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Environmental Research Oct 2023Synthetic pesticides (e.g. herbicides, fungicides and insecticides) are used widely in agriculture to protect crops from pests, weeds and disease. However, their use... (Review)
Review
Synthetic pesticides (e.g. herbicides, fungicides and insecticides) are used widely in agriculture to protect crops from pests, weeds and disease. However, their use also comes with a range of environmental concerns. One key concern is the effect of insecticides on non-target organisms such as bees, who provide pollination services for crops and wild plants. This systematic literature review quantifies the existing research on bees and insecticides broadly, and then focuses more specifically on non-neonicotinoid insecticides and non-honeybees. We find that articles on honeybees (Apis sp.) and insecticides account for 80% of all research, with all other bees combined making up 20%. Neonicotinoids were studied in 34% of articles across all bees and were the most widely studied insecticide class for non-honeybees overall, with almost three times as many studies than the second most studied class. Of non-neonicotinoid insecticide classes and non-honeybees, the most studied were pyrethroids and organophosphates followed by carbamates, and the most widely represented bee taxa were bumblebees (Bombus), followed by leaf-cutter bees (Megachile) and mason bees (Osmia). Research has taken place across several countries, with the highest numbers of articles from Brazil and the US, and with notable gaps from countries in Asia, Africa and Oceania. Mortality was the most studied effect type, while sub-lethal effects such as on behaviour were less studied. Few studies tested how the effect of insecticides were influenced by multiple pressures, such as climate change and co-occurring pesticides (cocktail effects). As anthropogenic pressures do not occur in isolation, we suggest that future research also addresses these knowledge gaps. Given the changing global patterns in insecticide use, and the increasing inclusion of both non-honeybees and sub-lethal effects in pesticide risk assessment, there is a need for expanding research beyond its current state to ensure a strong scientific evidence base for the development of risk assessment and associated policy.
Topics: Bees; Animals; Insecticides; Neonicotinoids; Pesticides; Pyrethrins; Fungicides, Industrial; Crops, Agricultural
PubMed: 37454798
DOI: 10.1016/j.envres.2023.116612 -
The Cochrane Database of Systematic... Feb 2018Malaria is an important cause of illness and death across endemic regions. Considerable success against malaria has been achieved within the past decade mainly through... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Malaria is an important cause of illness and death across endemic regions. Considerable success against malaria has been achieved within the past decade mainly through long-lasting insecticide-treated nets (LLINs). However, elimination of the disease is proving difficult as current control methods do not protect against mosquitoes biting outdoors and when people are active. Repellents may provide a personal protection solution during these times.
OBJECTIVES
To assess the impact of topical repellents, insecticide-treated clothing, and spatial repellents on malaria transmission.
SEARCH METHODS
We searched the following databases up to 26 June 2017: the Cochrane Infectious Diseases Group Specialized Register; the Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library; MEDLINE; Embase; US AFPMB; CAB Abstracts; and LILACS. We also searched trial registration platforms and conference proceedings; and contacted organizations and companies for ongoing and unpublished trials.
SELECTION CRITERIA
We included randomized controlled trials (RCTs) and cluster-randomized controlled trials of topical repellents proven to repel mosquitoes; permethrin-treated clothing; and spatial repellents such as mosquito coils. We included trials that investigated the use of repellents with or without LLINs, referred to as insecticide-treated nets.
DATA COLLECTION AND ANALYSIS
Two review authors independently reviewed trials for inclusion, extracted the data, and assessed the risk of bias. A third review author resolved any discrepancies. We analysed data by conducting meta-analysis and stratified by whether the trials had included LLINs. We combined results from cRCTs with individually RCTs by adjusting for clustering and presented results using forest plots. We used GRADE to assess the certainty of the evidence.
