Household exposure to pesticides and risk of leukemia in children and adolescents: Updated systematic review and meta-analysis

The Growing Burden of Cancer in Adolescent and Young Adults in Asia: A Call to Action

Recent estimates suggest that the lower middle income countries in Asia carry the heaviest burden of cancer among adolescents and young adults (AYAs) (defined as age 15-39 years). A larger proportion of the population in Asia is aged 15-39 compared with the developed countries. This age group is different from the pediatric or the adult group in terms of physical, social, psychological, and financial needs. Cancer incidence, disability, survivorship needs, financial toxicity, psychosocial issues, and so on are underestimated in this group, and available literature is scarce. Global data show an increasing trend of adult-onset cancers such as colorectal, breast, pancreas, and lung in the AYA population. Data suggest that the disease biology and prognosis are different in this group; however, further research is needed. An ESMO/SIOPE/SIOP Asia survey on the care of AYA cancer patients in Asia found a suboptimal availability of AYA specialized centers in the region and identified several unmet needs including lack of training, clinical trials, and high rates of treatment abandonment. There is an urgent need for cancer care systems in Asia to develop specialized services to be able to cater to this growing burden. Training and research in this area also need to be upscaled with the goal of establishing a sustainable infrastructure and quality services to ensure that this vulnerable group receives appropriate care. Management guidelines and national health policies should consider giving special attention to this group as the World Health Assembly reinforces the inclusion of children and adolescents in cancer control programs.

Childhood acute lymphoblastic leukemia survival and spatial analysis of socio-environmental risks in Mexico

Background

Acute lymphoblastic leukemia (ALL) etiology remains largely unknown; incidence patterns by age, sex, and geographical distribution suggest a potential environmental role.

Aim

To identify ALL clusters from four contrasting urban areas of Mexico and to characterize the sources of environmental carcinogens.

Methods

Hospital-based ALL cases (n = 443) diagnosed in children <19 years old from the Metropolitan Zones of Merida and San Luis Potosi, the State of Mexico, and Tijuana were analyzed (2015-2020). ALL cases were coded according to the International Classification of Diseases for Oncology. ALL clusters were identified by Kernel Density, and excess risk was estimated. Data of particulate matter ≤2.5 µm (PM2.5) concentrations measured by community-monitoring stations were analyzed. Geocoded datasets of benzene, polycyclic aromatic hydrocarbons, and PM2.5 sources were analyzed to characterize patterns of exposure in ALL clusters.

Results

The survival rate for ALL ranged from 61.5% to 78.6%. Seven ALL clusters with excess risk (RR 1.4-2.3, p < 0.05) were identified. The carcinogen sources included artisanal brick kilns, gas stations, cement works, carpentry, paint, and chemical manufacturing establishments. PM2.5 levels ranged from 15 µg/m3 to 37 µg/m3 among study areas.

Conclusion

ALL clusters were identified at the community level; the excess risk could be explained by small-scale carcinogen sources. The levels of PM2.5 in outdoor air ranged from 3 to 6 times above the World Health Organization (WHO) air quality guidelines. Healthcare providers must raise awareness of the increased risk of ALL in children living near sources of environmental carcinogens; cancer control and prevention strategies must be steered from a multi-sectoral and multi-action perspective to protect children's health.

Association between Residential Proximity to Viticultural Areas and Childhood Acute Leukemia Risk in Mainland France: GEOCAP Case-Control Study, 2006-2013

BACKGROUND

Pesticide exposures are suspected of being a risk factor for several childhood cancers, particularly acute leukemia (AL). Most of the evidence is based on self-reported parental domestic use of pesticides, but some studies have also addressed associations with agricultural use of pesticides near the place of residence.

OBJECTIVES

The objective of the study was to evaluate the risk of AL in children living close to vines, a crop subject to intensive pesticide use.

METHODS

Data were drawn from the national registry-based GEOCAP study. We included all of the AL cases under the age of 15 years diagnosed in 2006-2013 (n = 3,711 ) and 40,196 contemporary controls representative of the childhood population in France. The proximity of the vines (probability of presence within 200, 500, and 1,000 m ) and the viticulture density (area devoted to vines within 1,000 m ) were evaluated around the geocoded addresses in a geographic information system combining three national land use maps. Logistic regression models were used to estimate odds ratios (ORs) for all AL and for the lymphoblastic (ALL) and myeloid (AML) subtypes. Heterogeneity between regions was studied by stratified analyses. Sensitivity analyses were carried out to take into account, in particular, geocoding uncertainty, density of other crops and potential demographic and environmental confounders.

RESULTS

In all, about 10% of the controls lived within 1 km of vines. While no evidence of association between proximity to vines and AL was found, viticulture density was positively associated with ALL [OR = 1.05 (1.00-1.09) for a 10% increase in density], with a statistically significant heterogeneity across regions. No association with AML was observed. The results remained stable in all the sensitivity analyses.

CONCLUSION

We evidenced a slight increase in the risk of ALL in children living in areas with high viticulture density. This finding supports the hypothesis that environmental exposure to pesticides may be associated with childhood ALL. https://doi.org/10.1289/EHP12634.

Maternal and Paternal Household Pesticide Exposure During Pregnancy and Risk of Childhood Acute Lymphoblastic Leukemia

OBJECTIVE

The aim of this study was to investigate whether risk estimates for childhood acute lymphoblastic leukemia change when restricting model comparison groups to "nonpesticide exposure" (NPE10) households.

METHODS

Cases ( n = 1810) 15 years or younger were identified through Children's Cancer Group institutions between 1989 and 1993 and age-/sex-matched to controls ( n = 1951). Household pesticide use during pregnancy/month prior was collected via telephone. NPE10 comparison group reporting no parental exposure to 10 pesticide classes was identified.

RESULTS

Adjusted odds ratios increased from 15% to 49% when limiting the comparison to NPE10. Maternal termite insecticide exposure was associated with greatest risk (adjusted odds ratio, 4.21; 95% confidence interval, 2.00-8.88). There was minimal evidence of interaction by child sex or occupational pesticide exposure, and no monotonic dose-response pattern with frequency of use (times per year).

CONCLUSIONS

Elevated risks are consistent with published pooled-/meta-analyses and DNA damage. The consistency and magnitude of these associations warrant product labeling, exposure reduction interventions, or both.

Residential proximity to petrol stations and risk of childhood leukemia

Petrol stations emit benzene and other contaminants that have been associated with an increased risk of childhood leukemia. We carried out a population-based case-control study in two provinces in Northern Italy. We enrolled 182 cases of childhood leukemia diagnosed during 1998-2019 and 726 age- and sex-matched population controls. We geocoded the addresses of child residences and 790 petrol stations located in the study area. We estimated leukemia risk according to distance from petrol stations within a 1000 m buffer and amount of supplied fuel within a buffer of 250 m from the child's residence. We used conditional logistic regression models to approximate risk ratios (RRs) and 95% confidence intervals (CIs) for associations of interest, adjusted for potential confounders. We also modeled non-linear associations using restricted cubic splines. In secondary analyses, we restricted to acute lymphoblastic leukemia (ALL) cases and stratifed by age (<5 and ≥5 years). Compared with children who lived≥1000 m from a petrol station, the RR was 2.2 (95% CI 0.5-9.4) for children living<50 m from nearest petrol station. Associations were stronger for the ALL subtype (RR=2.9, 95% CI 0.6-13.4) and among older children (age≥5 years: RR=4.4, 95% CI 0.6-34.1; age<5 years: RR=1.6, 95% CI 0.1-19.4). Risk of leukemia was also greater (RR=1.6, 95% CI 0.7-3.3) among the most exposed participants when assigning exposure categories based on petrol stations located within 250 m of the child's residence and total amount of gasoline delivered by the stations. Overall, residence within close proximity to a petrol station, especially one with more intense refueling activity, was associated with an increased risk of childhood leukemia, though associations were imprecise.

