How can simple household procedures reduce exposure to pesticides from fruits and vegetables: current habits and recommendations

Prenatal exposure to pyrethroid and organophosphate insecticides and language development at age 20-36 months among children in the Odense Child Cohort.

Reference values for metabolites of pyrethroid and organophosphorous insecticides in urine for human biomonitoring in environmental medicine

Background: Exposure to organophosphate insecticides has been associated with neurobehavioral deficits in children, although data on low levels of exposure experienced by the general population is sparse. Pyrethroids are another class of insecticides rapidly gaining popularity, and epidemiological evidence on their potential effects are lacking. Aims: Our goal was to examine the association of organophosphate and pyrethroid insecticides exposure with behavioral problems in Canadian children aged 6 to 11 years. Methods: We used data on 1081 children ages 6 to 11 years from the Canadian Health Measures Survey (2007-2009). We performed logistic regression to examine odds of behavioral problems, indicated by high scores on the Strengths and Difficulties Questionnaire, in relation with pyrethroid and organophosphate insecticides metabolites in urine, adjusting for covariates, and accounting for the sampling design. Results: Urinary concentrations of organophosphate metabolites were not significantly associated with behavioral problems. Higher concentration of the pyrethroid metabolite cis-DCCA was associated with behavioral problems (p=0.03), and there was a trend for trans-DCCA (p=0.12). For a 10-fold increase in cis-DCCA and trans-DCCA concentrations, the odds ratios (ORs) were 2.0 (CI95%, 1.1 to 3.6) and 1.6 (CI95%, 0.9 to 3.0), respectively. Another metabolite common to many pyrethroids, 3-PBA, was associated with conduct disorders among girls (OR, 2.2 [CI95% 1.0, 4.9]) but not boys (OR, 0.6 [CI95%, 0.3, 1.4]), although this association did not remain significant after accounting for the complex design (p=0.10). Conclusion: We did not observe the previously reported association between organophosphate insecticides and behavioral problems in children. However, our findings suggest that pyrethroids were associated with these problems. This is the first study to suggest this, and further research is needed on potential risks of exposure to pyrethroid insecticides for children’s development.

Improving Behavior of Lead-Exposed Children: Micronutrient Supplementation, Chelation, or Prevention

Neonicotinoids in U.S. maize: Insecticide substitution effects and environmental risk

This study exploits a novel dataset containing more than 89,000 farm-level surveys over a 17-year period to investigate how neonicotinoid seed treatments in maize, now ubiquitous, have affected the use of other insecticides. Neonicotinoid insecticides are the most used class of insecticides in the world, but they are controversial because of their high toxicity to honeybees. In the United States, maize production accounts for the majority of neonicotinoid use, mostly as seed treatments. We find that neonicotinoids substituted for other major insecticides: plots planted with neonicotinoid-treated seeds were 52% and 47% less likely to be treated with a pyrethroid and organophosphate insecticide, respectively. Although honeybees have been put at greater risk by neonicotinoids, the changed pattern of pest control instruments has reduced toxicity risk for mammals, birds, and fish. We also find that adoption of genetically engineered insect-resistant maize varieties significantly reduced the use of organophosphate and pyrethroid insecticides, thereby reducing toxicity exposure to all examined taxa. Policies aimed at restricting neonicotinoid use may need to account for undesirable unintended consequences.