MAIN RESULTS
Eight cRCTs and two RCTs met the inclusion criteria. Six trials investigated topical repellents, two trials investigated insecticide-treated clothing, and two trials investigated spatial repellents.Topical repellentsSix RCTS, five of them cluster-randomized, investigated topical repellents involving residents of malaria-endemic regions. Four trials used topical repellents in combination with nets, but two trials undertaken in displaced populations used topical repellents alone. It is unclear if topical repellents can prevent clinical malaria (RR 0.65, 95% CI 0.4 to 1.07, very low certainty evidence) or malaria infection (RR 0.84, 95% CI 0.64 to 1.12, low-certainty evidence) caused by P. falciparum. It is also unclear if there is any protection against clinical cases of P. vivax (RR 1.32, 95% CI 0.99 to 1.76, low-certainty evidence) or incidence of infections (RR 1.07, 95% CI 0.80 to 1.41, low-certainty evidence). Subgroup analysis of trials including insecticide-treated nets did not show a protective effect of topical repellents against malaria. Only two studies did not include insecticide-treated nets, and they measured different outcomes; one reported a protective effect against clinical cases of P. falciparum (RR 0.40, 95% CI 0.23 to 0.71); but the other study measured no protective effect against malaria infection incidence caused by either P. falciparum or P. vivax.Insecticide-treated clothingInsecticide-treated clothing were investigated in trials conducted in refugee camps in Pakistan and amongst military based in the Colombian Amazon. Neither study provided participants with insecticide-treated nets. In the absence of nets, treated clothing may reduce the incidence of clinical malaria caused by P. falciparum by approximately 50% (RR 0.49, 95% CI 0.29 to 0.83, low-certainty evidence) and P. vivax (RR 0.64, 95% CI 0.40 to 1.01, low-certainty evidence).Spatial repellentsTwo cluster-randomized RCTs investigated mosquito coils for malaria prevention. We do not know the effect of spatial repellents on malaria prevention (RR 0.24, 95% CI 0.03 to 1.72, very low certainty evidence). There was large heterogeneity between studies and one study had high risk of bias.
AUTHORS' CONCLUSIONS
There is insufficient evidence to conclude topical or spatial repellents can prevent malaria. There is a need for better designed trials to generate higher certainty of evidence before well-informed recommendations can be made. Adherence to daily compliance remains a major limitation. Insecticide-treated clothing may reduce risk of malaria infection in the absence of insecticide-treated nets; further studies on insecticide-treated clothing in the general population should be done to broaden the applicability of the results.
Topics: Animals; Culicidae; Incidence; Insect Repellents; Insecticide-Treated Bednets; Malaria, Falciparum; Malaria, Vivax; Protective Clothing; Randomized Controlled Trials as Topic
PubMed: 29405263
DOI: 10.1002/14651858.CD011595.pub2 -
Environmental Health : a Global Access... Nov 2023Early life exposure to lead, mercury, polychlorinated biphenyls (PCBs), polybromide diphenyl ethers (PBDEs), organophosphate pesticides (OPPs), and phthalates have been... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Early life exposure to lead, mercury, polychlorinated biphenyls (PCBs), polybromide diphenyl ethers (PBDEs), organophosphate pesticides (OPPs), and phthalates have been associated with lowered IQ in children. In some studies, these neurotoxicants impact males and females differently. We aimed to examine the sex-specific effects of exposure to developmental neurotoxicants on intelligence (IQ) in a systematic review and meta-analysis.
METHOD
We screened abstracts published in PsychINFO and PubMed before December 31st, 2021, for empirical studies of six neurotoxicants (lead, mercury, PCBs, PBDEs, OPPs, and phthalates) that (1) used an individualized biomarker; (2) measured exposure during the prenatal period or before age six; and (3) provided effect estimates on general, nonverbal, and/or verbal IQ by sex. We assessed each study for risk of bias and evaluated the certainty of the evidence using Navigation Guide. We performed separate random effect meta-analyses by sex and timing of exposure with subgroup analyses by neurotoxicant.
RESULTS
Fifty-one studies were included in the systematic review and 20 in the meta-analysis. Prenatal exposure to developmental neurotoxicants was associated with decreased general and nonverbal IQ in males, especially for lead. No significant effects were found for verbal IQ, or postnatal lead exposure and general IQ. Due to the limited number of studies, we were unable to analyze postnatal effects of any of the other neurotoxicants.
CONCLUSION
During fetal development, males may be more vulnerable than females to general and nonverbal intellectual deficits from neurotoxic exposures, especially from lead. More research is needed to examine the nuanced sex-specific effects found for postnatal exposure to toxic chemicals.
