A review of pesticide exposure and cancer incidence in the Agricultural Health Study cohort

A Scientific Review of Pesticides: Classification, Toxicity, Health Effects, Sustainability, and Environmental Impact

Over the years, the use of pesticides has risen significantly, primarily to combat undesirable organisms that threaten crucial crops. A variety of pesticides are available, each designed to protect crops from specific threats like fungi, bacteria, and other pests. Other than crop protection, pesticides are also used in controlling insect vector-borne diseases like malaria and Lyme disease in humans. However, the application of these pesticides must be carefully measured and managed to prevent adverse effects on humans, non-target animals, and the environment. This review delves into the detailed classification of pesticides, exploring their mechanisms of action, applications, benefits, and potential side effects. Understanding the different categories of pesticides, such as herbicides, insecticides, fungicides, rodenticides, and biopesticides, helps us comprehend how each function to control pests. Additionally, we discuss the advantages of pesticide use, including increased crop yields and the prevention of crop diseases, which contribute to food security and agricultural productivity. This review also addresses the significant concerns related to pesticide usage, such as the development of pest resistance, health risks to humans through exposure and residues in food, as well as the impact on biodiversity and ecosystems. The review emphasizes the importance of using pesticides responsibly and implementing integrated pest management strategies to mitigate this risk of exposure. By providing a comprehensive overview of pesticide classification, mechanisms of action, and implications, this review aims to inform and guide us to the safe and effective use of pesticides for daily agricultural practices.

Chemical contaminants in blood and their implications in chronic diseases

Artificial chemical products are widely used and ubiquitous worldwide and pose a threat to the environment and human health. Accumulating epidemiological and toxicological evidence has elucidated the contributions of environmental chemical contaminants to the incidence and development of chronic diseases that have a negative impact on quality of life or may be life-threatening. However, the pathways of exposure to these chemicals and their involvements in chronic diseases remain unclear. We comprehensively reviewed the research progress on the exposure risks of humans to environmental contaminants, their body burden as indicated by blood monitoring, and the correlation of blood chemical contaminants with chronic diseases. After entering the human body through various routes of exposure, environmental contaminants are transported to target organs through blood circulation. The application of the modern analytical techniques based on human plasma or serum specimens is promising for determining the body burden of environmental contaminants, including legacy persistent organic pollutants, emerging pollutants, and inorganic elements. Furthermore, their body burden, as indicated by blood monitoring correlates with the incidence and development of metabolic syndromes, cancers, chronic nervous system diseases, cardiovascular diseases, and reproductive disorders. On this basis, we highlight the urgent need for further research on environmental pollution causing health problems in humans.

Exposure to pesticides and risk of colorectal cancer: A systematic review and meta-analysis

Colorectal cancer (CRC) is a widespread malignancy worldwide, and its relationship with pesticide exposure remains inconclusive. This study aims to elucidate the relationship between pesticide exposure and the risk of colon, rectal, or CRC, focusing on specific pesticide groups. We conducted an extensive literature search for peer-reviewed studies published up to March 31, 2023. Summary risk ratios (RR) and their corresponding 95% confidence intervals (CI) were calculated using stratified random-effects meta-analyses, taking into account different types of exposure and outcomes, and various exposed populations and pesticide subgroups. This approach aimed to address the substantial heterogeneity observed across the literature. We also assessed heterogeneity and potential small-study effects to ensure the robustness of our findings. From the 50 studies included in this review, 33 contributed to the meta-analysis. Our results indicate a significant association between herbicide exposure and colon cancer in both lifetime-days (LDs) (RR = 1.20; 95% CI = 1.01-1.42) and intensity-weighted lifetime-days (IWLDs) (RR = 1.29, 95% CI = 1.12-1.49) exposure. Similarly, insecticide exposure was associated with an increased risk of colon cancer in IWLDs (RR = 1.32; 95% CI = 1.02-1.70) exposure, and rectal cancer in any versus never exposure (RR = 1.21; 95% CI = 1.07-1.36), IDs (RR = 1.86; 95% CI = 1.30-2.67) and IWLDs (RR = 1.70; 95% CI = 1.03-2.83) exposure. While these findings suggest significant associations of herbicide and insecticide exposure with colon and rectal cancer, respectively, further research is needed to explore the impact of other pesticide groups and deepen our understanding of pesticide exposure. These results have important implications for policymakers and regulators, underscoring the need for stricter supervision and regulation of pesticide use to mitigate CRC risk.

The occurrence of bone and joint cancers and their association with rural living and radon exposure in Iowa

Primary bone and joint cancers are rare and understudied, yet these neoplasms are difficult to treat and impact all age groups. To explore the long-term changes in the occurrence of bone and joint cancers, patients diagnosed with these neoplasms between 1975 and 2016 were identified in the Surveillance Epidemiology and End Results of the National Cancer Institute of the USA. The age-adjusted incidence (AAIR) and mortality (AAMR) rates were calculated for three decades and compared to AAIR and AAMR in years 1975-1984. By using the population-based cancer registries of the USA, Iowa was identified as a state with increased cases of bone and joint malignancies. The bone and joint cancer cases in Iowa were correlated with the percentage of rural population, the average farmland size, or the residential radon levels. Results demonstrated that the mean AAIR of bone and joint cancers for US female and male patients (< 50 years of age) increased from 0.57 (95% C.I. 0.55-0.63) and 0.76 (95% C.I. 0.69-0.82) for years 1975-1984 to 0.71 (95% C.I. 0.66-0.76) and 0.94 (95% C.I. 0.87-1.07) for years 2005-2014, respectively. The increase in bone and joint cancer cases in Iowa positively correlated with the percentage rural population (R = 0.222, P < 0.02), and the average farmland size (R = 0.236, P < 0.02) but not the radon levels (R = - 0.038, P < 0.7). The findings revealed that patients younger than 50 years of age and those who resided in rural areas and engaged in farming were more likely to be diagnosed with primary bone and joint cancers.

Situations of work-related diseases and injuries among agriculturists in the upper northeast regions of Thailand

Background: Agriculturists exposed to health hazards are affected by increased occupational disease. This retrospective study aimed to investigate situations of work-related diseases and injuries among agriculturists in upper northeast Thailand. Methods: The secondary data of international classification of diseases 10 th revision (ICD-10) case reports of occupational disease among farmers, from the database of the Health Data Center (HDC), were used. The registered farmers data was collected as a dataset from the provincial agricultural office and the data of ICD-10 code utilised from the hospital information system (HIS) of healthcare services in Udon Thani and Roi-Et provinces, which was extracted for cases of work-related diseases and injuries of registered agriculturists. The annual morbidity rate of occupational diseases was analysed and presented at a rate per 100,000 farmers. Results: Among farmers in the HDC database, lung disease, which was not reported as occupational disease of the HDC database, was the highest ranking of all diseases, followed by work-related musculoskeletal disorders (WMSDs), noise- and heat-related diseases, and pesticide toxicity, respectively, while the injury rate was as high as that of WMSDs. Those morbidity rates of Roi-Et and Udon Thani provinces were representative of the morbidity ranking of diseases of the nation and had increasing trends from 2014 to 2016. The number of farmers in the HDC database did not consistently reflect the number of registered farmers in the agricultural database. Conclusions: Situations of work-related diseases and injuries discovered among registered farmers reflect the health problems of Thai agriculturists, and the underestimation in the reported disease rate in the health database is explained by big data analysis, which showed that work-related cases with an identifying code of Y96 had rarely been reported among agriculturists. Therefore, Thai agriculturists should be supported in registration with occupational diseases and injuries surveillance as holistic healthcare.