Non specific esterase are known to be important detoxification enzyme contributing to development of insecticides resistance in mosquitoes. Elevated esterase activity is one of the mechanisms of resistance to organophosphate, carbamate and pyrethroid insecticides in the mosquitoes. Such metabolic resistance can be detected by a microplate assay method. Mosquitoes vector resistance can occurs as a result of continuous exposure to the insecticide. Organophosphate insecticide has been used in the vector control program on Anopheles. aconitus, the malaria vector in Jepara Regency since 1983. The use of organophosphate and carbamate insecticides for five years for controlling Anopheles nigerrimus in Srilanka contribute to the selective resistance. This could happen to the population of An. aconitus in Jepara Regency. The objectives of this studies was to determine the potency of An. aconitus from Jepara Regency to be resistant to organophosphate insecticide related to esterase activity mechanism. The study methods used was biochemical assays (microplate assays )for elevated esterase. The level of esterases in larvae was determined using a and b naphthyl acetate, as the substrate andFast Blue B as the coupling reagent. The esterase activity was measured at 450 nm with Dytech ELISA plate reader. Microplate assay (Biochemical assays) on individual An. aconitus from Mlonggo II and Bangsri III subdistrics revealed that 12,9% and 28,6% population was resistant to organophosphate insecticide. The result showed that there was significant difference of elevated of esterase activity with both a and b naphthylacetate substrate hydrolysis, which appeared to be the major resistance mechanism in this multiple organophosphate resistant strain. Therefore the use of another insecticide group for vector control (An. aconitus) was suggested.

Pyrethroid and organophosphate insecticides have been used for more than 20 years worldwide to control a variety of insect pest in different settings. These pesticides have been detected in a variety of environmental samples, including surface waters and sediments and therefore there is significant concern about their potential toxic effects on non-target organisms. Mixtures of compounds from these groups of pesticides have been found to frequently show enhanced toxicity but it has been a challenge to predict whether or not enhanced toxicity will occur for a given combination of compounds. This study therefore studied the effects of binary pyrethroid-organophosphate mixtures using cypermethrin, deltamethrin and dimethoate in an acute toxicity test system with Oreochromis niloticus. The 96 h LC50s for individual insecticides were 9.13 µg/l, 9.42 µg/l and 45.52 mg/l for cypermethrin, deltamethrin and dimethoate respectively. These showed that the pyrethroid insecticides were highly toxic to Oreochromis niloticus and were far more toxic than dimethoate. All mixtures were also more toxic than single insecticides throughout the concentration-response curve with mixtures resulting in mortality at concentrations which the individual pesticides in the mixture were below their respective NOECs. In addition, observed mixture toxicities deviated from the predicted mixture effects based either on the Concentration Addition (CA) or Independent Action (IA) models independent of mixture ratio. However, the extent of observed mixture mortality deviation was dependent on the effect level. Significant deviations (MDR > 2.0) were observed at lower concentrations indicating synergistic effects at lower and possibly environmentally relevant concentrations. This is not unexpected since organophosphate insecticides are known to inhibit acetylcholinesterase as well as inactivate esterase, resulting in reduced detoxification of pyrethroid insecticides and consequently greater toxicity than would be expected. This has important implications for risk assessment of mixtures since the risk of pyrethroid-organophosphate mixtures may be underestimated if either the CA or IA model is employed.

Until now, no research has been carried out in Croatia into consumer preferences for a particular agricultural and food product by a choice experiment. Therefore, little data are available about Croatian consumers' preferences for social concerns (sustainability, biodiversity, rural development and animal welfare) with regard to the consumer choice and behavior favoring local pig breeds, in this case the Black Slavonian Pig breed. A survey was the method used to collect the data, and a survey questionnaire was used as an instrument. The survey was performed on a sample of n = 100 Croatian consumers surveyed online using a hypothetical choice experiment. The data were analyzed using the three logit models: a multinomial logit model (MNL), random parameter logit (RPL), and an error component random parameter logit model (RPL-EC) in order to examine the consumers’ heterogeneous preferences for fresh ham meat of the Black Slavonian Pig. The results suggest that the Croatian consumers appreciated a darker red fresh pork meat than the one obtained from the Black Slavonian Pig reared outdoors and semi-outdoor. They also prefer a fresh meat bearing a geographical information label, such as the continental Croatia and continental Croatia + PDO, to a fresh meat without a label.