Topics: Child; Pregnancy; Humans; Male; Female; Polychlorinated Biphenyls; Lead; Sex Characteristics; Halogenated Diphenyl Ethers; Mercury; Insecticides; Organophosphorus Compounds; Prenatal Exposure Delayed Effects
PubMed: 37978510
DOI: 10.1186/s12940-023-01029-z -
Environmental Health Perspectives Nov 2023Evidence of the negative impacts of contemporary use insecticides on sperm concentration has increased over the last few decades; however, meta-analyses on this topic... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Evidence of the negative impacts of contemporary use insecticides on sperm concentration has increased over the last few decades; however, meta-analyses on this topic are rare.
OBJECTIVES
This investigation assessed the qualitative and quantitative strength of epidemiological evidence regarding adult exposure to two classes of contemporary use insecticides-organophosphates (OPs) and -methyl carbamates (NMCs)-and sperm concentration using robust and reproducible systematic review and meta-analysis methods.
METHODS
Three scientific databases (PubMed, Scopus, and Web of Science), two U.S. government databases (NIOSHTIC-2 and Science.gov), and five nongovernmental organization websites were searched for relevant primary epidemiological studies published in any language through 11 August 2022. Risk of bias and strength of evidence were evaluated according to Navigation Guide systematic review methodology. Bias-adjusted standardized mean difference effect sizes were calculated and pooled using a three-level, multivariate random-effect meta-analysis model with cluster-robust variance estimation.
RESULTS
Across 20 studies, 21 study populations, 42 effect sizes, and 1,774 adult men, the pooled bias-adjusted standardized mean difference in sperm concentration between adult men more- and less-exposed to OP and NMC insecticides was (95% CI: , ; ). Sensitivity and subgroup analyses explored statistical heterogeneity and validated the model robustness. Although the pooled effect estimate was modified by risk of bias, insecticide class, exposure setting, and recruitment setting, it remained negative in direction across all meta-analyses. The body of evidence was rated to be of moderate quality, with sufficient evidence of an association between higher adult OP and NMC insecticide exposure and lower sperm concentration.
DISCUSSION
This comprehensive investigation found sufficient evidence of an association between higher OP and NMC insecticide exposure and lower sperm concentration in adults. Although additional cohort studies can be beneficial to fill data gaps, the strength of evidence warrants reducing exposure to OP and NMC insecticides now to prevent continued male reproductive harm. https://doi.org/10.1289/EHP12678.
Topics: Humans; Male; Adult; Insecticides; Organophosphates; Semen; Carbamates; Spermatozoa
PubMed: 37966213
DOI: 10.1289/EHP12678 -
Medical Sciences (Basel, Switzerland) Apr 2018Nowadays, there seems to be a consensus about the multifactorial nature of autism spectrum disorders (ASD). The literature provides hypotheses dealing with numerous... (Review)
Review
Nowadays, there seems to be a consensus about the multifactorial nature of autism spectrum disorders (ASD). The literature provides hypotheses dealing with numerous environmental factors and genes accounting for the apparently higher prevalence of this condition. Researchers have shown evidence regarding the impact of gut bacteria on neurological outcomes, altering behavior and potentially affecting the onset and/or severity of psychiatric disorders. Pesticides and agrotoxics are also included among this long list of ASD-related environmental stressors. Of note, ingestion of glyphosate (GLY), a broad-spectrum systemic herbicide, can reduce beneficial bacteria in the gastrointestinal tract microbiota without exerting any effects on the Clostridium population, which is highly resistant to this herbicide. In the present study, (i) we performed a systematic review to evaluate the relationship between Clostridium bacteria and the probability of developing and/or aggravating autism among children. For that purpose, electronic searches were performed on and databases for identification of relevant studies published in English up to December 2017. Two independent researches selected the studies and analyzed the data. The results of the present systematic review demonstrate an interrelation between Clostridium bacteria colonization of the intestinal tract and autism. Finally, (ii) we also hypothesize about how environmental GLY levels may deleteriously influence the gut-brain axis by boosting the growth of Clostridium bacteria in autistic toddlers.
PubMed: 29617356
DOI: 10.3390/medsci6020029 -
European Review For Medical and... Apr 2021It is biologically plausible that occupational and environmental pesticide exposure may contribute to breast cancer risk. Persistent chemical compounds, such as...