Thyroid Carcinoma: A Review for 25 Years of Environmental Risk Factors Studies

Environmental factors are established contributors to thyroid carcinomas. Due to their known ability to cause cancer, exposure to several organic and inorganic chemical toxicants and radiation from nuclear weapons, fallout, or medical radiation poses a threat to global public health. Halogenated substances like organochlorines and pesticides can interfere with thyroid function. Like phthalates and bisphenolates, polychlorinated biphenyls and their metabolites, along with polybrominated diethyl ethers, impact thyroid hormones biosynthesis, transport, binding to target organs, and impair thyroid function. A deeper understanding of environmental exposure is crucial for managing and preventing thyroid cancer. This review aims to investigate the relationship between environmental factors and the development of thyroid cancer.

Occupational factors affecting the decline in pulmonary function among male farmers using occupational pesticide in Gyeonggi-do, South Korea

Background

Occupational pesticide exposure is a potential risk for respiratory health effects. Most clinical studies on pesticide exposure were related to acute exposure, and only a few studies on chronic exposure have been conducted. This study investigated the chronic respiratory health status and the chronic effects of occupational pesticide exposures of farmers in Gyeonggi-do.

Methods

Surveys and pulmonary function tests were conducted on 1,697 farmers in 16 regions of Gyeonggi-do. The structured questionnaire included demographic characteristics, medical history, recent respiratory symptoms and diseases, and work-related conditions, and was conducted through one-on-one interviews. The prevalence of respiratory diseases was compared by the odds ratios (ORs) at 95% confidence intervals (CIs) estimated by logistic regression analysis. Additional multivariate logistic regression analysis was also conducted.

Results

Pesticide work groups showed significant association with an obstructive pattern in the lung function test (unadjusted OR, 2.38; 95% CI, 1.17-5.52). Selected work-related variables of pesticide exposure were 'start age,' 'cumulative duration,' 'mixing pesticides,' and 'protection(goggle).' The obstructive pattern of lung function test showed significant associations with mixing pesticides (OR, 2.30; 95% CI,1.07-5.46), and protection (goggle) use (OR, 0.34; 95% CI, 0.12-0.79).

Conclusions

Mixing two or more pesticides showed a significant association. Wearing goggles can be seen as an indicator of awareness of the protective equipment and proper wearing of protective equipment, and loss of pulmonary function can be prevented when appropriate protection is worn.

Effects of endocrine active contaminating pesticides on RACK1 expression and immunological consequences in THP-1 cells

We have previously demonstrated that RACK1, which expression is under steroid hormone control, plays an important role in the activation of immune cells and its expression can be useful to evaluate the immunotoxic profile of endocrine disrupting chemicals (EDCs). Hence, we investigated the effects of three contaminating and persistent pesticides: the fungicide vinclozolin (VIN), the herbicide atrazine (ATR) and the insecticide cypermethrin (CYP) on RACK1 expression and on innate immune response. VIN resulted in modest alteration of RACK1 while ATR and CYP reduced in a dose dependent manner RACK1 expression, ultimately leading to the decrease in lipopolysaccharide-induced IL-8 and TNF-α release and CD86 and CD54 surface marker expression. Moreover, our data indicate that, after exposure to EDCs, alterations of RACK1 expression can also occur with mechanisms not directly mediated by an interaction with a nuclear or membrane steroid receptors. Therefore, RACK1 could represent a useful EDCs screening tool to evaluate their immunotoxic potential and to dissect their mechanisms of action.

Effects of endocrine disrupting chemicals on the expression of RACK1 and LPS-induced THP-1 cell activation

The existence of a complex hormonal balance among glucocorticoids, androgens and estrogens involved in the regulation of Receptor for Activated C Kinase 1 (RACK1) expression and its related immune cells activation, highlights the possibility to employ this protein as screening tool for the evaluation of the immunotoxic profile of endocrine disrupting chemicals (EDCs), hormone-active substances capable of interfering with the physiologic hormonal signaling. Hence, the aim of this work was to investigate the effect of the exposure of EDCS 17α-ethynylestradiol (EE), diethyl phthalate (DEP) and perfluorooctanesulfonic acid (PFOS) on RACK1 expression and on lipopolysaccharide (LPS)-induced activation of the human monocytic cell line THP-1, a validated model for this investigation. In line with our previous results with estrogen-active compounds, EE treatment significantly induced RACK1 promoter transcriptional activity, mRNA expression, and protein levels, which paralleled an increase in LPS-induced IL-8, TNF-α production and CD86 expression, previously demonstrated to be dependent on RACK1/PKCβ activation. EE mediates its effect on RACK1 expression through G-protein-coupled estrogen receptor (GPER) and androgen receptor (AR) ligand-independent cascade, as also suggested by in silico molecular docking simulation. Conversely, DEP and PFOS induced a dose-dependent downregulation of RACK1 promoter transcriptional activity, mRNA expression, and protein levels, which was mirrored by a reduction of IL-8, TNF-α production and CD86 expression. Mifepristone pre-treatments abolish DEP and PFOS effects, confirming their GR agonist profile, also corroborated by molecular docking. Altogether, our data confirm that RACK1 represents an interesting target of steroid active compounds, which expression offers the opportunity to screen the immunotoxic potential of different hormone-active substances of concerns due to their human exposure and environmental persistence.

Exocrine pancreatic cancer and living near to waste sites containing hazardous organic chemicals, New York State, USA - an 18-year population-based study

OBJECTIVES

The etiology of exocrine pancreatic cancer (EPC) remains unknown except for family history and smoking. Despite recent medical advances, rates of pancreatic cancer incidence and mortality are increasing. Although existing evidence suggests a potentially causal relationship between environmental chemical exposures and pancreatic cancer, whether residential exposure impacts pancreatic cancer rates remains unknown.

MATERIAL AND METHODS

The authors identified 28 941 patients diagnosed with exocrine pancreatic cancer in New York State exclusive of New York City for the years 1996-2013. Descriptive statistics and negative binomial regression were used in this ecological study to compare pancreatic cancer hospitalization rates among patients who lived in zip codes with hazardous waste sites (HWSs) containing persistent organic pollutants (POPs) and volatile organic pollutants (VOCs) compared with clean zip codes with no identified hazardous waste sites. The authors assessed the effect of selected known and suspected human carcinogens on the EPC hospitalization rates by subgroup analyses.

RESULTS

Compared with the clean sites, the pancreatic cancer hospital discharge rate in the "VOCs without POPs" and "VOCs and POPs" sites, after adjustment for potential confounders were 1.06 (95% CI: 1.03-1.09) and 1.05 (95% CI: 1.01-1.08), respectively. In the analysis by specific chemicals, rate ratios (RR) for the benzene (RR = 1.12) and ethylbenzene (RR = 1.34) in the non-chlorinated VOCs group, trichloroethylene (RR = 1.07) and tetrachloroethylene (RR = 1.11) in the chlorinated VOCs group, chlorinated pesticides (RR = 1.11) and PCBs (RR = 1.05) in the POPs groups were statistically significant (p-values <0.05) compared with clean sites.

CONCLUSIONS

Compared with the clean sites, the pancreatic cancer hospital discharge rate in the "VOCs without POPs" and "VOCs and POPs" sites, after adjustment for potential confounders were 1.06 (95% CI: 1.03-1.09) and 1.05 (95% CI: 1.01-1.08), respectively. In the analysis by specific chemicals, rate ratios (RR) for the benzene (RR = 1.12) and ethylbenzene (RR = 1.34) in the non-chlorinated VOCs group, trichloroethylene (RR = 1.07) and tetrachloroethylene (RR = 1.11) in the chlorinated VOCs group, chlorinated pesticides (RR = 1.11) and PCBs (RR = 1.05) in the POPs groups were statistically significant (p-values <0.05) compared with clean sites. Int J Occup Med Environ Health. 2022;35(4):459-71.

