Childhood leukemia mortality and farming exposure in South Korea: A national population-based birth cohort study

Follicular DNA Damage and Pesticide Exposure Among Latinx Children in Rural and Urban Communities

The intersectional risks of children in United States immigrant communities include environmental exposures. Pesticide exposures and their biological outcomes are not well characterized in this population group. We assessed pesticide exposure and related these exposures to DNA double-strand breaks (DSBs) in Latinx children from rural, farmworker families (FW; N = 30) and from urban, non-farmworker families (NFW; N = 15) living in North Carolina. DSBs were quantified in hair follicular cells by immunostaining of 53BP1, and exposure to 72 pesticides and pesticide degradation products were determined using silicone wristbands. Cholinesterase activity was measured in blood samples. DSB frequencies were higher in FW compared to NFW children. Seasonal effects were detected in the FW group, with highest DNA damage levels in April-June and lowest levels in October-November. Acetylcholinesterase depression had the same seasonality and correlated with follicular DNA damage. Organophosphate pesticides were more frequently detected in FW than in NFW children. Participants with organophosphate detections had increased follicular DNA damage compared to participants without organophosphate detection. Follicular DNA damage did not correlate with organochlorine or pyrethroid detections and was not associated with the total number of pesticides detected in the wristbands. These results point to rural disparities in pesticide exposures and their outcomes in children from vulnerable immigrant communities. They suggest that among the different classes of pesticides, organophosphates have the strongest genotoxic effects. Assessing pesticide exposures and their consequences at the individual level is key to environmental surveillance programs. To this end, the minimally invasive combined approach used here is particularly well suited for children.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12403-023-00609-1.

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.

Pesticide exposure and cognitive decline in a rural South Korean population

We aimed to investigate the relationship between pesticide exposure and cognitive decline in a rural South Korean population. From July 2015 to December 2017, 200 randomly selected Korean Farmers Cohort study participants were recruited and of these, 169 participants were analyzed. Pesticide exposure was investigated using a standardized questionnaire, and the Korean-Montreal Cognitive Assessment (K-MoCA) was conducted. Cognitive decline was more frequent among those directly exposed to pesticides (P = 0.057). Pesticide exposure and cognitive decline were positively correlated in the group with direct exposure versus no exposure (crude odds ratio [OR], 2.66; 95% confidence interval [CI], 1.17–6.04); this relationship was insignificant after adjustment (adjusted OR, 1.50; 95% CI, 0.57–3.92). There was a significant difference in the K-MoCA scores for each group based on pesticide exposure (P = 0.003). When we stratified by age, differences in the K-MoCA scores depending on the degree of pesticide exposure in the those aged 60 to 69 years were identified. Overall, there was a tendency towards an association between pesticide exposure and cognitive decline in rural Korean adult farmers. In our study, chronic pesticide exposure tended to have a greater impact in certain age group (60–69 years) than in those under 60 and over 70.

Differences in incidence and survival to childhood cancer between rural and urban areas in Castilla y León, Spain (2003-2014): A Strobe-compliant study

The aim of this study is to describe childhood cancer incidence and survival in Castilla y León (Spain) for the period 2003 to 2014 and to explore differences between rural and urban areas.We made a cohort study in the childhood population of our region for the period of years referred before. Age-adjusted incidence rates to the world standard population (ASRw) were calculated by direct method, and their comparisons were made using incidence rate rations. Survival proportions were calculated by Kaplan-Meier method and their comparisons with log-rank test. The median childhood population less than 15 years old was 296,776 children. A total of 615 cases were recorded from the population-based Childhood Cancer Registry, including all malignant and benign tumors of the central nervous system.Age-standardized incidence rates for all cancers were 176.6 per million. Leukemia incidence rates were highest in rural areas (51.08/million) than in urban areas (33.65/million; P = .018), and by age groups; these differences only remained at age 0 to 4 years with higher rural leukemia incidence (67.13/million) than in urban areas (39.32/million; P = .05). There were no statistically significant differences between rural and urban areas for lymphomas, central nervous system, and all other malignant solid tumors grouped. The 5-year overall survival rate for all patients was 84%, similar to other developed countries, with greater survival in rural areas (88%) compared with urban areas (80%; P = .033). The analysis by tumor groups showed a greater survival rate in rural areas for all the groups, although these differences only reached statistical significance in the group of leukemias, with a survival rate of 90% for rural areas compared with 76% for urban areas (P = .01). Analyzing survival rate by age groups in leukemias only significant survival differences at 10 to 14 years were encountered.We found a higher incidence of leukemia in girls, mainly in rural areas, and also a better survival rate in children diagnosed with leukemia belonging to this population area. Future studies that analyze these facts in similar populations can help us clarify what genetic, epigenetic and environmental factors influence our population and are responsible for these findings.