OBJECTIVE
It is biologically plausible that occupational and environmental pesticide exposure may contribute to breast cancer risk. Persistent chemical compounds, such as pesticides, tend to be lipophilic and are detected in human breast milk and adipose tissue. Therefore, the present systematic review aims to clarify the gender difference in breast cancer concerning pesticide exposure.
MATERIALS AND METHODS
A total of 70 studies satisfied the inclusion criteria and were included in the systematic review.
RESULTS
From the studies analyzed, it was observed that exposure to pesticides could be a risk factor for breast cancer in women, in particular in young women and in women who experienced menarche at a young age. In contrast, no association was found for breast cancer in men. Female breast cancer is correlated with estrogen receptor-negative tumor characteristics. Breast cancer in men was no correlated with pesticide exposure.
CONCLUSIONS
Breast cancer in women has been linked to estrogen receptor positivity, but this positivity appears to be inversely related to fertility. The estrogen-like effects of organochlorine pesticides could be the cause of the observed gender differences.
Topics: Breast Neoplasms; Environmental Exposure; Female; Humans; Hydrocarbons, Chlorinated; Male; Pesticides; Risk Factors; Sex Characteristics
PubMed: 33877654
DOI: 10.26355/eurrev_202104_25543 -
International Journal of Pediatrics 2023Neural tube defects are a type of congenital anomaly caused by an abnormality in the development of the brain and spinal cord during embryogenesis. They cause high rates... (Review)
Review
BACKGROUND
Neural tube defects are a type of congenital anomaly caused by an abnormality in the development of the brain and spinal cord during embryogenesis. They cause high rates of mortality, morbidity, and lifelong disability. There are several studies carried out worldwide reporting different findings on the burden and associated factors. The aim of this study is to carry out a systematic review and meta-analysis of the burden of neural tube defects and their associated factors in Africa.
METHODS
A total of 58 eligible articles were identified systematically using databases such as PubMed, Embase, African Journal Online Library, ProQuest, Cochrane, Google Scopus, Google Scholar, and Grey literature. Extracted data were analyzed using STATA 16.0 statistical software. The heterogeneity of studies was determined using the Cochrane Q test statistic and test statistics with forest plots. A random effects model was used to examine the pooled burden of neural tube defects, subgroups of the region, subtypes of NTDs, sensitivity analysis, and publication bias. The association between NTDs and associated factors was studied using a fixed-effect model.
RESULTS
Fifty-eight studies with a total of 7,150,654 participants in 16 African countries revealed that the pooled burden of neural tube defects was 32.95 per 10,000 births (95% CI: 29.77-36.13). The Eastern African region had the highest burden in the subgroup analysis, with 111.13 per 10,000 births (95% CI: 91.85-130.42). South African countries had the lowest burden, at 11.43 per 10,000 births (95% CI: 7.51-15.34). In subtype analysis, spina bifida had the highest pooled burden at 17.01 per 10,000 births (95 percent CI: 15.00-19.00), while encephalocele had the lowest at 1.66 per 10,000 births (95% CI: 1.12-2.20). Maternal folic acid supplementation (AOR: 0.38; 95% CI: 0.16-0.94), alcohol consumption (AOR: 2.54; 95% CI: 1.08-5.96), maternal age (AOR: 3.54; 95% CI: 1.67-7.47), pesticide exposure (AOR: 2.69; 95% CI: 1.62-4.46), X-ray radiation (AOR: 2.67; 95% CI: 1.05-6.78), and history of stillbirth (AOR: 3.18; 95% CI: 1.11-9.12) were significantly associated with NTDs.
CONCLUSION
The pooled burden of NTDs in Africa was found to be high. Maternal age, alcohol consumption, pesticide and X-ray radiation exposure, history of stillbirth, and folic acid supplementation were significantly associated with NTDs.