Sauver JL, Rocca WA. Integrating Environmental Data with Medical Data in a Records-Linkage System to Explore Groundwater Nitrogen Levels and Child Health Outcomes

Background: The Rochester Epidemiology Project (REP) medical records-linkage system offers a unique opportunity to integrate medical and residency data with existing environmental data, to estimate individual-level exposures. Our primary aim was to provide an archetype of this integration. Our secondary aim was to explore the association between groundwater inorganic nitrogen concentration and adverse child and adolescent health outcomes. Methods: We conducted a nested case-control study in children, aged seven to eighteen, from six counties of southeastern Minnesota. Groundwater inorganic nitrogen concentration data were interpolated, to estimate exposure across our study region. Residency data were then overlaid, to estimate individual-level exposure for our entire study population (n = 29,270). Clinical classification software sets of diagnostic codes were used to determine the presence of 21 clinical conditions. Regression models were adjusted for age, sex, race, and rurality. Results: The analyses support further investigation of associations between nitrogen concentration and chronic obstructive pulmonary disease and bronchiectasis (OR: 2.38, CI: 1.64-3.46) among boys and girls, thyroid disorders (OR: 1.44, CI: 1.05-1.99) and suicide and intentional self-inflicted injury (OR: 1.37, CI: >1.00-1.87) among girls, and attention deficit conduct and disruptive behavior disorders (OR: 1.34, CI: 1.24-1.46) among boys. Conclusions: Investigators with environmental health research questions should leverage the well-enumerated population and residency data in the REP.

Exposures to pesticides and risk of cancer: Evaluation of recent epidemiological evidence in humans and paths forward

Knowledge of the role in cancer etiology of environmental exposures as pesticides is a prerequisite for primary prevention. We review 63 epidemiological studies on exposure to pesticides and cancer risk in humans published from 2017 to 2021, with emphasis on new findings, methodological approaches, and gaps in the existing literature. While much of the recent evidence suggests causal relationships between pesticide exposure and cancer, the strongest evidence exists for acute myeloid leukemia (AML) and colorectal cancer (CRC), diseases in which the observed associations were consistent across several studies, including high-quality prospective studies and those using biomarkers for exposure assessment, with some observing dose-response relationships. Though high-quality studies have been published since the IARC monograph on organophosphate insecticides in 2017, there are still gaps in the literature on carcinogenic evidence in humans for a large number of pesticides. To further knowledge, we suggest leveraging new techniques and methods to increase sensitivity and precision of exposure assessment, incorporate multi-omics data, and investigate more thoroughly exposure to chemical mixtures. There is also a strong need for better and larger population-based cohort studies that include younger and nonoccupationally exposed individuals, particularly during developmental periods of susceptibility. Though the existing evidence has limitations, as always in science, there is sufficient evidence to implement policies and regulatory action that limit pesticide exposure in humans and, hence, further prevent a significant burden of cancers.

Use and storage of pesticides at home in France (the Pesti'home survey 2014)

Some epidemiological studies have raised health concerns following the chronic exposure of pregnant women and children to pesticides in the domestic environment. In France very little is known about potential exposure to pesticides at home. An observational study called Pesti'home was carried out in continental France between July and November 2014. The residential use of pesticides was investigated and an inventory of pesticides and active ingredients used and stored at home was drawn up. Plant protection products, biocides, and human and animal external pest control products were listed during face-to-face interviews. A random sample of households including at least one adult (18-79 years old) was selected following a two-stage stratified random sampling method using the national census database. Within each household, an adult was appointed to answer survey questions. Data related to the interviewee's sociodemographic and housing characteristics, the reported use of pesticides at home, and a visual inventory of all stored pesticides were collected. Overall, 1507 households participated. The participation rate was between 36% and 57% according to the definition chosen. Over the previous 12 months, 75% of households declared that they had used at least one pesticide. Households who used and stored at least one product most frequently used an insecticide (84%). The active ingredients most frequently used by these households as insecticides were pyrethroids, namely tetramethrin and permethrin. The Pesti'home survey collected detailed data on the residential use of pesticides for risk assessment at national and European levels.

Toxic effects of pesticides on cellular and humoral immunity: an overview

People are exposed to pesticides through food, drinking water, and the environment. These compounds are associated with several disorders, such as inflammatory diseases, rheumatoid arthritis, cancer, and a condition related to metabolic syndrome. The immunotoxicants or immunotoxic compounds can cause a wide variety of effects on immune function, altering humoral immunity and cell-mediated immunity, resulting in adverse effects to the body. Here, immune system disorders are highlighted because they are closely linked to multiple organs, including the nervous, endocrine, reproductive, cardiovascular, and respiratory systems, leading to transient or permanent changes. Therefore, this study reviewed the mechanisms involved in the immunotoxicity of fungicides, herbicides, and insecticides in cells, animals, and humans in the past 11 years. According to the studies analyzed, the pesticides interfere with innate and adaptive immune functions, but the effects observed mainly on cellular and humoral immunity were highlighted. These compounds affected specific immune cells, causing apoptosis, changes in factor nuclear kappa B (NF-κB) expression, pro-inflammatory factors interleukin 6 (IL-6), interleukin 8 (IL-8), interferon-gamma (IFN-γ), chemokines (CXCL-c1c), and anti-inflammatory factor, such as interleukin 10 (IL-10). To verify the threats of these compounds, new evaluations with immunotoxicological biomarkers are necessary. HighlightsPesticides interfere with the innate and adaptive immune response.Cells, animals and human studies demonstrate the immunotoxicity of pesticides in the cellular and humoral immune response.Fungicides, herbicides, and insecticides alter the immune system by various mechanisms, such as pro-inflammatory and anti-inflammatory factors.

Characterization of Urinary Pesticide Metabolite Concentrations of Pregnant Women in Suriname

Prenatal exposure to pesticides and the association with adverse health outcomes have been examined in several studies. However, the characterization of pesticide exposure among Surinamese women during pregnancy has not been assessed. As part of the Caribbean Consortium of Research in Environmental and Occupational Health research program, 214 urine samples were collected from pregnant women living in three regions in Suriname with different agricultural practices: capital Paramaribo, the rice producing district Nickerie, and the tropical rainforest, the Interior. We used isotope dilution tandem mass spectrometry to quantify urinary concentrations of biomarkers of three pesticide classes, including phenoxy acid herbicides and organophosphate and pyrethroid insecticides, all of which are commonly used in agricultural and residential settings in Suriname. We observed that participants residing in Nickerie had the highest urinary metabolite concentrations of 2,4-dichlorophenoxyacetic acid and pyrethroids compared to those from Paramaribo or the Interior. Paramaribo had the highest concentrations of organophosphate metabolites, specifically dialkyl phosphate metabolites. Para-nitrophenol was detected in samples from Paramaribo and the Interior. Samples from Nickerie had higher median urinary pesticide concentrations of 2,4-dichlorophenoxyacetic acid (1.06 μg/L), and the following metabolites, 3,5,6-trichloro-2-pyridinol (1.26 μg/L), 2-isopropyl-4-methyl-6-hydroxypyrimidine (0.60 μg/L), and 3-phenoxybenzoic acid (1.34 μg/L), possibly due to residential use and heavy rice production.