A sustainable composite of rice-paper/BaMoO4 nanoparticles for the photocatalytic elimination of the recalcitrant 2,6-dichlorobenzamide (BAM) pesticide in drinking water and its mechanisms of degradation

This research reports the use of biodegradable and flexible composites for the removal of the 2,6-dichlorobenzamide (BAM) pesticide from drinking water. Rice paper (a biodegradable substrate) and Ag/BaMoO4 (MOBA) nanoparticles were employed to fabricate these composites. The SEM images showed that the MOBA nanoparticles with sizes of 300-800 nm decorated the surface of the biodegradable substrate and formed porous agglomerates, which have sizes of 1-3 μm. The MOBA powders were dispersed in drinking water polluted with BAM and were exposed to 4 h of UV-VIS irradiation, producing a maximum degradation of 82% for the BAM. Moreover, the flexible and biodegradable rice/MOBA composite produced a maximum removal percentage of 95% for the BAM. Also, we studied the effect of pH of the initial solution utilizing both powders and composites. From here, we found that a pH of 10 leads to a complete degradation of BAM after 4h, while a pH of 3 degraded only 37-47% of BAM for the same reaction time. According to the scavenger experiments, the •OH radical and the h+ were the main oxidizing agents for the BAM. Overall, the biodegradable photocatalytic composites are a reliable and a low-cost alternative to eliminate pesticides from the drinking water and can find application in water purification processes.

Determination of genotoxic damages of picloram and dicamba with comet assay in Allium cepa rooted in tissue culture and distilled water

BACKGROUND

Many genotoxicity tests allow us to understand the mechanism of damages on genetic material occurring in living organisms against various physical and chemical agents. One of them is the Comet test. The current study aimed to evaluate genotoxic caused by picloram and dicamba to root meristems of Allium cepa utilizing comet assay.

METHODS

Two different protocols were used for rooting and auxin/pesticide application. (i) A. cepa bulbs were rooted in MS medium and then treated with Murashige and Skoog (MS) medium (control) and 0.67, 1.34, 2.01, 2.68, 3.35, 4.02, and 8.04 mg/L of picloram and dicamba using aseptic tissue culture techniques. (ii) A. cepa bulbs were then rooted in bidistilled water and treated with 0 (control), 0.67, 1.34, 2.01, 2.68, 3.35, 4.02, and 8.04 mg/L of picloram and dicamba in distilled water. The A. cepa root tip cells in both treatment groups were examined using comet test to find the possible DNA damaging effects of picloram and dicamba.

RESULTS

The results obtained at all the concentrations were statistically compared with their control groups. Almost at all the concentrations of Picloram and dicamba increased comet tail intensity (%) and tail moment in roots treated in MS medium. Two highest concentrations revealed toxic effect. On the other hand, DNA damaging effect of both auxins was only noted on the highest (> 4.02 mg/L) in roots treated in distilled water.

CONCLUSIONS

This study approve and confirm genotoxic effects of how growth regulators on plants. These findings give an evidence of DNA damage in A. cepa. Therefore, both picloram and dicamba should only be used in appropriate and recommended concentrations in agriculture to conserve ecosystem and to pose minimum threat to life.

Cancer Epidemiology in Hispanic Populations: What Have We Learned and Where Do We Need to Make Progress?

The Hispanic/Latino(x) population (H/L) in the United States of America is heterogeneous and fast growing. Cancer is the number one cause of death among H/Ls, accounting for 21% of deaths. Whereas for the most common cancers, incidence rates are lower in H/Ls compared with non-H/L White (NHW) individuals, H/Ls have a higher incidence of liver, stomach, cervical, penile, and gallbladder cancers. H/L patients tend to be diagnosed at more advanced stages for breast, colorectal, prostate, and lung cancers, and melanoma compared with NHW individuals. Etiologic and cancer outcomes research among H/Ls lags other populations. In this review, we provide a summary of challenges, opportunities, and research priorities related to cancer etiology, cancer outcomes, and survivorship to make progress in addressing scientific gaps. Briefly, we prioritize the need for more research on determinants of obesity, nonalcoholic fatty liver disease and its progression to liver cancer, stomach and gallbladder cancers, and pediatric acute lymphoblastic leukemia. We emphasize the need to improve cancer screening, early detection of cancer, and survivorship care. We highlight critical resources needed to make progress in cancer epidemiologic studies among H/L populations, including the importance of training the next generation of cancer epidemiologists conducting research in H/Ls.

Role of land use and land cover in residential exposures to agricultural pesticide models

Exposure of the general population to pesticides, especially in agricultural areas, is a major public health concern. This review analyses the role of Land Use and Land Cover (LULC) in Residential Exposure to Agricultural Pesticides (REAP) and how it is measured and modelled. Some epidemiological studies have shown that basic LULC variables, such as distance to a crop and field size, are relevant for explaining REAP. However, the potential of LULC mitigation elements, such as vegetation barriers, grassy strips and buffer zones, to mitigate REAP has been poorly studied. The availability of recent low-cost and high-quality geospatial data enables REAP models to include alternative and more precise LULC variables. This review also highlights the need for (i) generic environmental sampling protocols, (ii) exposure and spraying datasets and (iii) assessment of the mitigation capacity of LULC to improve REAP modelling significantly.

Pesticide applicators and cancer: a systematic review

The objective of the study was to identify and analyse the research done on the occurrence of cancer among pesticide applicators by conducting a systematic review of the scientific literature. PRISMA Guidelines was followed to conduct the study. Search was done in Scopus, PubMed, Embase, MEDLINE and Google Scholar databases with search terms "PESTICIDE APPLICATORS", "CANCER" using Boolean operator "AND". Meta-analysis and review articles were excluded from the study. A total of 32 studies were identified among which the average sample size was found to be 60,521. Increased RRs/ORs and positive exposure-response relationships were observed for 31 pesticides. Organophosphate and organochlorine classes of pesticides were the most to be associated with cancer. Lung cancer was observed the most followed by prostate, multiple myeloma and colon cancers among pesticide applicators. It was concluded that there is an increased risk of cancer among the pesticide applicators, whereby which bringing into focus the need to educate and train the workers on following adequate safety measures and making them aware of the hazardous chemicals. Further evaluation on the carcinogenicity of pesticides is also required.

Trifluralin residues in soils from main cotton fields of China and associated ecological risk

Trifluralin is a widely used dinitroaniline herbicide in cotton fields of China but is highly persistent in the environment and can act as a biotoxin and cause genotoxicity to terrestrial organisms, including humans. In this study, the concentrations and distribution of trifluralin residues in 139 soil samples from the major cotton-producing areas of China were investigated. The trifluralin concentrations ranged from ND (not detected) to 66.39 μg/kg dry weight (dw), with a geometric mean of 4.13 μg/kg dw. The detection frequency of trifluralin in Hebei (75%) was higher than that in Xinjiang (66%) and Shandong (40%), but the mean trifluralin concentration was highest in Xinjiang (5.98 μg/kg dw), followed by Hebei (5.06 μg/kg dw) and Shandong (3.19 μg/kg dw). No trifluralin residues were detected in cotton soil in Anhui, Jiangxi and Hunan. The residual amount of trifluralin in soil was significantly correlated with the soil organic matter content. The risk quotient method was used to evaluate the ecological risks associated with trifluralin. Results indicated that trifluralin in all the samples had a low risk to earthworms, but trifluralin in same cotton soils showed high risks to wheat, barley and lucerne. Overall, our work is helpful to understand the residual situation of trifluralin in Chinese cotton soil, to assess the environmental risk of trifluralin, and to control the use and safety of trifluralin in cotton field cultivation.