The susceptibility of Anopheles albimanus to organophosphates, carbamates and pyrethroid insecticides was unknown in the Panama communities of Aguas Claras, Pintupo and Puente Bayano, located in the Amerindian Reservation of Madungandi. This region is considered a malaria transmission area, where An. albimanus is the main vector. The resistance to organophosphate insecticides, carbamates and pyrethroids was evaluated in field populations of the Anopheles albimanus in Panama. Progeny of An. albimanus collected in three localities in the indigenous Madugandi region were exposed to bioassays of susceptibility to organophosphate insecticides (fenitrothion, malathion and chlorpyrifos), the carbamate (propoxur) and pyrethroids (deltamethrin, lambdacyhalothrin, cyfluthrin and cypermethrin). The protocols were in accordance with those established for adult mosquitoes by World Health Organization. The three strains of the An. albimanus were resistant to the pyrethroid insecticides deltamethrin, lambdacyhalothrin, cyfluthrin and cypermethrin. Susceptibility remained for the organophosphate insecticides fenitrothion, malathion, chlorpyrifos, and the carbamate insecticide propoxur. The results provided important information to the vector control program, contributing to the application of new strategies on the use of insecticides, and thereby lengthening the life of the insecticide in use.

Use of agrochemicals, including insecticides, is vital to food production and predicted to increase 2–5 fold by 2050. Previous studies have shown a positive association between agriculture and the human infectious disease schistosomiasis, which is problematic as this parasitic disease infects approximately 250 million people worldwide. Certain insecticides might runoff fields and be highly toxic to invertebrates, such as prawns in the genus Macrobrachium, that are biocontrol agents for snails that transmit the parasites causing schistosomiasis. We used a laboratory dose-response experiment and an observational field study to determine the relative toxicities of three pyrethroid (esfenvalerate, λ-cyhalothrin, and permethrin) and three organophosphate (chlorpyrifos, malathion, and terbufos) insecticides to Macrobrachium prawns. In the lab, pyrethroids were consistently several orders of magnitude more toxic than organophosphate insecticides, and more likely to runoff fields at lethal levels according to modeling data. At 31 water contact sites in the lower basin of the Senegal River where schistosomiasis is endemic, we found that Macrobrachium prawn survival was associated with pyrethroid but not organophosphate application rates to nearby crop fields after controlling for abiotic and prawn-level factors. Our laboratory and field results suggest that widely used pyrethroid insecticides can have strong non-target effects on Macrobrachium prawns that are biocontrol agents where 400 million people are at risk of human schistosomiasis. Understanding the ecotoxicology of high-risk insecticides may help improve human health in schistosomiasis-endemic regions undergoing agricultural expansion.

Listeria monocytogenes, a foodborne pathogen, exhibits high adaptability to adverse environmental conditions and is common in the food industry, especially in ready-to-eat foods. L. monocytogenes strains pose food safety challenges due to their ability to form biofilms, increased resistance to disinfectants, and long-term persistence in the environment. The aim of this study was to evaluate the presence and genetic diversity of L. monocytogenes in food and related environmental products collected from 2014 to 2022 and assess antibiotic susceptibility and biofilm formation abilities. L. monocytogenes was identified in 13 out of the 227 (6%) of samples, 7 from food products (meat preparation, cheeses, and raw milk) and 6 from food-processing environments (slaughterhouse-floor and catering establishments). All isolates exhibited high biofilm-forming capacity and antibiotic susceptibility testing showed resistance to several classes of antibiotics, especially trimethoprim-sulfamethoxazole and erythromycin. Genotyping and core-genome clustering identified eight sequence types and a cluster of three very closely related ST3 isolates (all from food), suggesting a common contamination source. Whole-genome sequencing (WGS) analysis revealed resistance genes conferring resistance to fosfomycin (fosX), lincosamides (lin), fluoroquinolones (norB), and tetracycline (tetM). In addition, the qacJ gene was also detected, conferring resistance to disinfecting agents and antiseptics. Virulence gene profiling revealed the presence of 92 associated genes associated with pathogenicity, adherence, and persistence. These findings underscore the presence of L. monocytogenes strains in food products and food-associated environments, demonstrating a high virulence of these strains associated with resistance genes to antibiotics, but also to disinfectants and antiseptics. Moreover, they emphasize the need for continuous surveillance, effective risk assessment, and rigorous control measures to minimize the public health risks associated to severe infections, particularly listeriosis outbreaks. A better understanding of the complex dynamics of pathogens in food products and their associated environments can help improve overall food safety and develop more effective strategies to prevent severe health consequences and economic losses.