Domestic Exposure to Chemicals in Household Products, Building Materials, Decoration, and Pesticides: Guidelines for Interventions During the Perinatal Period from the French National College of Midwives

INTRODUCTION

We are exposed to numerous pollutants inside our homes. The perinatal period represents a particular window of vulnerability during which these exposures can have negative health effects over a more or less long term. The objective of this article is to formulate guidelines for health care professionals and intended for parents to reduce exposure to chemical pollutants at home, based on the scientific literature and already existing guidelines.

METHODS

We have followed the methodological procedures set forth by the French authority for health (HAS) to establish guidelines to limit exposure to pollutants in homes. This narrative review of the scientific literature was conducted with two principal objectives: (1) to identify priority substances emitted within homes and that have a reprotoxic potential and (2) to identify measures to limit exposure to these residential pollutants. The guidelines were developed from the data in the literature and from advice already made available by diverse institutions about environmental health during the perinatal period.

RESULTS

Domestic pollutants are numerous and come from both common (that is, shared, eg, painting, cleaning, and maintenance work) and specific (use of household pesticides) sources. Numerous pollutants are suspected or known to produce developmental toxicity, that is, to be toxic to children during developmental stages. Removing some products from the home, protecting the vulnerable (ie, pregnant women and young children) from exposure, and airing the home are among the preventive measures proposed to limit exposure to these chemical substances.

CONCLUSION

Health care professionals can provide advice to parents during the perinatal period to diminish exposure to household pollutants. The lack of interventional studies nonetheless limits the level of evidence for most of these recommendations.

Residential proximity to croplands at birth and childhood leukaemia

Background

Domestic and parental occupational pesticide exposures are suspected of involvement in the occurrence of childhood acute leukaemia (AL), but the role of exposure to agricultural activities is little known. In a previous ecological study conducted in France, we observed an increase in acute lymphoblastic leukaemia (ALL) incidence rate with increasing viticulture density in the municipalities of residence at diagnosis.

Objectives

This study aimed to test the hypothesis that residential proximity to croplands at birth increases the risk of childhood AL, with a particular focus on vineyards.

Methods

We identified all the primary AL cases diagnosed before the age of 15 years in the cohorts of children born in the French municipalities between 1990 and 2015. We estimated crop densities in each municipality of residence at birth using agricultural census data, for ten crop types. Variations in standardized incidence ratios (SIR) were evaluated with Poisson regression models, for all AL, ALL and acute myeloid leukaemia (AML), separately.

Results

Among the 19,809,700 children born and residing in mainland France at birth in 1990–2015, 8,747 AL cases (7,236 ALL and 1,335 AML) were diagnosed over the period. We did not evidence any statistically significant positive association between total crop density or any specific crop density in the municipality of residence at birth and all AL, ALL or AML. Interestingly, we observed a higher ALL incidence rate in the municipalities with the highest viticulture densities (SIR = 1.25 95%CI [1.01–1.54]). Adjusting for the main potential confounders did not change the results.

Conclusion

Our study does not support the hypothesis that residential proximity to croplands, particularly vineyards, around birth plays a role in childhood leukaemia. The slightly higher ALL incidence rate in children born in the municipalities with the highest viticulture densities may reflect the previously-observed association at diagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12940-022-00909-0.

Commercial outdoor plant nurseries as a confounder for electromagnetic fields and childhood leukemia risk

BACKGROUND

Close residential proximity to powerlines and high magnetic fields exposure may be associated with elevated childhood leukemia risks as reported by prior studies and pooled analyses. Magnetic fields exposure from high-voltage powerlines is associated with proximity to these powerlines and consequently with any factor varying with distance. Areas underneath powerlines in California may be sites for commercial plant nurseries that can use pesticides, a potential childhood leukemia risk factor.

OBJECTIVES

Assess if potential pesticide exposure from commercial plant nurseries is a confounder or interacts with proximity or magnetic fields exposure from high-voltage powerlines to increase childhood leukemia risk.

METHODS

A comprehensive childhood leukemia record-based case-control study with 5788 cases and 5788 controls (born and diagnosed in California, 1986-2008) was conducted. Pesticide, powerline, and magnetic field exposure assessment utilized models that incorporated geographical information systems, aerial satellite images, site visits and other historical information.

RESULTS

The relationship for calculated fields with childhood leukemia (odds ratio (OR) 1.51, 95% confidence interval (CI) 0.70-3.23) slightly attenuated when controlling for nursery proximity (OR 1.43, 95% CI 0.65-3.16) or restricting analysis to subjects living far (>300 m) from nurseries (OR 1.43, 95% CI 0.79-2.60). A similar association pattern was observed between distance to high-voltage powerlines and childhood leukemia. The association between nursery proximity and childhood leukemia was unchanged or only slightly attenuated when controlling for calculated fields or powerline distance; ORs remained above 2 when excluding subjects with high calculated fields or close powerline proximity (OR 2.16, 95% CI 0.82-5.67 and OR 2.15, 95% CI 0.82-5.64, respectively). The observed relationships were robust to different time periods, reference categories, and cut points.

DISCUSSION

Close residential proximity to nurseries is suggested as an independent childhood leukemia risk factor. Our results do not support plant nurseries as an explanation for observed childhood leukemia risks for powerline proximity and magnetic fields exposure, although small numbers of subjects concurrently exposed to high magnetic fields, close powerline proximity and plant nurseries limited our ability to fully assess potential confounding.

Regional and national burden of leukemia and its attributable burden to risk factors in 21 countries and territories of North Africa and Middle East, 1990-2019: results from the GBD study 2019

PURPOSE

Regional and national data on leukemia's burden provide a better comprehension of leukemia's trends and are vital for policy-makers for better allocation of the resources. This study reports the burden of leukemia, and the attributed burden to its risk factors in 21 countries and territories of the North Africa and Middle East.

METHODS

Data from cancer registration, scientific literature, survey, and reports were the input to estimate the burden of leukemia. In addition, the burden of attributable risk factors with evidence of causation with leukemia was calculated using the comparative risk assessment framework. All measures are reported as counts and rates divided by sex and specific age groups.