Excretion of Heavy Metals and Glyphosate in Urine and Hair Before and After Long-Term Fasting in Humans

Background: Dietary exposure to environmental pollutants in humans is an important public health concern. While long-term fasting interrupts the dietary exposure to these substances, fat mobilization as an energy source may also release bioaccumulated substances. This was, to our knowledge, only investigated in obese people decades ago. This study explored the effects of 10-days fasting on the excretion of heavy metals and glyphosate.

Methods: Urinary levels of arsenic, chromium, cobalt, lead, nickel, mercury and glyphosate were measured before and after 10 fasting days in 109 healthy subjects. Additionally, hair analysis was done before and ten weeks after fasting in 22 subjects.

Results: Fasting caused a decrease in body weight, and in urinary arsenic (by 72%) and nickel (by 15%) concentrations. A decrease in lead hair concentrations (by 30%) was documented. Urinary mercury levels were unchanged for chromium, cobalt and glyphosate, which were undetectable in most of the subjects. Additionally, fatigue, sleep disorders, headache and hunger were reduced. Body discomfort symptoms diminished four weeks after food reintroduction.

Conclusions: The results of this study provide the first insights into the changes in heavy metal excretion caused by long-term fasting. Further studies focusing on the kinetics of efflux between different compartments of the body are needed.

Clinical Trial Registration:https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00016657, identifier: DRKS00016657.

Facile synthesis of an aggregation-induced emission (AIE) active imidazoles for sensitive detection of trifluralin

A novel imidazoles fluorescent probe (2) was synthesized from vanillin, o-phenylenediamine, and N,N-diphenylcarbamyl chloride. Its structure was characterized by fluorescence spectra, UV-Vis spectra, ¹H NMR, ¹³C NMR, and high-resolution mass spectrometry (HRMS). Moreover, its aggregation-induced emission (AIE) feature was investigated in THF/MeOH solution. Furthermore, the fluorescence quenching experimental results suggest that compound 2 is the potential fluorescent probe of small organic molecules showing high selectivity and sensitivity for nitroaromatic compounds. In addition, the probe could be applied in the determination of trifluralin with fast response and stability. The fluorescence response of the probe exhibited a good linear correlation with the concentration of trifluralin ranging from 10 to 100 μM, and the limit of detection (LOD) was as low as 5.066 μM. Finally, the probe was successfully utilized to determine the amount of trifluralin in real samples, and the recoveries were 91.1% to 111.2%, indicating the applicability and reliability of the probe.

Association between pesticide exposure and colorectal cancer risk and incidence: A systematic review

BACKGROUND

Studies investigating the association between pesticide exposure and colorectal cancer (CRC) risk have been inconclusive.

OBJECTIVES

Investigate the association between pesticide exposure and CRC risk through a systematic literature review.

METHODS

CRC has the fourth-highest rate of cancer-caused death in the US after lung cancer, breast cancer in women, and prostate cancer in men. Here we have conducted a systematic literature search on studies examining the association between any pesticide exposure and CRC risk using PubMed, MEDLINE via EBSCO host, and Embase according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist.

RESULTS

Following the review, 139 articles were included for qualitative evaluation. Study participants were farmers, pesticide applicators, pesticide manufacturers, spouses of pesticide applicators, farm residents, Korean veterans of the Vietnam War, rural communities, and those who consumed food with pesticide residues. The studies' results were split between those with significant positive (39 significant results) and inverse (41 significant results) associations when comparing pesticide exposure and CRC risk.

DISCUSSION

From our literature review, we have identified a similar number of significant positive and inverse associations of pesticide exposure with CRC risk and therefore cannot conclude whether pesticide exposure has a positive or inverse association with CRC risk overall. However, certain pesticides such as terbufos, dicamba, trifluralin, S-ethyl dipropylthiocarbamate (EPTC), imazethapyr, chlorpyrifos, carbaryl, pendimethalin, and acetochlor are of great concern not only for their associated elevated risk of CRC, but also for the current legal usage in the United States (US). Aldicarb and dieldrin are of moderate concern for the positive associations with CRC risk, and also for the illegal usage or the detection on imported food products even though they have been banned in the US. Pesticides can linger in the soil, water, and air for weeks to years and, therefore, can lead to exposure to farmers, manufacturing workers, and those living in rural communities near these farms and factories. Approximately 60 million people in the US live in rural areas and all of the CRC mortality hotspots are within the rural communities. The CRC mortality rate is still increasing in the rural regions despite the overall decreasing of incidence and mortality of CRC elsewhere. Therefore, the results from this study on the relationship between pesticide exposure and CRC risk will help us to understand CRC health disparities.

Interaction of Human Alpha-2-Macroglobulin with Pesticide Aldicarb Using Spectroscopy and Molecular Docking

BACKGROUND

Aldicarb is a carbamate pesticide commercially used in potato crop production. Once it enters human body, it interacts with diverse proteins and other substances.

OBJECTIVE

Aldicarb is toxic to human health and it is also a cholinesterase inhibitor, which prevents the breakdown of acetylcholine in synapse. Human alpha-2-macroglobulin (α2M), is a large tetrameric glycoprotein of 720 kDa with antiproteinase activity, found abundantly in plasma.

METHODS

In the present study, the interaction of aldicarb with alpha-2-macroglobulin was explored utilizing various spectroscopic techniques and molecular docking studies.

RESULTS

UV-vis and fluorescence spectroscopy suggests the formation of a complex between aldicarb and α2M apparent by increased absorbance and decreased fluorescence with static quenching mode. CD spectroscopy indicates a slight change in the structure of alpha-2-macroglobulin. Docking studies confirm the interaction of aldicarb with Pro- 1391, Leu-1392, Lys-1393, Val-1396, Lys- 1397, Thr-1408, Glu-1409, Val-1410, Asp-282 and Glu-281 in the receptor binding domain at the C-terminal of the alpha 2 macroglobulin.

DISCUSSION

In this work, aldicarb is shown to bind with alpha 2-macroglobulin at receptor binding domain which is the binding site for various extracellular and intracellular ligand too. Also, affecting the functional activity of the protein may lead to further physiological consequences.

CONCLUSION

It is possible that aldicarb binds and compromises antiproteinase activity of α2M and binding properties by inducing changes in the secondary structure of the protein.

Transformation of fluopyram during enzymatic hydrolysis of apple and its effect on polygalacturonase and apple juice yield

China is one of the largest apple-growing areas in the world. Fluopyram (FLP) is a novel pesticide that has been widely used in agriculture. This work investigated the behavior of pesticides during enzymatic hydrolysis of apple juice and its effect on polygalacturonase (PG), apple juice yield, and flavor. The study findings revealed that 27.5% to 34.2% FLP was degraded during the enzymatic hydrolysis of apple. The three degradation products (P1, P2, and P3) were identified by a hybrid ion trap-orbitrap mass spectrometer. Based on toxicity assessment, it was found that carcinogenicity was higher for P2 and P3 than for FLP. Furthermore, FLP affected the yield and flavor of apple juice. FLP reduced yield by 4.8%, because FLP inhibited the activity of PG. Through molecular docking, it was found that there was an interaction between the active center of PG and FLP, resulting in a reduction in catalytic ability.

Pyrethroid based pesticides - chemical and biological aspects

Human and animal welfare primarily depends on the availability of food and surrounding environment. Over a century and half, the quest to identify agents that can enhance food production and protection from vector borne diseases resulted in the identification and use of a variety of pesticides, of which the pyrethroid based ones emerged as the best choice. Pesticides while improved the quality of life, on the other hand caused enormous health risks. Because of their percolation into drinking water and food chain and usage in domestic settings, humans unintentionally get exposed to the pesticides on a daily basis. The health hazards of almost all known pesticides at a variety of doses and exposure times are reported. This review provides a comprehensive summation on the historical, epidemiological, chemical and biological (physiological, biochemical and molecular) aspects of pyrethroid based insecticides. An overview of the available knowledge suggests that the synthetic pyrethroids vary in their chemical and toxic nature and pose health hazards that range from simple nausea to cancers. Despite large number of reports, studies that focused on identifying the health hazards using doses that are equivalent or relevant to human exposure are lacking. It is high time such studies are conducted to provide concrete evidence on the hazards of consuming pesticide contaminated food. Policy decisions to decrease the residual levels of pesticides in agricultural products and also to encourage organic farming is suggested.