This research was designed to evaluate responses by Banks grass mite, Oligonychus pratensis (Banks), and twospotted spider mite, TetranychuS urticae Koch, to insecticides alone and in different combinations using 24-h vial bioassays. The twospotted spider mite was more tolerant to many insecticides than the Banks grass mite. Amitraz and S, S, S-tributyl phosphorotrithioate (DEF) synergized 2 organophosphorous insecticides, diazinon and dimethoate, and the pyrethroid bifenthrin against the Banks grass mite. Piperonyl but oxide (PB) antagonized the miticidal activity of esfenvalerate against the Banks grass mite. In contrast to twospotted spider mites, amitraz did not synergize the organophosphorous insecticides, and piperonyl butoxide was a good synergist of the pyrethroid esfenvalerate (98.3-fold increase). DEF synergized bifenthrin and dimethoate against the twospotted spider mite. Mixtures of organophosphorous + pyrethroid mixtures were generally better for twospotted spider mites than Banks grass mites. Insecticide toxicity of the organophosphorous + pyrethroid mixtures was increased from 2.3 to 18.2 times. The synergistic and antagonistic activity of the insecticide + synergist mixtures and organophosphorous + pyrethroid mixtures resulted in twos potted spider mites being less tolerant to several mixtures than were the Banks grass mites. A 3-chemical mixture of dimethoate and bifenthrin with amitraz or piperonyl butoxide caused 52.7- and 94.7-fold increases in toxicity against the twospotted spider mite. The synergistic activity by the chemical mixtures suggest that metabolic degradation and target site insensitivity may be involved in twospotted spider mite resistance. Further studies are needed to improve our understanding of the specific mechanisms in each spider mite species for each organophosphorous and pyrethroid insecticide. The proper insecticide mixture may be an effective tool for managing Banks grass mite and twospotted spider mite infestations.

Studies on the water balance mechanism of the tick, Boophilus microplus canestrini

A range of pesticides are available in Australia for use in agricultural and domestic settings to control pests, including organophosphate and pyrethroid insecticides, herbicides, and insect repellents, such as N,N-diethyl-meta-toluamide (DEET). The aim of this study was to provide a cost-effective preliminary assessment of background exposure to a range of pesticides among a convenience sample of Australian residents. De-identified urine specimens stratified by age and sex were obtained from a community-based pathology laboratory and pooled (n=24 pools of 100 specimens). Concentrations of urinary pesticide biomarkers were quantified using solid-phase extraction coupled with isotope dilution high-performance liquid chromatography-tandem mass spectrometry. Geometric mean biomarker concentrations ranged from <0.1 to 36.8ng/mL for organophosphate insecticides, <0.1 to 5.5ng/mL for pyrethroid insecticides, and <0.1 to 8.51ng/mL for all other biomarkers with the exception of the DEET metabolite 3-diethylcarbamoyl benzoic acid (4.23 to 850ng/mL). We observed no association between age and concentration for most biomarkers measured but noted a "U-shaped" trend for five organophosphate metabolites, with the highest concentrations observed in the youngest and oldest age strata, perhaps related to age-specific differences in behavior or physiology. The fact that concentrations of specific and non-specific metabolites of the organophosphate insecticide chlorpyrifos were higher than reported in USA and Canada may relate to differences in registered applications among countries. Additional biomonitoring programs of the general population and focusing on vulnerable populations would improve the exposure assessment and the monitoring of temporal exposure trends as usage patterns of pesticide products in Australia change over time.