RESULTS

In 2019, there were 39,297 (95% uncertainty interval: 32,617-45,056) incident cases of leukemia with an age-standardized rate (ASR) of 7.8 (6.5-8.8) per 100,000 in the region. There were also 25,143 (21,109-28,826) deaths and 1,011,555 (822,537-1,173,621) DALYs attributed to Leukemia with an ASR of 5.4 (4.6-6.1) per 100,000 and 183.4 (150.7-211.2) per 100,000, respectively. Years of life lost (YLLs) (179.4 [147.2-206.7]) were accountable for the major part of DALYs. All count measures increased, while all the ASRs decreased during 1990-2019. The Syrian Arab Republic, Qatar, and Afghanistan had the highest ASR incidence, mortality, and DALYs rate in 2019. Incidence, DALYs, and prevalence rates were higher in males of all age groups except under five, and the highest rates were observed in +75 age group. Four major risk factors for leukemia were smoking, high body mass index, occupational exposure to benzene, and formaldehyde.

CONCLUSION

Despite the reduction in age-standardized rates of incidence and mortality, the burden of leukemia has increased steadily, due to population growth and aging. Notable variations exist between age-standardized rates in region's countries.

Paediatric pre-B acute lymphoblastic leukaemia-derived exosomes regulate immune function in human T cells

Exosomes derived from solid tumour cells are involved in immune suppression, angiogenesis and metastasis; however, the role of leukaemia‐derived exosomes has less been investigated. Hence, changes in immune response‐related genes and human T cells apoptosis co‐incubated with exosomes isolated from patients' pre‐B cell acute lymphoblastic leukaemia were evaluated in this in vitro study. Vein blood sample was obtained from each newly diagnosed acute lymphoblastic leukaemia (ALL) patient prior any therapy. ALL serum exosomes were isolated by ultrafiltration and characterized using Western blotting and transmission electron microscopy. Exosomes were then co‐incubated with T lymphocytes and the gene expressions, as well as functions of human T cells were quantified by qRT‐PCR. Apoptosis and caspase‐3 and caspase‐9 protein expression were also evaluated by flowcytometry and Western blotting analysis, respectively. Exosomes isolated from ALL patients affected T lymphocytes and elevated the apoptosis. Moreover, these exosomes altered the T cells profile into regulatory type by increasing the expression of FOXP3 and Tregs‐related cytokines, including TGF‐B and IL‐10. The expression level of Th17‐related transcription factors (RoRγt) and interleukins (IL‐17 and IL‐23) decreased after this treatment. According to our findings, exosomes derived from ALL patients' sera carry immunosuppressive molecules, indicating the possible effect of exosomes as liquid biomarkers for cancer staging.

High Levels of Organochlorines Are Associated with Induction of ABL1 Promoter Methylation in Children with Acute Lymphoblastic Leukemia

Exposure to organochlorines is associated with epigenetic changes, including methylation change in the promoter of tumor suppressor genes, thereby leading to cancer induction. The aim of this study was to investigate the relationship between organochlorine pesticides (OCPs) and ABL1 promoter methylation in child patients with acute lymphoblastic leukemia (ALL) and the control group. The methylation rate of the ABL1 promoter was evaluated using the methylation-specific polymerase chain reaction method, and the level of OCPs in patients with ALL and healthy children was measured using gas chromatography. ABL1 promoter hypermethylation was observed in 64% of ALL patients and 28.5% of children in the control group. The level of OCPs in children with methylated ABL1 promoters was significantly higher than that in children with nonmethylated ABL1 promoters (p < 0.05). Our findings suggest that OCPs, especially alpha-hexachlorocyclohexane, beta-hexachlorocyclohexane, gamma-hexachlorocyclohexane, 2,4 dichlorodiphenyldichloroethylene, and 4,4 dichlorodiphenyltrichloroethane may induce methylation at the ABL1 promoter level, thereby preventing the normal expression of the ABL1 gene. As a result, the reduced expression of ABL1 (a tumor suppressor) gene due to the hypermethylation of its promoter leads to the disruption of normal biological processes, thus making cells vulnerable to oncogenic factors.

Maternal pesticide exposure and its relation to childhood cancer: an umbrella review of meta-analyses

This umbrella review summarizes the available meta-analyses elucidating the effects of maternal pesticide exposure on adverse health outcomes in children particularly the risk of childhood cancer. A literature search was conducted on PubMed and Scopus with 10-years temporal restriction and with search terms of ('pesticides') and ('maternal' or 'pregnancy' or 'gestational' or 'perinatal' or 'children' or 'infants' or 'birth weight' or 'gestational age' or 'cancer' or 'tumor' or 'malignancy' or 'carcinoma') and ('meta-analysis' or 'systematic review'). Using relative risk estimates, e.g., odds ratio (OR), relative risk (RR), ß coefficients, and 95% confidence interval (CI) as a prerequisite for inclusion/exclusion criteria a total of 19 eligible meta-analyses were included. The results showed that maternal domestic/occupational pesticide exposure increases the risk for childhood leukaemia. The overall OR regarding the risk of pesticide exposure and leukaemia was 1.23 to 1.57 with heterogeneity I² values that varied between 12.9% and 73%. Some studies found that exposure to dichlorodiphenyldichloroethylene (p,p´-DDE) and polychlorinated biphenyls (PCB-153) pesticides appears to decrease infant birth weight to some extent [p,p´-DDE (ß = -0.007 to -0.008)] and [PCB-153 (ß = -0.15 to -0.17)]Needing more studies on this relationship, our study found that pesticide exposure is a risk factor for leukaemia in children.

Does Insect Aversion Lead to Increased Household Pesticide Use?

In many human societies, domestic insect pests often evoke feelings of disgust, fear and aversion. These common feelings may translate to increased use of household pesticides. No study has ever explored this possibility and consequently, efforts to mitigate public exposure to domestic pesticides typically focus on addressing knowledge gaps. We tested the hypothesis that negative emotions toward insects may motivate people to use pesticides, by interviewing 70 participants and assessing their insect aversion levels using a computerized test. Contrary to our hypothesis, we found no effect of insect aversion on pesticide use. However, we did find that personal attributes and preferences such as wishing to avoid exposure to toxic chemicals, being vegetarian and taking frequent nature walks reduced pesticide use, in addition to low infestation levels and physical attributes of the housing unit. We emphasize the importance of conducting future studies in various societies, where insect aversion and other factors may have different effects on household pesticide use. Such studies may provide culture-specific insights that could foster the development of next-generation urban IPM (Integrated Pest Management) public education programs, which will address not only knowledge gaps, but also emotional aspects and personal attributes that lead to unnecessary or excessive use of household pesticides.

Complex Elucidation of Cells-of-Origin in Pediatric Soft Tissue Sarcoma: From Concepts to Real Life, Hide-and-Seek through Epigenetic and Transcriptional Reprogramming

Soft tissue sarcoma (STS) comprise a large group of mesenchymal malignant tumors with heterogeneous cellular morphology, proliferative index, genetic lesions and, more importantly, clinical features. Full elucidation of this wide diversity remains a central question to improve their therapeutic management and the identity of cell(s)-of-origin from which these tumors arise is part of this enigma. Cellular reprogramming allows transitions of a mature cell between phenotypes, or identities, and represents one key driver of tumoral heterogeneity. Here, we discuss how cellular reprogramming mediated by driver genes in STS can profoundly reshape the molecular and morphological features of a transformed cell and lead to erroneous interpretation of its cell-of-origin. This review questions the fact that the epigenetic context in which a genetic alteration arises has to be taken into account as a key determinant of STS tumor initiation and progression. Retracing the cancer-initiating cell and its clonal evolution, notably via epigenetic approach, appears as a key lever for understanding the origin of these tumors and improving their clinical management.