In Vitro Antioxidant Activity of Litsea martabanica Root Extract and Its Hepatoprotective Effect on Chlorpyrifos-Induced Toxicity in Rats

In Thailand, people in the highland communities whose occupational exposure to pesticides used the root of Litsea martabanica as a detoxifying agent. However, the scientific data to support the traditional use of this plant are insufficient. This study aimed to evaluate the antioxidant activity and anti-pesticide potential of L. martabanica root extract. Antioxidant properties were investigated by 2,2′-diphenyl-1-picrylhydrazyl (DPPH) assay, superoxide radicals scavenging assay, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay, ferric reducing antioxidant power (FRAP), and total phenolic content determination. In all assays, L. martabanica extracts and their fractions exhibited high antioxidant activities differently. The water extract is traditionally used as a detoxifying agent. Therefore, it was chosen for in vivo experiments. The rats received the extract in a way that mimics the traditional methods of tribal communities followed by chlorpyrifos for 16 days. The results showed that acetylcholinesterase activity decreases in pesticide-exposed rats. Treatment with the extract caused increasing acetylcholinesterase activity in the rats. Therefore, L. martabanica extract may potentially be used as a detoxifying agent, especially for the chlorpyrifos pesticide. The antioxidant properties of L. martabanica may provide a beneficial effect by protecting liver cells from damage caused by free radicals. Histopathology results revealed no liver cell necrosis and showed the regeneration of liver cells in the treatment group. L. martabanica extract did not cause changes in behavior, liver weight, hematological and biochemical profiles of the rats.

Responses to environmental variability by herbivorous insects and their natural enemies within a bioenergy crop, Miscanthus x giganteus

Precision agriculture (PA) is the application of management decisions based on identifying, quantifying, and responding to space-time variability. However, knowledge of crop pest responses to within-field environmental variability, and the spatial distribution of their natural enemies, is limited. Quantitative methods providing insights on how pest-predator relationships vary within fields are potentially important tools. In this study, phloem feeders and their natural enemies, were observed over two years across 81 locations within a field of the perennial feedstock grass in Georgia, USA. Geographically weighted regression (GWR) was used to spatially correlate their abundance with environmental factors. Variables included distance to forest edge, Normalized Difference of Vegetation Index (NDVI), slope, aspect, elevation, soil particle size distribution, and weather values. GWR methods were compared with generalized linear regression methods that do not account for spatial information. Non-spatial models indicated positive relationships between phloem-feeder abundance and wind speed, but negative relationships between elevation, proportions of silt and sand, and NDVI. With data partitioned into three seasonal groups, terrain and soil variables remained significant, and natural enemies and spiders became relevant. Results from GWR indicated that magnitudes and directions of responses varied within the field, and that relationships differed among seasons. Strong negative relationships between response and explanatory factors occurred: with NDVI during mid-season; with percent silt, during mid-, and late seasons; and with spider abundance during early and late seasons. In GWR models, slope, elevation, and aspect were mostly positive indicating further that associations with elevation depended on whether models incorporated spatial information or not. By using spatially explicit models, the analysis provided a complex, nuanced understanding of within-field relationships between phloem feeders and environmental covariates. This approach provides an opportunity to learn about the variability within agricultural fields and, with further analysis, has potential to inform and improve PA and habitat management decisions.

Bixafen, a succinate dehydrogenase inhibitor fungicide, causes microcephaly and motor neuron axon defects during development

Succinate dehydrogenase inhibitors (SDHIs), the most widely used fungicides in agriculture today, act by blocking succinate dehydrogenase (SDH), an essential and evolutionarily conserved component of mitochondrial respiratory chain. Recent results showed that several SDHIs used as fungicides not only inhibit the SDH activity of target fungi but also block this activity in human cells in in vitro models, revealing a lack of specificity and thus a possible health risk for exposed organisms, including humans. Despite the frequent detection of SDHIs in the environment and on harvested products and their increasing use in modern agriculture, their potential toxic effects in vivo, especially on neurodevelopment, are still under-evaluated. Here we assessed the neurotoxicity of bixafen, one of the latest-generation SDHIs, which had never been tested during neurodevelopment. For this purpose, we used a well-known vertebrate model for toxicity testing, namely zebrafish transparent embryos, and live imaging using transgenic lines labelling the brain and spinal cord. Here we show that bixafen causes microcephaly and defects on motor neuron axon outgrowth and their branching during development. Our findings show that the central nervous system is highly sensitive to bixafen, thus demonstrating in vivo that bixafen is neurotoxic in vertebrates and causes neurodevelopmental defects. This work adds to our knowledge of the toxic effect of SDHIs on neurodevelopment and may help us take appropriate precautions to ensure protection against the neurotoxicity of these substances.

Uso de agrotóxicos e mortalidade por câncer em regiões de monoculturas

RESUMO O uso de agrotóxicos na agricultura brasileira é um problema de saúde pública, dadas as contaminações no ambiente, em alimentos e as intoxicações resultantes do uso dessas substâncias. O objetivo deste artigo é investigar a distribuição espacial das áreas plantadas de lavouras e as taxas de mortalidade de alguns tipos de câncer: mama, colo do útero e próstata. Escolheram-se quatro estados brasileiros que possuem grande produção de commodities agrícolas a serem estudadas. Trata-se de um estudo ecológico de análise espacial conduzido com dados e informações do Sistema de Informação sobre Mortalidade (SIM) do Ministério da Saúde, por meio do qual elaboraram-se taxas de mortalidade para os referidos tipos de câncer, cujos óbitos tenham ocorrido entre 1996 e 2016. Há indícios de que existe correspondência entre as áreas de maior estimativa de uso de agrotóxicos Disruptores Endócrinos e o aumento das taxas de mortalidade pelos diferentes tipos de câncer.

Exposure to organophosphorus insecticides and increased risks of health and cancer in US women

Results of this paper provide evidence that chronic long-term exposure to organophosphorus insecticides poses a significantly higher health risk for US women than for men, based on dialkylphosphate biomarker data from NHANES cycles 2003-2012. The risk of cardiovascular disease for female non-smokers aged 60-85 years in the highest dimethylthiophosphate (DMTP) urinary concentration quartile is 3.0 (odds ratio, OD = 3.0, 95%CI 1.4-6.4) times higher than that in the lowest quartile. Women with higher urinary DMTP concentrations also have significantly higher risk of asthma at the ages 6-39 years and an apparently higher risk of chronic bronchitis at the ages 60-85. Overall cancer risk is significantly higher for female non-smokers aged 60-85 years in the higher urinary DMTP quartiles (OD = 2.7, 95% CI 1.3-5.9). Increasing risks of breast cancer for female smokers and prostate cancer for male smokers aged 60-85 years with higher exposure to organophosphorus insecticides in the US are also significant.