Livestock and poultry density and childhood cancer incidence in nine states in the USA

BACKGROUND

Parental occupational and childhood exposures to farm animals have been positively associated with childhood brain tumors, whereas associations with childhood leukemia are equivocal. The developing immune system may be influenced by allergen, virus, or other exposures from animal sources, which may contribute to childhood cancer incidence.

METHODS

Incident cancers (acute lymphoblastic leukemia [ALL], acute myeloid leukemia [AML], central nervous system [CNS], peripheral nervous system [PNS]) for children aged 0-4 diagnosed between 2003 and 2008 were obtained from nine National Cancer Institute Surveillance, Epidemiology and End Results (SEER) registries and were linked to U.S. Census of Agriculture data from 2002 and 2007 by county of diagnosis. Animal densities (animal units [AU]/km²; one animal unit is 1000 pounds of animal weight) were estimated for hogs, cattle, chickens (layers and broilers, separately), equine (horses, ponies, mules, burros, donkeys), goats, sheep, turkeys, and total animals. Animal density was examined in models as both continuous (AU per km²) and categorical variables (quartiles). Animal operation densities (per km²) by size of operation (cattle, hogs, chickens, sheep) were modeled continuously. Rate ratios and 95% confidence intervals were estimated using Poisson regression.

RESULTS

We found positive associations between AML and broiler chicken densities (RR_{per 10AU/km}² = 1.14, 95% CI = 1.02-1.26). ALL rates increased with densities of hog operations (RRper operation/100km² = 1.06, 95% CI = 1.02-1.11). PNS cancer rates were inversely associated with layer chicken density (RR_{per log of AU/km}² = 0.94, 95% CI = 0.89-0.99). No association was found between any cancer type and densities of cattle, equine, or goats.

CONCLUSIONS

Although limited by the ecologic study design, some of our findings are novel and should be examined in epidemiological studies with individual level data.

Personal samplers of bioavailable pesticides integrated with a hair follicle assay of DNA damage to assess environmental exposures and their associated risks in children

Agriculture in the United States employs youth ages ten and older in work environments with high pesticide levels. Younger children in rural areas may also be affected by indirect pesticide exposures. The long-term effects of pesticides on health and development are difficult to assess and poorly understood. Yet, epidemiologic studies suggest associations with cancer as well as cognitive deficits. We report a practical and cost-effective approach to assess environmental pesticide exposures and their biological consequences in children. Our approach combines silicone wristband personal samplers and DNA damage quantification from hair follicles, and was tested as part of a community-based participatory research (CBPR) project involving ten Latino children from farmworker households in North Carolina. Our study documents high acceptance among Latino children and their caregivers of these noninvasive sampling methods. The personal samplers detected organophosphates, organochlorines, and pyrethroids in the majority of the participants (70%, 90%, 80%, respectively). Pesticides were detected in all participant samplers, with an average of 6.2±2.4 detections/participant sampler. DNA damage in epithelial cells from the sheath and bulb of plucked hairs follicles was quantified by immunostaining 53BP1-labled DNA repair foci. This method is sensitive, as shown by dose response analyses to γ radiations where the lowest dose tested (0.1Gy) led to significant increased 53BP1 foci density. Immunolabeling of DNA repair foci has significant advantages over the comet assay in that specific regions of the follicles can be analyzed. In this cohort of child participants, significant association was found between the number of pesticide detections and DNA damage in the papilla region of the hairs. We anticipate that this monitoring approach of bioavailable pesticides and genotoxicity will enhance our knowledge of the biological effects of pesticides to guide education programs and safety policies.

Pesticide knowledge and practice among horticultural workers in the Lâm Đồng region, Vietnam: A case study of chrysanthemum and strawberries

BACKGROUND

In Vietnam, large amounts of pesticides are being used in agriculture. Next to benefits for agriculture, pesticides impose a huge threat to the environment when they are used in the wrong way. The objective of this work was to determine the level of knowledge and awareness of the smallholder farmers towards the use of pesticides in Vietnam, Dà Lat region. Based on the collected data, an occupational and environmental risk assessment was performed.

RESULTS

The results indicate that the majority of the pesticide operators in the strawberry and chrysanthemum crops have a rather high education. Pesticide knowledge, on the other hand, is usually gained through experience with pests and diseases. Only 30% of the farmers consulted a pesticide specialist or government stewardship for information on (new) pesticide products. Pesticide usage is rather high with application frequencies up to once every three days during the wet season. Pesticide packages are stored to be incinerated (51%) or to be thrown away with the garbage/taken to the landfill (37%). Only a small percentage disposes the packages into the local river (2%). The use of personal protection equipment is well established. Occupational risk assessment showed that the re-entry worker is exposed to a high risk.

CONCLUSION

While a general awareness of the hazard of pesticides to human health and the environment is present, practical implementation of this awareness, however, is still limited in strawberry and chrysanthemum crop. The environmental risk evaluation indicated plant protection products of which the use should be limited.