Genetic Biomarkers and Their Clinical Implications in B-Cell Acute Lymphoblastic Leukemia in Children

Acute lymphoblastic leukemia (ALL) is a heterogeneous group of hematologic malignancies characterized by abnormal proliferation of immature lymphoid cells. It is the most commonly diagnosed childhood cancer with an almost 80% cure rate. Despite favorable survival rates in the pediatric population, a significant number of patients develop resistance to therapy, resulting in poor prognosis. ALL is a heterogeneous disease at the genetic level, but the intensive development of sequencing in the last decade has made it possible to broaden the study of genomic changes. New technologies allow us to detect molecular changes such as point mutations or to characterize epigenetic or proteomic profiles. This process made it possible to identify new subtypes of this disease characterized by constellations of genetic alterations, including chromosome changes, sequence mutations, and DNA copy number alterations. These genetic abnormalities are used as diagnostic, prognostic and predictive biomarkers that play an important role in earlier disease detection, more accurate risk stratification, and treatment. Identification of new ALL biomarkers, and thus a greater understanding of their molecular basis, will lead to better monitoring of the course of the disease. In this article, we provide an overview of the latest information on genomic alterations found in childhood ALL and discuss their impact on patients' clinical outcomes.

Environmental Risk Factors for Childhood Acute Lymphoblastic Leukemia: An Umbrella Review

Leukemia is the most common type of cancer among children and adolescents worldwide. The aim of this umbrella review was (1) to provide a synthesis of the environmental risk factors for the onset of childhood acute lymphoblastic leukemia (ALL) by exposure window, (2) evaluate their strength of evidence and magnitude of risk, and as an example (3) estimate the prevalence in the German population, which determines the relevance at the population level. Relevant systematic reviews and pooled analyses were identified and retrieved through PubMed, Web of Science databases and lists of references. Only two risk factors (low doses of ionizing radiation in early childhood and general pesticide exposure during maternal preconception/pregnancy) were convincingly associated with childhood ALL. Other risk factors including extremely low frequency electromagnetic field (ELF-MF), living in proximity to nuclear facilities, petroleum, benzene, solvent, and domestic paint exposure during early childhood, all showed some level of evidence of association. Maternal consumption of coffee (high consumption/>2 cups/day) and cola (high consumption) during pregnancy, paternal smoking during the pregnancy of the index child, maternal intake of fertility treatment, high birth weight (≥4000 g) and caesarean delivery were also found to have some level of evidence of association. Maternal folic acid and vitamins intake, breastfeeding (≥6 months) and day-care attendance, were inversely associated with childhood ALL with some evidence. The results of this umbrella review should be interpreted with caution; as the evidence stems almost exclusively from case-control studies, where selection and recall bias are potential concerns, and whether the empirically observed association reflect causal relationships remains an open question. Hence, improved exposure assessment methods including accurate and reliable measurement, probing questions and better interview techniques are required to establish causative risk factors of childhood leukemia, which is needed for the ultimate goal of primary prevention.

Multiple neonicotinoids in children's cerebro-spinal fluid, plasma, and urine

BACKGROUND

Neonicotinoids (NN) are selective neurotoxic pesticides that bind to insect but also mammal nicotinic acetycholine receptors (nAChRs). As the most widely used class of insecticides worldwide, they are ubiquitously found in the environment, wildlife, and foods, and thus of special concern for their impacts on the environment and human health. nAChRs are vital to proper brain organization during the prenatal period and play important roles in various motor, emotional, and cognitive functions. Little is known on children's contamination by NN. In a pilot study we tested the hypothesis that children's cerebro-spinal fluid (CSF) can be contaminated by NN.

METHODS

NN were analysed in leftover CSF, blood, and urine samples from children treated for leukaemias and lymphomas and undergoing therapeutic lumbar punctions. We monitored all neonicotinoids approved on the global market and some of their most common metabolites by ultra-high performance liquid chromatography-tandem mass spectrometry.

RESULTS

From August to December 2020, 14 children were consecutively included in the study. Median age was 8 years (range 3-18). All CSF and plasma samples were positive for at least one NN. Nine (64%) CSF samples and 13 (93%) plasma samples contained more than one NN. Thirteen (93%) CSF samples had N-desmethyl-acetamiprid (median concentration 0.0123, range 0.0024-0.1068 ng/mL), the major metabolite of acetamiprid. All but one urine samples were positive for ≥ one NN. A statistically significant linear relationship was found between plasma/urine and CSF N-desmethyl-acetamiprid concentrations.

CONCLUSIONS

We have developed a reliable analytical method that revealed multiple NN and/or their metabolites in children's CSF, plasma, and urine. Our data suggest that contamination by multiple NN is not only an environmental hazard for non-target insects such as bees but also potentially for children.

Pesticide exposure and related health problems among farmworkers' children: a case-control study in southeast Iran

Pesticides are potentially hazardous chemicals that can cause injury to human health and the environment. The purpose of this study was to evaluate organophosphate pesticides (OPPs) and organochlorine pesticides (OCPs) exposure in farmworkers' children aged 6 to 11 years in Jiroft city in southeastern Iran. One hundred twenty farmworkers' children as case and 53 non-farmworkers' children aged 6 to 11 years as control were selected and the serum levels of OCPs were measured by using gas chromatography in all participants. In addition, erythrocyte acetylcholinesterase (AChE) and arylesterase activity of paraoxonase-1 (PON-1) were measured to evaluate OPPs effects. Catalase (CAT), superoxide dismutase3 (SOD3), glutathione peroxidase (GPx3) activities, and the levels of serum malondialdehyde (MDA), total antioxidant capacity (TAC), nitric oxide (NO), and protein carbonyl (PC) were measured to investigate OCPs and OPPs effects on oxidative stress (OS). The serum levels of beta-HCH, 4,4 DDE, and 4,4 DDT in the case group were significantly higher than the control group. In addition, in the case group, AChE, PON-1, CAT, SOD3, and GPx3 activities and the levels TAC were significantly lower, while MDA, PC, and NO levels were significantly higher than the control group. OCPs as illegal pesticides are present in southeast Iran and children are exposed to OCPs and OPPs in the studied area. In addition, higher serum levels of pesticides may be a major contributor in OS development, as a cause of many diseases.

Residential exposure to carbamate, organophosphate, and pyrethroid insecticides in house dust and risk of childhood acute lymphoblastic leukemia

BACKGROUND

Self-reported residential use of pesticides has consistently been associated with increased risk of childhood leukemia. However, these studies were limited in their ability to identify specific insecticide active ingredients that were associated with risk.

OBJECTIVE

We used household carpet dust measurements of 20 insecticides (two carbamate, 10 organophosphate, two organochlorine, and six pyrethroid) as indicators of exposure and evaluated associations with the risk of childhood acute lymphoblastic leukemia (ALL).

