) activity. Neurochemical (blood and brain cholinesterase [ChE] activity) and behavioral (motor activity, gait score, tail-pinch response score) endpoints were evaluated statistically for evidence of additivity. The additivity model constructed from the single chemical data was used to predict the effects of the pesticide mixture along the full ray (10–450 mg/kg) and the reduced ray (1.75–78.8 mg/kg). The experimental mixture data were also modeled and statistically compared to the additivity models. Analysis of the 5-OP mixture (the full ray) revealed significant deviation from additivity for all endpoints except tail-pinch response. Greater-than-additive responses (synergism) were observed at the lower doses of the 5-OP mixture, which contained non-effective dose levels of each of the components. The predicted effective doses (ED20, ED50) were about half that predicted by additivity, and for brain ChE and motor activity, there was a threshold shift in the dose-response curves. For the brain ChE and motor activity, there was no difference between the full (5-OP mixture) and reduced (4-OP mixture) rays, indicating that malathion did not influence the non-additivity. While the reduced ray for blood ChE showed greater deviation from additivity without malathion in the mixture, the non-additivity observed for the gait score was reversed when malathion was removed. Thus, greater-than-additive interactions were detected for both the full and reduced ray mixtures, and the role of malathion in the interactions varied depending on the endpoint. In all cases, the deviations from additivity occurred at the lower end of the dose-response curves. [ABSTRACT FROM AUTHOR]

Monitoring studies show that urban surface streams in the United States are commonly contaminated with pesticides, and contamination by organophosphates and carbamates is of particular concern because of their aquatic toxicity. The degradation and sorption of four common organophosphate and carbamate insecticides were studied in urban creek sediments from southern California, USA. In sediment, malathion was quickly degraded under either aerobic or anaerobic conditions, with a half-life (t½) lt;3 d. Diazinon and chlorpyrifos were moderately persistent under aerobic conditions (t½ = 14-24 d). However, persistence of chlorpyrifos increased significantly under anaerobic conditions, and t½ was prolonged to 58 to 223 d. The greatest effect of redox potential was found with carbaryl. Although rapid dissipation occurred under aerobic conditions (t½ = 1.8-4.9 d), carbaryl became virtually nondegradable under anaerobic conditions (t½ = 125-746 d). The sorption coefficient consistently increased with time for all pesticides, and chlorpyrifos displayed greater sorption potential than the other pesticides. This study indicates that pesticides in sediment may become less available with time because of increased sorption, and pesticide persistence in sediment may vary greatly among compounds and with redox conditions. Under anaerobic conditions, long persistence may occur even for nonpersistent compounds. [ABSTRACT FROM AUTHOR]

Post-application temporal and spatial distributions of two organophosphorus pesticides, diazinon (O,O-diethyl O-[6-methyl-2-(1-methylethyl)-4-pyrimidinyl] phosphorothioate, CAS No. 333-41-5) and chlorpyrifos [O,O-diethyl-O-(2-isopropyl-6-methyl-4-pyrimidinyl) phosphorothioate, CAS No. 2921-88-2], were monitored after homeowner applications for indoor and outdoor insect control. Samples of indoor air, vacuumable carpet dust, carpet dislodgeable residues, deposits on bare floors, table tops and dinnerware, surrogate food, and residues on children's hands and toys were taken before and up to 12 days after treatments in the family room, kitchen, and child's bedroom. Results from the study demonstrate the nature and magnitude of translocation of pesticides from the areas of application to surfaces accessible for human contact and permit comparisons of potential exposures via respiration and dermal contact/oral ingestion. Potential indoor inhalation exposures were estimated to be as high as 0.5 µg/kg/day for diazinon applied indoors and 0.05 µg/kg/day for chlorpyrifos applied to the outside perimeter of the house. While ingestion of carpet dust at the rate of 100 µg/day would have added a maximum of only ∼0.01 µg/kg/day to the daily dose, residues found on the children's hands suggest that repeated mouthing could have contributed as much as 1-1.5 µg/kg/day. These estimates are below the U.S. Environmental Protection Agency (EPA) reference dose for chlorpyrifos, but exceed those for diazinon. [ABSTRACT FROM AUTHOR]

Little is known of the occurrence of pesticides in urban streams compared to streams draining agricultural areas. Water samples from eight urban streams from across the United States were analyzed for 75 pesticides and seven transformation products. For six of the eight urban streams, paired agricultural streams were used for comparisons. The herbicides detected most frequently in the urban streams were prometon, simazine, atrazine, tebuthiuron, and metolachlor, and the insecticides detected most frequently were diazinon, carbaryl, chlorpyrifos, and malathion. In contrast to similar-sized agricultural streams, total insecticide concentrations commonly exceeded total herbicide concentrations in these urban streams. In general, the temporal concentration patterns in the urban streams were consistent with the characteristics of the local growing season. The insecticides carbaryl and diazinon exceeded criteria for the protection of aquatic life in many of the urban streams in the spring and summer. When the country as a whole is considered, the estimated mass of herbicides contributed by urban areas to streams is dwarfed by the estimated contribution from agricultural areas, but for insecticides, contributions from urban and agricultural areas may be similar. The results of this study suggest that urban areas should not be overlooked when assessing sources and monitoring the occurrence of pesticides in surface waters. [ABSTRACT FROM AUTHOR]

This article presents information related to susceptibility of five nontarget organisms to Diazinon Exposure. Diazinon is an organophosphorus insecticide widely used on various agricultural crops and is an active ingredient in many commercial fireant repellents. In 1990 and 1992, approximately 36,000 kg were applied to the Imperial Valley in California. Also, in 1990, approximately 295,000 kg of diazinon was applied to Central Valley, CA.. Almost 4 million kilograms are produced and used for professional pest control, by private users in homes and gardens, in agriculture and on turf in the United States alone.