Biodegradation and Abiotic Degradation of Trifluralin: A Commonly Used Herbicide with a Poorly Understood Environmental Fate

Trifluralin is a widely used dinitroaniline herbicide, which can persist in the environment and has substantial ecotoxicity, especially to aquatic organisms. Trifluralin is very insoluble in water (0.22 mg/L at 20 °C) and highly volatile (vapor pressure of 6.7 mPa at 20 °C); these physicochemical properties determine a large part of its environmental fate, which includes rapid loss from soils if surface-applied, strong binding to soil organic matter, and negligible leaching into water. The trifluralin structure contains a tertiary amino group, two nitro-groups and a trifluoromethyl- group. Despite the strongly xenobiotic character of some of these substituents, biodegradation of trifluralin does occur, and pure cultures of bacteria and fungi capable of partially degrading the molecule either by dealkylation or nitro-group reduction have been identified. There are many unanswered questions about the environmental fate and metabolism of this herbicide; the genes and enzymes responsible for biodegradation are largely unknown, the relative roles of abiotic processes vs growth-linked biodegradation vs cometabolism are unresolved, and the impact of different environmental factors on the rates and extents of biodegradation are not clear. Here, we summarize the relevant literature on the persistence and environmental fate of trifluralin with a focus on biodegradation pathways and mechanisms, and we identify the current major knowledge gaps for future research.

Chlorpyrifos-induced cell proliferation in human breast cancer cell lines differentially mediated by estrogen and aryl hydrocarbon receptors and KIAA1363 enzyme after 24 h and 14 days exposure

Organophosphate biocide chlorpyrifos (CPF) is involved with breast cancer. However, the mechanisms remain unknown. CPF increases cell division in MCF-7 cells, by estrogen receptor alpha (ERα) activation, although it is a weak ERα agonist, suggesting other mechanisms should be involved. Aromatic hydrocarbon receptor (AhR) activation increases cell division in human breast cancer cells, and CPF strongly activates it. Finally, the KIAA1363 enzyme, which is regulated by CPF, is overexpressed in cancer cells. Accordingly, we hypothesized that CPF or its metabolite chlorpyrifos-oxon (CPFO) could induce cell viability promotion in MCF-7 and MDA-MB-231 cell lines, through mechanisms related to ERα, AhR, and KIAA1363, after 24 h and 14 days treatment. Results show that, after acute and long-term treatment, CPF and CPFO alter differently KIAA1363, AhR, ER and cytochrome P450 isoenzyme 1A1 (CYP1A1) expression. In addition, they induced cell proliferation through ERα activation after 24 h exposure in MCF-7 cells and through KIAA1363 overexpression and AhR activation in MCF-7 and MDA-MB-231 cells after acute and long-term treatment. The results obtained in this work provide new information relative to the mechanisms involved in the CPF toxic effects that could lead to breast cancer disease.

Toxicity of the herbicides used on herbicide-tolerant crops, and societal consequences of their use in France

In France, the implementation of mutant herbicide-tolerant crops and the use of the related herbicides - sulfonylureas and imidazolinones - have triggered a strong societal reaction illustrated by the intervening actions of environmentalist groups illegally mowing such crops. Trials are in progress, and therefore should be addressed the questions of the environmental risks and the toxicity of these herbicides for the animals and humans consuming the products derived from these plants. Regulatory authorities have allowed these mutant and herbicide-tolerant plants arguing that the herbicides against which they resist only target an enzyme found in 'weeds' (the acetolactate synthase, ALS), and that therefore all organisms lacking this enzyme would be endowed with immunity to these herbicides. The toxicological literature does not match with this argument: 1) Even in organisms displaying the enzyme ALS, these herbicides impact other molecular targets than ALS; 2) These herbicides are toxic for animals, organisms that do not possess the enzyme ALS, and especially invertebrates, amphibians and fish. In humans, epidemiological studies have shown that the use and handling of these toxins are associated with a significantly increased risk of colon and bladder cancers, and miscarriages. In agricultural soils, these herbicides have a persistence of up to several months, and water samples have concentrations of some of these herbicides above the limit value in drinking water.

Production of a specific monoclonal antibody for 1-naphthol based on novel hapten strategy and development of an easy-to-use ELISA in urine samples

1-naphthol (1-NAP) is the main metabolite of pesticide carbaryl and naphthalene, and is also a genotoxic and carcinogenic intermediate in the synthesis of organic compound, dyes, pigment and pharmaceutical industry. In this work, two novel haptens were designed and synthesized for developing a competitive indirect enzyme-linked immunosorbent assay (ciELISA) method for 1-NAP in urine samples. The assay showed a limit of detection of 2.21 ng/mL and working range from 4.02 ng/mL to 31.25 ng/mL for 1-NAP in optimized working buffer. The matrix effect of samples was eliminated via 15-fold dilution of optimized working buffer. Good average recoveries (102.4%-123.4%) with a coefficient of variation from 11.7% to 14.7% was obtained for spiked urine samples. Subsequent instrument verification test showed good correlation between the results of ciELISA and high-performance liquid chromatography. The developed ciELISA is a high-throughput tool to monitor 1-NAP in urine, which can provide technical support for the establishment of biological exposure level for the exposure to carbaryl, naphthalene and other related pollutants.

Determination of glyphosate and glufosinate in corn using multi-walled carbon nanotubes followed by ultra high performance liquid chromatography coupled with tandem mass spectrometry

Glyphosate (Glyp) and glufosinate (Gluf) are widely used herbicides around the world, and their effects on human health and detection of levels have drawn increasing attention. The present study was to establish a method to determine the contents of Glyp and Gluf from corn using multi-walled carbon nanotubes (MWCNTs) followed by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The corn samples were purified by MWCNTs, then the analytes reacted with 9-fluorenylmethylchloroformate (FMOCCl) of acetonitrile solution (20.0 g/L) at 50 °C water bath in a borate buffer solution (50.0 g/L, pH=9) to generate FMOC derivative products. After the derivatization, HSS T3 was used as the separation column, with acetonitrile and 0.05% ammonia as the mobile phase, and multiple reaction monitoring (MRM) mode with negative electrospray ionization (ESI-) was adopted. The validation parameters showed good verification results, with both of their quantitative limits (LOQ) as 0.005 mg/kg, recoveries between 90.3% and 95.4%, intra-day relative standard deviations (RSDs) in the ranges of 1.24% and 3.35%, and inter-day RSDs between 3.56% and 6.06%. The analytical method, developed in this study, has high accuracy and sensitivity, and is suitable for the simultaneous detection of Glyp and Gluf in corn.

Organochlorine pesticides induce inflammation, ROS production, and DNA damage in human epithelial ovary cells: An in vitro study

Although the etiology of ovarian cancer is not clear, certain factors are implicated in this disease, such as ovulation, gonadotropic and steroid hormones, growth factors, cytokines, environmental agents, etc. Epidemiological studies have proven environmental exposure to pesticides with an increased risk of Epithelial Ovarian Cancer (EOC); however, the molecular mechanism underlying the carcinogenic effects of pesticides in human ovary remains poorly understood. The present study aimed to study the pro-inflammatory response of organochlorine pesticides (OCPs) namely β-hexachlorocyclohexane (β-HCH), dichlorodiphenyldichloroethylene (DDE) and Dieldrin following exposure to human ovary surface epithelial cells (HOSE) for risk prediction of epithelial ovarian cancer. We found high level of Reactive oxygen species (ROS) production and DNA damage along with up-regulation of pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, nuclear factor kappa B (NF-kB) and cyclooxygenase (COX)-2 expression in OCPs treated HOSE cells compared to control (DMSO). The result of the present study suggests that β-HCH, DDE, and Dieldrin exposure induce ROS and pro-inflammatory response as well as DNA damage in HOSE cells. These various results show that OCPs may account for the neoplastic transformation of HOSE cells in the ovary.

Organophosphate insecticide exposure and telomere length in U.S. adults

BACKGROUND

Organophosphate insecticides have been widely used for >30 years, and are reported to be associated with various age-related chronic diseases. While shortening of telomere length has been considered as a marker of cellular aging, only a few small studies have been conducted to examine any difference of telomere length in workers exposed to organophosphates versus controls. Epidemiologic studies of the dose-response associations between environmental organophosphate exposure and telomere length in the general population are few.