METHODS

We conducted a population-based case-control study of 252 ALL cases diagnosed from 1999 to 2007 and 306 birth certificate controls from 35 counties in Central and Northern California. Carpet dust was collected at a second interview (2001-2007) for cases who had not moved since diagnosis (comparable reference date for controls) using a specialized vacuum cleaner in the room where the child spent most of their time or from the household vacuum. Insecticides were categorized as detected (yes/no), or as tertiles or quartiles of their distributions among controls. We calculated odds ratios (OR) and 95% confidence intervals (CI) using unconditional logistic regression adjusting for demographic characteristics, interview year, and season of dust collection.

RESULTS

Permethrin, chlorpyrifos, diazinon, and carbaryl were the most frequently detected insecticide active ingredients. When we compared the highest quartile to the lowest or to non-detections, there was no association with ALL for permethrin (OR Q4 vs. Q1 = 0.81; 95% CI 0.50-1.31), carbaryl (OR Q4 vs. non-detects = 0.61, 95% CI 0.34-1.08) or chlorpyrifos (OR Q4 vs. Q1 = 0.60; 95% CI 0.36-1.00). The highest quartile of diazinon concentration was inversely associated with risk in the single pesticide model but without a monotonic exposure-response (p-trend = 0.14). After adjusting for other common insecticides, the OR was not significant (OR Q4 vs. Q1 = 0.58; 95% CI 0.33-1.05). None of the other insecticides were associated with risk.

CONCLUSION

Our results should be interpreted within the limitations of the case-control study design including the use of a single post-diagnosis dust sample and restriction to residentially stable participants, which may have resulted in selection bias. Although difficult to implement, additional studies with assessment of exposure to insecticide active and non-active ingredients are necessary to elucidate the role of these common exposures in childhood leukemia risk.

Exposure to pesticides and childhood leukemia risk: A systematic review and meta-analysis

Despite the abundance of epidemiological evidence concerning the association between pesticide exposure and adverse health outcomes including acute childhood leukemia (AL), evidence remains inconclusive, and is inherently limited by heterogeneous exposure assessment and multiple statistical testing. We performed a literature search of peer-reviewed studies, published until January 2021, without language restrictions. Summary odds ratios (OR) and 95% confidence intervals (CI) were derived from stratified random-effects meta-analyses by type of exposure and outcome, exposed populations and window of exposure to address the large heterogeneity of existing literature. Heterogeneity and small-study effects were also assessed. We identified 55 eligible studies (n = 48 case-control and n = 7 cohorts) from over 30 countries assessing >200 different exposures of pesticides (n = 160,924 participants). The summary OR for maternal environmental exposure to pesticides (broad term) during pregnancy and AL was 1.88 (95%CI: 1.15-3.08), reaching 2.51 for acute lymphoblastic leukemia (ALL; 95%CI: 1.39-4.55). Analysis by pesticide subtype yielded an increased risk for maternal herbicide (OR: 1.41, 95%CI: 1.00-1.99) and insecticide (OR: 1.60, 95%CI: 1.11-2.29) exposure during pregnancy and AL without heterogeneity (p = 0.12-0.34). Meta-analyses of infant leukemia were only feasible for maternal exposure to pesticides during pregnancy. Higher magnitude risks were observed for maternal pesticide exposure and infant ALL (OR: 2.18, 95%CI: 1.44-3.29), and the highest for infant acute myeloid leukemia (OR: 3.42, 95%CI: 1.98-5.91). Overall, the associations were stronger for maternal exposure during pregnancy compared to childhood exposure. For occupational or mixed exposures, parental, and specifically paternal, pesticide exposure was significantly associated with increased risk of AL (ORparental: 1.75, 95%CI: 1.08-2.85; ORpaternal: 1.20, 95%CI: 1.07-1.35). The epidemiological evidence, supported by mechanistic studies, suggests that pesticide exposure, mainly during pregnancy, increases the risk of childhood leukemia, particularly among infants. Sufficiently powered studies using repeated biomarker analyses are needed to confirm whether there is public health merit in reducing prenatal pesticide exposure.

Passive environmental residential exposure to agricultural pesticides and hematological malignancies in the general population: a systematic review

Incidence rates of hematological malignancies have been constantly increasing over the past 40 years. In parallel, an expanding use of agricultural pesticides has been observed. Only a limited number of studies investigated the link between hematological malignancies risk and passive environmental residential exposure to agricultural pesticides in the general population. The purpose of our review was to summarize the current state of knowledge on that question. A systematic literature search was conducted using PubMed and Scopus databases. We built a scoring scale to appraise relevance of each selected articles. We included 23 publications: 13 ecological studies, 9 case-control studies and a cohort study. Positive associations were reported between hematological malignancies and individual pesticides, pesticide groups, all pesticides without distinction, or some crop types. Relevance score was highly various across studies regardless of their design. Children studies were the majority and had overall higher relevance scores. The effect of passive environmental residential exposure to agricultural pesticides on hematological malignancies risk is suggested by the literature. The main limitation of the literature available is the high heterogeneity across studies, especially in terms of exposure assessment approach. Further studies with high methodological relevance should be conducted.

Household pesticide exposure: an online survey and shelf research in the Metropolitan Region of Rio de Janeiro, Brazil

This study aimed to estimate household pesticide exposure in adult individuals in the Metropolitan Region of Rio de Janeiro, Brazil, and to verify the accessibility of these products in local and online businesses. The data were collected by an online questionnaire (1,015 responses) and a shelf survey in physical and online stores. Among the responses analyzed, 87.5% used pesticides in the previous year, most of which against mosquitoes (64.7%). The most common application method was aerosol spray (38.1%), and the most frequent places of use were bedrooms (29.7%) and living rooms (22.1%). About 30% of respondents reported invasion of pests, and the most common pests were ants (79.1%) and cockroaches (40.4%). Service area (71.6%) and kitchen (17.5%) were the most common storage locations. Approximately 91% of those who lived with children aged under 18 used pesticides. The use of chemical group of pyrethroids prevailed (81.6%), and 90.8% of the reportedly used products are class II [55.7% (highly toxic)] or class III [35.1% (medium toxic)]. The most significant amount of purchased products was in the pest category, followed by mosquitoes. More variety of products were available in online stores than in physical stores. The high exposure of the population to pesticides at household is a public health issue and confirms the need for studies that better assess the risks and consequences of chronic and low-dose exposure to these substances. It is essential to inform the population about the uncertainties and potential risks of indiscriminate use so that they can choose whether to use pesticides in their households.