The article examines laboratory and field enzyme-immunoassay (EIA) for diazinon and their application to residue analysis in lanolin, water and fruit juice by researchers from Australia and the U.S. In this study, the researchers describe the development of laboratory and field competitive IEA formats, based on polyclonal antibodies. These provide an alternate method of diazinon quantitation, and require little or no cleanup or sample concentration for detection of residues in well water, lanolin and fruit juice.

The article presents a study on the insecticide residues in the ambient air of commercial pest control buildings in the U.S. It was reported that there are presence of certain organophosphates in the ambient air of commercial pest control. Insecticides in the storage rooms of 10 North Carolina commercial pest control firms were inventoried during February 1993. Five insecticide storage rooms were in buildings with the offices and 5 were in buildings separate from the offices. Air samples were taken to the laboratory and analyzed for acephate, bendiocarb, chlorpyrifos, cypermethrin, and diazinon.

Background. Swiss cheese (sws) is a Drosophila melanogaster ortholog of human Neuropathy target esterase (NTE or PLPLA6), a molecular target for the organophosphorus compound-induced delayed neuropathy (OPIDN). SWS is a transmembrane protein, loss of its function causes age-dependent neurodegeneration, glial hyperwrapping, and neuronal apoptosis. As shown previously, the sws mutants have decreased lifespan. This phenotype is accelerated even further when animals are starved or fed with organophosphates. Our aim was to find genes-partners of sws in order to clarify in which cell the signaling SWS is involved and to understand better the cellular mechanism of SWS/NTE-dependent neuropathy formation. Methods. Based on in-silico predictions and theoretical searching we selected 25 candidate genes that can potentially interact with SWS. To verify their functional interactions with SWS in vivo, we analyzed heterozygous animals with a reduction by one copy of the candidate gene in the sws mutant background (sws1). We analyzed three sws–related phenotypes: sensitivity to starvation, viability after organophosphate Diazinon treatment and brain tissue degeneration. To verify the sensitivity to starvation, 4–6 day-old flies were collected and transferred to vials with [the] control solution (10 % sucrose, 1 % yeast extract) or only with water; during next 6 days we counted dead flies. After 24-hour exposition to 0.0015 mg/ml Diazinon[, the] flies were transferred to a standard food vial, and their survival during next 14 days was estimated using GraphPad Prism 6 (Graphpad Software Inc., La Jolla, CA, USA). Log-rank test was used to estimate statistically significant difference. For brain tissue analysis we made paraffin sections of head from 20 day-old flies. Histological preparations were analyzed in UV light using a microscope Loboval-3 (Zeiss-Jena, Germany). Results. We tested if downregulation of a potential interactor would rescue or further accelerate the reduced lifespan phenotype under stress conditions. Currently, we have tested 11 out of 25 candidate genes. Our analysis showed that several genes: Dl (Delta), rl (rolled), ena (enabled), nes (nessy), Lar (Leukocyteantigen-related-like) and park show genetic interactions with sws. Interestingly, heterozygous flies for Dl, rl, nes, Lar and ena were resistant to both stress factors – Diazinon treatment and nutrition deprivation (starvation) and could partially rescue sws phenotype. Reduction of Dl, ena and rl in the sws mutants could also rescue severe brain neurodegeneration observed in [the] sws mutants. Conclusions. We found at least three genes-modulator of sws-phenotype, suggesting that reduced expression of these genes could play a neuroprotective role in toxicity- and stress induced neuropathies. At this time, the screening is going on. [ABSTRACT FROM AUTHOR]

Discusses the report released by the U.S. Geological Survey which indicates that the toxic pesticides diazinon and chlorpyrifos were found in all rainfall samples collected in Modesto, California. Pesticides concentrations; Exceeding of the state guidelines for diazinon concentrations.

Presents environmental health news worldwide for the month of June 2001. Reduction of the harmful emissions produced by school buses in California; Development of a lead-detecting sensor at the University of Illinois; Lead screening for children in China; Ban on the indoor use of the pesticide diazinon in the United States; Reduction of mercury emissions from power plants.

The article reports on the use of pesticides during pregnancy. It discusses a study of pesticide use before and after the U.S. Environmental Protection Agency (EPA) restricted the sale of chlorpyrifos and diazinon. It was found that replacement pesticides are filling the void created by the restriction. Air samples gathered five years after the restriction showed high levels of chlorpyrifos and diazinon. Despite the risks toward pregnancy, pesticide use continues in order to combat household pests.

The article reports on the increasing use of pesticides in the U.S. as of June 2005. The Environmental Protection Agency phased out two common household insecticides, diazinon and chlorpyrifos due to its effect on health and environmental risk. The report "Toxic Tradeoff: Exit Diazinon Enter Carbaryl," found that people switched to the hazardous insecticide carbaryl. It was found that the sales for carbaryl increased tenfold over a one year period. Washington Toxics Coalition staff Philip Dickey looked if there was also an increase in water contamination. It was suggested that consumers should turn to pesticide-free solutions for pest control.