OBJECTIVE

This study aimed to evaluate the association between levels of organophosphate insecticide exposure and telomere length in the general population.

METHODS

We analyzed data for 1724 participants aged 20 years or more from the National Health and Nutrition Examination Survey 1999-2002. Organophosphate insecticide exposure was estimated using measures of urinary concentrations for 3,5,6-trichloro-2-pyridinol (TCPY) and six non-specific dialkyl phosphate metabolites, e.g., diethyl thiophosphate (DETP). Multiple linear regression was conducted to assess the association between organophosphate exposure and telomere length.

RESULTS

After controlling for sociodemographic and physical factors and urinary creatinine, participants in the second quartile for urinary TCPY had 0.06 (95% CI: 0.02-0.10) T/S ratio shorter telomere length than those in the lowest quartile. By contrast, participants in the second and third tertiles of urinary DETP had 0.08 (95% CI: 0.02-0.14) and 0.06 (95% CI, 0.01-0.11) T/S ratio longer telomere length than those in the lowest tertile. For other five metabolites, there was no association with telomere length.

CONCLUSIONS

Levels of environmental exposures to certain organophosphate insecticides may be linked to altered telomere length in adults in the general population. Although our findings may need to be replicated, we provide the first evidence that environmental exposure to organophosphates may contribute to the alteration of telomere length, which is potentially related to biological aging and to the development of various chronic diseases.

Do trifluralin and tebuthiuron impair isolated rat liver mitochondria?

Emerging contaminants, such as the herbicides trifluralin and tebuthiuron, comprise a class of compounds for which toxicological data are lacking, especially data regarding their harmful effects and biomarkers of exposure. Their potential damage to the environment and non-target organisms makes understanding their toxic mechanisms an urgent matter. Mitochondria, which exert an energy production function, play a vital role in maintaining many cellular activities and therefore are reliable predictors of substance toxicity. This study evaluates whether the herbicides trifluralin and tebuthiuron (at concentrations ranging from 1 to 100 μM) affect isolated rat liver mitochondria. The herbicides were analyzed according to their ability to interact with the mitochondrial membrane and induce swelling, lipoperoxidation, ROS formation, and NAD(P)H oxidation; dissipate the membrane potential; dysregulate calcium homeostasis; and alter ATP and GSH/GSSG levels. Tebuthiuron does not disrupt the mitochondrial biochemistry at any of the tested concentrations. In contrast, trifluralin can disturb the mitochondrial respiration, especially at the highest concentration, but it cannot induce oxidative stress. These results suggest that the aforementioned effects can occur as toxic mechanisms of trifluralin in non-target organisms, as well.

Pesticide exposure and cancer: an integrative literature review

ABSTRACT We conducted an integrative literature review of published studies on pesticide and cancer exposure, focusing on farmers, rural population, pesticide applicators, and rural workers. The Medline/PubMed was used as searching database. After the retrieval, 74 articles were selected according to pre-established criteria, which design involved 39 case-controls, 32 cohorts, 2 ecological ones, and 1 cross-sectional. Among them, 64 studies showed associations between pesticides and cancer while 10 did not find any significant association. The studies found 53 different types of pesticides significantly associated with at least one type of cancer and 19 different types of cancers linked to at least one type of pesticide. Although few studies presented contradictory results, the sole fact of being a farmer or living near crops or high agricultural areas have also been used as a proxy for pesticide exposure and significantly associated with higher cancer risk. The literature well illustrates the case of prostate cancer, Non-Hodgkin lymphoma, leukemia, multiple myeloma, bladder and colon cancers. Studies are recommended to further investigate the relationship between pesticide and neoplasm of testis, breast, esophagus, kidney, thyroid, lip, head and neck, and bone.

Telomere length in workers was effected by omethoate exposure and interaction between smoking and p21 polymorphisms

Omethoate is an organophosphorus pesticide that poses a major health hazard, especially DNA damage. The purpose of this study was to investigate the factors affecting telomere length in workers exposed to omethoate by analyzing the interaction between cell cycle gene polymorphism and environmental factors. The exposure group consisted of 118 workers exposed to omethoate for 8-10 years, the control group comprised 115 healthy people without occupational toxicant exposure history. The telomere length of genomic DNA from peripheral blood leucocyte was determined with real-time PCR. Polymerase chain reaction and restriction fragment length polymorphism was used to detect the polymorphisms in p53, p21 and MDM2 gene. The telomere length in the (CA + AA) genotypes for p21 rs1801270 polymorphism was longer than that in the CC genotype in control group (P = 0.015). The generalized linear model analysis indicated the interaction of the p21 rs1801270 polymorphic (CA + AA) genotypes and smoking has a significant effect on telomere length (β = -0.258, P = 0.085). The prolongation of telomere length in omethoate-exposed workers was associated with genotypes (CA + AA) of p21 rs1801270, and interactions of (CA + AA) genotypes and smoking factor.

Pyrethroid pesticide exposure and hematological cancer: epidemiological, biological and molecular evidence

Pyrethroid insecticides are commonly used worldwide. The chronic effects of these compounds are of concern given that epidemiological studies have suggested an association with hematological cancer, particularly in children. However, the biological evidence at molecular and cellular levels is limited. A review on the molecular and cellular effects of pyrethroids is helpful to guide the study of the biological plausibility of the association of pyrethroids with hematological cancer. We reviewed studies suggesting that pyrethroids are genotoxic, induce genetic rearrangements, alter gene expression and modify DNA. All of these biological modifications could potentially contribute to the carcinogenic process in hematopoietic cells.

Toxicity of 10 organic micropollutants and their mixture: Implications for aquatic risk assessment

Micropollutants, as a serious water pollution issue, raise considerable toxicological concerns, particularly when present as components of complex mixtures. Due to the interactions of environmental pollution components (contaminant), the micropollutant problem is increasingly complex, thus, water quality of organic chemical contamination assessed substance-by-substance might lead to underestimation in aquatic environmental risk assessment. To assess the aquatic environmental risk of micropollutants mixture, a total of 10 organic micropollutants were selected and analysed by an approach of integration of literature data, laboratory experiments and prediction techniques. The experiment results showed that all 10 micropollutants were capable of causing toxicity in zebrafish embryos, aquatic invertebrates and algae with the LC50 (50% lethal concentration) values from 1.14 mg/L to 14.37 mg/L. Triclosan, carbamazepine, diazinon and diuron were the most hazardous compounds in the Danube River and the Rhine River. The artificial mixture presented a strong antagonistic relationship, which demonstrated an independent action (IA) model of the mixture. Based on the observed toxicity data, the risk quotients (RQs) of environmental mixtures of the Danube River and the Rhine River were extrapolated. It can be concluded that the micropollutant mixture may pose a potential risk for aquatic ecosystems with the present environmentally measured concentrations in the Danube River and Rhine River. Mixture risk assessment results suggested that the toxicity of studied chemicals might be induced by dissimilar actions, which is in agreement with the mixture toxicity prediction of the IA model. The observed findings could be useful to establish an overview of the pressures, vision, measures and expectations for hazardous substances pollution, which can help in making to informed decisions to reduce the concentration and bioactive fraction of pollutants.

Role of Emerging Environmental Risk Factors in Thyroid Cancer: A Brief Review

Environmental factors are recognized as risk factors of thyroid cancer in humans. Exposure to radiation, both from nuclear weapon or fallout or medical radiation, and to some organic and inorganic chemical toxicants represent a worldwide public health issue for their proven carcinogenicity. Halogenated compounds, such as organochlorines and pesticides, are able to disrupt thyroid function. Polychlorinated biphenyls and their metabolites and polybrominated diethyl ethers bind to thyroid, transport proteins, replace thyroxin, and disrupt thyroid function as phthalates and bisphenolates do, highly mimicking thyroid hormones. A better knowledge of environmental risks represents a very important tool for cancer prevention through true risks prevention and management. This approach is very important because of the epigenetic origin’s theory of cancer. Therefore, the aim of this review was study the association between environmental agents and thyroid cancer promotion.