Environmental Risk Factors and Health: An Umbrella Review of Meta-Analyses

Background: Environmental health is a growing area of knowledge, continually increasing and updating the body of evidence linking the environment to human health. Aim: This study summarizes the epidemiological evidence on environmental risk factors from meta-analyses through an umbrella review. Methods: An umbrella review was conducted on meta-analyses of cohort, case-control, case-crossover, and time-series studies that evaluated the associations between environmental risk factors and health outcomes defined as incidence, prevalence, and mortality. The specific search strategy was designed in PubMed using free text and Medical Subject Headings (MeSH) terms related to risk factors, environment, health outcomes, observational studies, and meta-analysis. The search was limited to English, Spanish, and French published articles and studies on humans. The search was conducted on September 20, 2020. Risk factors were defined as any attribute, characteristic, or exposure of an individual that increases the likelihood of developing a disease or death. The environment was defined as the external elements and conditions that surround, influence, and affect a human organism or population’s life and development. The environment definition included the physical environment such as nature, built environment, or pollution, but not the social environment. We excluded occupational exposures, microorganisms, water, sanitation and hygiene (WASH), behavioral risk factors, and no-natural disasters. Results: This umbrella review found 197 associations among 69 environmental exposures and 83 diseases and death causes reported in 103 publications. The environmental factors found in this review were air pollution, environmental tobacco smoke, heavy metals, chemicals, ambient temperature, noise, radiation, and urban residential surroundings. Among these, we identified 65 environmental exposures defined as risk factors and 4 environmental protective factors. In terms of study design, 57 included cohort and/or case-control studies, and 46 included time-series and/or case-crossover studies. In terms of the study population, 21 included children, and the rest included adult population and both sexes. In this review, the largest body of evidence was found in air pollution (91 associations among 14 air pollution definitions and 34 diseases and mortality diagnoses), followed by environmental tobacco smoke with 24 associations. Chemicals (including pesticides) were the third larger group of environmental exposures found among the meta-analyses included, with 19 associations. Conclusion: Environmental exposures are an important health determinant. This review provides an overview of an evolving research area and should be used as a complementary tool to understand the connections between the environment and human health. The evidence presented by this review should help to design public health interventions and the implementation of health in all policies approach aiming to improve populational health.

Perceptions, Knowledge, and Practices Concerning Indoor Environmental Pollution of Parents or Future Parents

Indoor pollutants can have short- and long-term health effects, especially if exposure occurs during prenatal life or early childhood. This study describe the perceptions, knowledge, and practices of adults concerning indoor environmental pollution. Adults of 18 to 45 years of age were recruited in the department of Ille-et-Vilaine (Brittany-France) in 2019 through a stratified random draw in the waiting rooms of general practitioners (GPs) (n = 554) who completed a self-questionnaire. The 71% who had already heard of this type of pollution were older (p = 0.001), predominantly women (p = 0.007), not expecting a baby (p = 0.005), and had a higher knowledge score (p < 0.001). The average knowledge score was 6.6 ± 6.6 out of 11, which was higher for participants living in a couple and with a higher level of education (p < 0.001). Some practices were well implemented (>80% of participants) (aeration during renovation) whereas others were insufficiently practiced (<60% of participants) (paying attention to the composition of cosmetic products). Factors associated differed depending on the frequency of integration: living in a couple and having a child for well implemented practices and educational level, knowledge level, and perception for those under implemented. Knowledge must be improved to modify perceptions and certain practices, making sure not to increase social inequalities in health.

Risk of genotoxic damage in schoolchildren exposed to organochloride pesticides

This study identified and determined organochloride pesticide (OCs) concentrations in hair samples from children at two elementary schools: one exposed to fumigations in agricultural fields, the other unexposed. Three concentrations of OCs levels in the hair were compared (high, medium, low), and total nuclear abnormalities in buccal cells were determined: micronuclei (MNi), condensed chromatin, karyorrhexis, pyknosis, binucleate cells, karyolysis, lobed nuclei, and apoptosis. No significant differences were found for the presence of MNi between the schoolchildren from the exposed and unexposed schools, but the prevalence of OCs in both schools was over 50%, as well as the frequencies of MNi in the children were over 58%. Findings show a significant difference between the frequency of MNi in the total sample of schoolchildren (exposed school + unexposed school) in relation to the concentration of OCs detected in their hair. The children from exposed school that showed the higher concentrations of OCs in hair had higher levels of genotoxic damage in the buccal cells; compared against children with lower concentrations of OCs. The most frequent nuclear abnormalities in the exposed children were lobed nuclei (79.4%), binucleate cells (66.66%), apoptosis (65.07), and MNi (58.7%). We determined the prevalence ratio (PR) and prevalence odds ratio (POR) for the presence of MNi in buccal cells in relation to the OCs concentrations in the hair samples. Both ratios were high for MNi [PR 3.93, 95% confidence interval (CI) 1.97–7.84, p = 0.0003; and POR 7.97, 95% CI 2.62–24.28, p = 0.0003], indicating a 7.97 times greater risk that the exposed children will present > 0.2% of MNi when OCs concentrations exceed 0.447 μg/g. These indicators may be useful biomarkers of genotoxic damage in children exposed to persistent, highly-toxic compounds. Results suggest the potential risk to which those schoolchildren are exposed on a daily basis due to fumigations in nearby agricultural fields.

Impact of pesticide exposure in childhood

Pesticides represent a wide variety of chemicals presented as different formulations and concentrations and used in different settings: agriculture, animal sanitary bath, domestic use, and vector control. Lack of awareness, poor agricultural practices, and inappropriate disposal of containers will increase the exposure and risk of health effects during childhood. The concern about children's exposure to pesticides is based on their toxic properties and the special vulnerability to the exposure, which may occur in different stages, from the prenatal period to infancy. Pesticide related diseases may manifest during the infancy, adolescence, or adulthood. Children may be exposed by multiple routes of exposure, in different scenarios. In domestic settings, insecticides and rodenticides are usually stored within the reach of children, or may be transferred to non-original containers, leading to acute non intentional ingestion. Exploratory behavior increases the risk for exposure to pesticides present on the ground. Gardens and playgrounds may have pesticides residues. Children may be in contact with domestic animals that have been treated with pesticides. In rural settings, children can be exposed to pesticide residues in areas where they have been applied, or by contamination of work equipment and parents clothing. Families dedicated to rural activity have higher levels of exposure, through ingesting contaminated fruits, vegetables, milk, eggs, and water. Several studies confirmed pesticide exposure in children by biomonitoring. Higher levels of organophosphate metabolites have been reported in children compared to adult populations. Toxic effects of pesticides depend on their intrinsic toxic properties as well as on the dose, duration, and life period of exposure. Acute poisonings are related to high doses exposure, while chronic, subtle and delayed effects are often related to low levels/doses exposure. Epidemiologic, animal, and clinical studies suggest an association between chronic, low-level exposures and alterations in growth and development (particularly impaired neurobehavioral development), cancer and increased susceptibility to infections. New research presents evidence that some pesticides are a risk factor of a wide range of acute and chronic diseases. Better practices and public health policies are needed to prevent and protect children from pesticides exposure.

Agricultural crop density in the municipalities of France and incidence of childhood leukemia: An ecological study

BACKGROUND

Pesticide exposure is suspected to play a role in the etiology of childhood leukemia (AL). Various sources of exposure have been explored, but few studies have investigated the risk of childhood AL in relation to residential exposure to agricultural pesticides. Since around 50% of France is agricultural land, with marked pesticide use, France is a suitable location to investigate for an association. We aimed to analyze the association between the agricultural crop density in the municipalities of France and the incidence of childhood AL between 1990 and 2014.

METHODS

11,487 cases of AL diagnosed in children aged 0-14 years were registered by the French National Registry of Childhood Hematological Malignancies over 1990-2014. National agricultural census data for 1990, 2000 and 2010 were used to estimate the densities of the most common crops in France. The incidence of AL was estimated in the 35,512 municipalities, by age and gender, and 3 observation periods, and expressed as the standardized incidence ratio (SIR).