PubMed: 37388625
DOI: 10.1155/2023/9635827 -
Scandinavian Journal of Work,... May 2017Objectives We conducted a systematic literature review to identify studies fulfilling good scientific epidemiological standards for use in meta-analyses of relevant risk... (Meta-Analysis)
Meta-Analysis Review
Objectives We conducted a systematic literature review to identify studies fulfilling good scientific epidemiological standards for use in meta-analyses of relevant risk factors for Parkinson's disease. Methods Our search identified 103 original publications on associations between work and Parkinson's disease. GRADE guidelines were used to ensure high scientific quality, and reliable guidelines were applied to classify the papers. Of the 103 articles, 47 fulfilled good scientific standards while 56 were methodologically deficient and thus excluded from our meta-analyses. Results A total of 23 publications concerned work exposure to pesticides. The weighted relative risk estimate was 1.67 (95% confidence interval 1.42-1.97). A funnel plot and bias test indicated that some publication bias concerning smaller studies might have been present. The risk estimate was not influenced by study design (case-control, cohort, or cross-sectional study) or gender. Higher estimates were found when there was a hereditary taint or onset below age 60. Studies on exposure to metals or electromagnetic fields did not show increased risk. Conclusions Using an elaborated quality protocol, there is now strong evidence that exposure to any pesticide involves a ≥50% increased risk for developing Parkinson's disease.
Topics: Humans; Occupational Exposure; Parkinson Disease; Pesticides; Risk Factors
PubMed: 28379585
DOI: 10.5271/sjweh.3641 -
Environmental Health Perspectives Sep 2017The prevalence of obesity is increasing in all countries, becoming a substantial public health concern worldwide. Increasing evidence has associated obesity with... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The prevalence of obesity is increasing in all countries, becoming a substantial public health concern worldwide. Increasing evidence has associated obesity with persistent pollutants such as the pesticide DDT and its metabolite '-DDE.
OBJECTIVES
Our objective was to systematically review the literature on the association between exposure to the pesticide DDT and its metabolites and obesity to develop hazard identification conclusions.
METHODS
We applied a systematic review-based strategy to identify and integrate evidence from epidemiological, , and studies. The evidence from prospective epidemiological studies was quantitatively synthesized by meta-analysis. We rated the body of evidence and integrated the streams of evidence to systematically develop hazard identification conclusions.
RESULTS
We identified seven epidemiological studies reporting prospective associations between exposure to -DDE and adiposity assessed by body mass index (BMI) -score. The results from the meta-analysis revealed positive associations between exposure to -DDE and BMI -score (β=0.13 BMI -score (95% CI: 0.01, 0.25) per log increase of -DDE). Two studies constituted the primary evidence. Both studies reported positive associations between exposure to -DDT and increased adiposity in rodents. We identified 19 studies and 7 studies that supported the biological plausibility of the obesogenic effects of -DDT and -DDE.
CONCLUSIONS
We classified -DDT and -DDE as "presumed" to be obesogenic for humans, based on a moderate level of primary human evidence, a moderate level of primary evidence, and a moderate level of supporting evidence from and studies. https://doi.org/10.1289/EHP527.
Topics: DDT; Dichlorodiphenyl Dichloroethylene; Environmental Exposure; Environmental Pollutants; Humans; Obesity
PubMed: 28934091
DOI: 10.1289/EHP527 -
Toxics Aug 2023Exposure to pesticides in Arab countries is a significant public health concern due to extensive agricultural activity and pesticide use. This systematic review aimed to... (Review)
Review
Exposure to pesticides in Arab countries is a significant public health concern due to extensive agricultural activity and pesticide use. This systematic review aimed to evaluate the genotoxic effects of agricultural pesticide exposure in the region, identify research gaps, and assess methodological limitations. Following the PRISMA guidelines, a comprehensive search yielded five relevant studies conducted in Egypt, Syria, and Jordan. Various genotoxicity assays were employed, revealing a higher level of DNA damage in exposed compared to non-exposed individuals. Farmers exposed to pesticides exhibited a significantly higher occurrence of chromosomal translocation (t(14;18)), micronuclei, and chromosomal aberrations. However, only two studies assessed cytotoxicity indirectly. The studies predominantly focused on male participants, with variations in sample size and pesticide types. The lack of detailed exposure data necessitates cautious interpretation. This review underscores the need for further research on the genotoxicity of occupational pesticide exposure in the Middle East. Future studies should adopt robust study designs, collect biological and environmental samples, conduct repeated sampling, analyze seasonal variations, and encompass diverse study sites associated with specific crop groups.
PubMed: 37624167
DOI: 10.3390/toxics11080663