High highs and low lows: Elucidating striking seasonal variability in pesticide use and its environmental implications

Despite substantial public and scientific concern regarding unintended environmental and health consequences of agricultural pesticide use, identifying when and where high levels of use occur is stymied by a dearth of data at biologically relevant spatial or temporal scales. Here we investigate intra-annual patterns in pesticide use by crop and by pesticide type using unique pesticide use data from agriculturally diverse croplands of California, USA. We find that timing and type of pesticide use is strongly crop-dependent, and that for many high pesticide use crops, monthly application rates are highly consistent from year-to-year. Further, while pesticide use hotspots are concentrated in early summer, regions with very high use occur throughout the year with spatial distributions varying therein. The enormity of intra-annual variation in pesticide use, as well as the consistency in those patterns through time, suggests opportunities for crop-specific pest management and region-specific mitigation approaches to limit environmental and human health hazards from agricultural pesticide use.

Integrating bioassays, chemical analysis and in silico techniques to identify genotoxicants in surface water

Identification of hazardous compounds, as the first step of water protection and regulation, is still challenged by the difficulty to establish a linkage between toxic effects and suspected contaminants. Genotoxic compounds are one type of highly relevant toxicants in surface water, which may attack the DNA and lead to cancer in individual organism, or even damaged germ cells to be passed on to future generations. Thus, the establishment of a linkage between genotoxic effects and genotoxicant is important for environmental toxicologists and chemists. For this purpose, in the present study in silico methods were integrated with bioassays, chemical analysis and literature information to identify genotoxicants in surface water. Large volume water samples from 22 sampling sites of the Danube were collected and subjected to biological and chemical analysis. Samples from the most toxic sites (JDS32, JDS44 and JDS63) induced significant genotoxic effects in the micronucleus assay, and two of them caused mutagenicity in the Ames fluctuation assay. Chemical analysis showed that 68 chemicals were detected in these most toxic samples. Literature findings and in silico techniques using the OECD QSAR Toolbox and the ChemProp software package revealed genotoxic potentials for 29 compounds out of 68 targeted chemicals. To confirm the integrative technical data, the micronucleus assay and the Ames fluctuation assay were applied with artificial mixtures of those compounds and the raw water sample extracts. The results showed that 18 chemicals explained 48.5% of the genotoxicity in the micronucleus assay. This study highlights the capability of in silico techniques in linking adverse biological effect to suspicious hazardous compounds for the identification of toxicity drivers, and demonstrates the genotoxic potential of pollutants in the Danube.

Pesticide and Human Health

Pesticides are known to be one of the extremely useful and incredibly beneficial agents for preventing losses of crops as well as diseases in humans. They are used in a large number of conditions as in farms, orchards, gardens, parks, sports lawn, residences, industrial areas, shops, schools, hospitals, airports, railway lines, drains, on animals, and on people for control of diseases such as scabies and head lice. People are exposed to pesticides in their daily lives through multiple routes of exposure such as occupational or food, water, and air. Many pesticides can be used safely and effectively, but care must be taken while using them. Several pesticides are beneficial in agriculture for killing pests. Yet many times their injurious effects offset the positive ones. Uses of pesticides are apprehension for sustainability of environment and global stability. This chapter aims to discuss pesticides, their types, routes of their exposure, human health concerns related to them, methods to stop using them, and a future scenario of the world after eradicating pesticides.

Carcinogenic Pesticide Control via Hijacking Endosymbiosis; The Paradigm of DSB-A from Wolbachia pipientis for the Management of Otiorhynchus singularis

BACKGROUND/AIM

Pesticides have little, if any specificity, to the pathogen they target in most cases. Wide spectrum toxic chemicals are being used to remove pestcides and salvage crops and economies linked to agriculture. The burden on the environment, public health and economy is huge. Traditional pestcide control is based on administering heavy loads of highly toxic compounds and elements that essentially strip all life from the field. Those chemicals are a leading cause of increased cancer related deaths in countryside. Herein, the Trojan horse of endosymbiosis was used, in an effort to control pests using high specificity compounds in reduced quantities.

MATERIALS AND METHODS

Our pipeline has been applied on the case of Otiorhynchus singularis, which is a very widespread pest, whose impact is devastating on a repertoire of crops. To date, there is no specific pesticide nor agent to control it. The deployed strategy involves the inhibition of the key DSB-A enzyme of its endosymbiotic Wolbachia pipientis bacterial strain.

RESULTS

Our methodology, provides the means to design, test and identify highly specific pestcide control substances that minimize the impact of toxic chemicals on health, economy and the environment.

CONCLUSION

All in all, in this study a radical computer-based pipeline is proposed that could be adopted under many other similar scenarios and pave the way for precision agriculture via optimized pest control.

Removal of alachlor, diuron and isoproturon in water in a falling film dielectric barrier discharge (DBD) reactor combined with adsorption on activated carbon textile: Reaction mechanisms and oxidation by-products

A falling film dielectric barrier discharge (DBD) plasma reactor combined with adsorption on activated carbon textile material was optimized to minimize the formation of hazardous oxidation by-products from the treatment of persistent pesticides (alachlor, diuron and isoproturon) in water. The formation of by-products and the reaction mechanism was investigated by HPLC-TOF-MS. The maximum concentration of each by-product was at least two orders of magnitude below the initial pesticide concentration, during the first 10 min of treatment. After 30 min of treatment, the individual by-product concentrations had decreased to values of at least three orders of magnitude below the initial pesticide concentration. The proposed oxidation pathways revealed five main oxidation steps: dechlorination, dealkylation, hydroxylation, addition of a double-bonded oxygen and nitrification. The latter is one of the main oxidation mechanisms of diuron and isoproturon for air plasma treatment. To our knowledge, this is the first time that the formation of nitrificated intermediates is reported for the plasma treatment of non-phenolic compounds.

Endosulfan causes the alterations of DNA damage response through ATM-p53 signaling pathway in human leukemia cells

Exposure to pesticides results in DNA damage and genomic instability. We previously predicted that endosulfan might be associated with leukemia, but the role of endosulfan in leukemia cells has been unexplored. The aim of this study is to elucidate molecular mechanism of endosulfan-induced DNA damage response in human leukemia cells. We performed endosulfan exposure experiments in K562 cells with varying concentrations of endosulfan for 48 h and found that endosulfan lowered cell viability in a dose-dependent manner. We observed the dramatic DNA damage using comet assay and the increase of micronucleus in 75 μM endosulfan-exposed cells. Endosulfan at 75 μM caused the expression alterations of ATM and DNA repair genes such as FANCD2, and BRCA1/2 at different exposure time points (12, 24, 48 h), which was reversed by ATM inhibitor KU-55933. Endosulfan significantly increased the mRNA expression levels of p53 and GADD45A, and decreased PCNA and XRCC2 at 48 h after exposure. Flow cytometric analysis showed that endosulfan at 50 and 75 μM induced cell cycle G1 arrest, a response attributed to down-regulation of CDK6 and up-regulation of p21. We also observed that endosulfan at 50 and 75 μM induced a considerable percentage of cells to undergo apoptosis, as detected by Annexin-V binding assays. Endosulfan resulted in the activation of caspase-3, and elevated the expression levels of PUMA and the ratio of BAX/Bcl-2. These findings suggest that endosulfan caused DNA damage response throughATM-p53 signaling pathway, implicating the potential correlation between endosulfan and leukemia.