RESULTS

We observed a moderate log-linear association between viticulture density and the incidence of AL, with a 3% increase in SIR for a 10% increase in viticulture density (SIRR = 1.03; 95%CI [1.00-1.06]). The association remained for lymphoblastic AL but not for myeloid AL. The association was stable after stratification by geographic area, age and period, and after adjustment on UV radiation and a French deprivation index. No consistent association was observed for other crop types.

DISCUSSION

This nationwide study shows a moderate increase in incidence of childhood AL in municipalities where viticulture is common. Future individual studies are needed to know whether this observation is confirmed and related to particular use of pesticides.

Recent cancer incidence trends and short-term predictions in Golestan, Iran 2004-2025

BACKGROUND

We examine recent trends in the major cancers occurring in the Golestan province, a high-risk region for upper gastrointestinal cancers in Northern Iran, and provide short-term cancer predictions of the future cancer burden.

METHODS

New cancer cases diagnosed in Golestan 2004-2016 were obtained from the Golestan population-based cancer registry (GPCR) database, and age-standardized rates by cancer site, year and sex calculated per 100,000 person-years. Using IARC's DepPred package we fitted time-linear age-period models to the available GPCR data to predict the cancer incidence burden in the year 2025. We calculated the contribution of demographic changes versus changes in risk to the overall changes in incidence from 2016 to 2025.

RESULTS

The number of new cancer cases (excluding non-melanoma skin cancers) in 2025 is predicted to increase by 61.3% from 2678 cases in 2016 to 4319 cases. While a 17.6% reduction in the number of esophageal cancer cases is predicted by 2025, the number of new cases for each of the remaining major cancers is predicted to increase over the next decade, including cancers of the stomach (a 36.1% increase from 2016 to 2025), colorectum (56.2%), lung (67.8%), female breast (93.2%), prostate (101.8%) and leukemia (96.1%). The changes in the population structure and risk contributed 37.8% and 23.5% respectively, to the overall increase in incidence.

CONCLUSION

Other than for the major upper gastrointestinal cancer types, the incidence rates of common cancers observed in the province are on the rise, reinforcing the need for continuous surveillance, as well as the design and implementation of effective cancer control programs.

Occupational exposure to pesticides and associated health effects among greenhouse farm workers

The number and production capacities of greenhouse farms have been increased across the globe, driven by an effort for addressing food security problems related to the rapid population growth and the effects of climate change. As a result, there was a large increase in the number of greenhouse farm workers who are typically involved in chemical preparations and pesticide sprayings, crop harvesting, and greenhouse maintenance activities. Considering the enclosed architecture of the greenhouse farm design and the frequent application of pesticides, the objective of this review was to characterize pesticide exposure levels and resultant health effects among greenhouse farm workers. While most health assessment studies were mainly based on self-reported symptoms, this review showed limited epidemiological and clinical studies on the assessment of the health effects of pesticide exposure on greenhouse workers' health. Reproductive disorders, respiratory symptoms, neurological symptoms, and skin irritations were the most reported health effects among greenhouse farm workers. Additionally, there were limited studies on respirable pesticide-borne fine and ultrafine particulate matters in greenhouse farms. Ventilation systems and indoor environmental conditions of greenhouse farms were not designed according to specifications of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). Among recommendations provided, long-term exposure assessments of pesticide effects on children born by greenhouse farm workers should be considered in future research. Also, compliance with ASHRAE indoor ventilation and environmental standards will be very important in reducing pesticide exposure and health effects among greenhouse farm workers.

Epidemiological studies of natural sources of radiation and childhood cancer: current challenges and future perspectives

The empirical estimation of cancer risks in children associated with low-dose ionising radiation (<100 mSv) remains a challenge. The main reason is that the required combination of large sample sizes with accurate and comprehensive exposure assessment is difficult to achieve. An international scientific workshop, 'Childhood cancer and background radiation', organised by the Institute of Social and Preventive Medicine of the University of Bern, brought together researchers in this field to evaluate how epidemiological studies of background radiation and childhood cancer can best improve our understanding of the effects of low-dose ionising radiation. This review summarises and evaluates the findings of these studies with regard to their methodological differences, identifies key limitations and challenges, and proposes ways to move forward. Large childhood cancer registries, such as those in Great Britain, France and Germany, now permit the conducting of studies that should have sufficient statistical power to detect the effects predicted by standard risk models. Nevertheless, larger studies or pooled studies will be needed to investigate disease subgroups. The main challenge is to accurately assess children's individual exposure to radiation from natural sources and from other sources, as well as potentially confounding non-radiation exposures, in such large study populations. For this, the study groups should learn from each other to improve exposure estimation and develop new ways to validate exposure models with personal dosimetry.

Benzyl butyl phthalate (BBP) triggers the malignancy of acute myeloid leukemia cells via upregulation of PDK4

Acute Myeloid Leukemia (AML) is a cancer of hematopoietic stem cells with a rapid progression. Recent studies indicated that endocrine disruptor chemicals (EDCs) are potential risk factors for AML progression. Our present data showed that an industrial endocrine disrupting chemical, Benzyl butyl phthalate (BBP), can promote the proliferation of AML cells and decrease their sensitivity to daunorubicin (DNR) and cytarabine (Ara-C) treatments. Further, BBP can increase the glucose consumption, lactate generation, and ATP levels of AML cells. Among the measured glycolysis-related genes, BBP can increase the expression of pyruvate dehydrogenase lipoamide kinase isozyme 4 (PDK4), a mitochondrial protein that regulates the tricarboxylic acid cycle (TCA) cycle. The inhibitor of PDK4 or its specific siRNA can attenuate BBP-induced cell proliferation and ATP generation, which suggested the essential roles of PDK4 in BBP-induced glycolysis and proliferation. Further, BBP can increase the mRNA stability of PDK4, while had no effect on its transcription and protein stability. miR-15b-5p can bind with the 3'UTR of PDK4 to decrease its mRNA stability, while BBP can decrease the expression of miR-15b-5p in AML cells. Collectively, our data showed that BBP can trigger the malignancy of AML cells via regulation of miR-15b-5p/PDK4 signals.

Precision medicine and health disparities: The case of pediatric acute lymphoblastic leukemia

BACKGROUND

Precision medicine has uncertain potential to address population health disparities.

PURPOSE

Case study of disparities in pediatric acute lymphoblastic leukemia (ALL).

METHOD

Literature-based evaluation of ALL in African American (AA) and European American (EA) children.

FINDINGS

AA children have a lower incidence of ALL than EA children, experience higher relapse rates, and are more likely to be diagnosed with poor prognostic indicators. Environmental risk exposures for ALL have small effect sizes; data are insufficient to determine their contribution to differences in incidence and prognosis. Differences in prevalence of gene variants associated with treatment response contribute to higher relapse rates in AA children. However, higher relapse rates were not seen in a care setting that eliminated out of pocket costs, used risk-directed therapy, and included rigorous case management.

DISCUSSION

Unequal access to effective treatment contributes to ALL disparities. Precision medicine can help to define effective treatment for diverse patient populations.