Biomonitoring and risk assessment of organochlorine pesticides among Saudi adults

Current exposure to environmental pollutants in the general adult population of Kinshasa, Democratic Republic of Congo (DRC): A cross-sectional study

BACKGROUND

Environmental pollution is a serious public health problem because of its adverse effects on both human health and biodiversity. In Western countries, many human biomonitoring (HBM) studies are conducted to assess population exposure to pollutants. In contrast, the number of HBM studies in Africa is very low.

OBJECTIVE

To measure contamination by arsenic, lead, 4,4'-dichlorodiphenyldichloroethylene (4,4'-DDE) and polychlorobiphenyls (PCBs) in the adult population of Kinshasa and to identify the susceptible population.

METHODS

In the present work, we measured the contamination by arsenic in urine and lead in blood and by 4,4'-DDE and polychlorobiphenyls (PCBs) in serum in samples collected from 151 volunteers recruited in Kinshasa, the capital of the Democratic Republic of Congo (DRC).

RESULTS

The PCBs 180, -153 and -138 were detected in most samples with median concentrations of 0.04, 0.05 and 0.04 ng/ml, respectively. The median concentration of 4,4'-DDE was 0.83 ng/ml and 12.7% of our population showed contamination above the threshold of 3.675 ng/ml, which is associated with a significantly higher risk of cancer. Arsenic concentrations were also high (median: 48.1 μg/L in urine). Finally, exposure to lead is problematic: the median blood concentration was 54.9 μg/L, which is above the thresholds proposed by the WHO and the US CDC (50 μg/L and 35 μg/L respectively) to initiate clinical intervention, and 12.6% of the population had a lead level above 100 μg/L, which is associated with several health outcomes.

CONCLUSIONS

Our results highlight the need for further HBM studies in Africa and should encourage the authorities of the DRC to implement laws and regulations to reduce pollution and population exposure.

Cross-sectional study on urinary metal concentrations in young adult residents of Emirate of Sharjah, United Arab Emirates

BACKGROUND

Human biomonitoring is crucial for regulatory toxicology, yet data on biomarker concentrations in the UAE are lacking. This study addresses this gap by analyzing urinary concentrations of 16 metals in UAE young adults, assessing correlations with personal characteristics, dietary patterns, and lifestyle habits.

METHODS

A cross-sectional pilot study was conducted among 144 randomly selected young adults (71 males and 73 females) from Sharjah, UAE, between January and March 2023. Participants provided urine samples, which were analyzed for 16 heavy metals using ICP-OES, and completed detailed questionnaires covering sociodemographic factors, lifestyle, and dietary habits. Descriptive statistics were used to summarize participant characteristics, and linear regression analysis was applied to explore associations between metal concentrations and factors such as gender, dietary habits, and exposure to environmental risks. Non-parametric tests, including the Mann-Whitney test, were used to assess differences by gender. Statistical significance was set at p < 0.05. Ethical approval was obtained, and informed consent was secured before participation.

RESULTS

Significant findings include dietary influences on metal exposure, with rice consumption linked to higher metal concentrations. Sex differences were significant, with females showing elevated levels of arsenic, lead, and cadmium. Lifestyle factors, such as smoking and incense use, were correlated with increased barium and boron levels.

CONCLUSION

This study highlights the significant role of dietary habits, especially the consumption of rice, in metal exposure among young adults in Sharjah. The findings highlight the urgent need for comprehensive human biomonitoring to understand environmental exposures and reform public health policies. The gender-specific differences in metal distribution suggest the necessity for targeted public health strategies. The study, however, is limited by its cross-sectional nature and the focus on a specific geographic area, warranting further research for broader generalizability. Future investigations, particularly on the impact of incense exposure on metal levels, are essential for developing comprehensive health interventions and preventive strategies in the UAE.

Human biomonitoring of environmental contaminants in Gulf Countries - current status and future directions

BACKGROUND

This systematic review aimed to evaluate the status of Human Biomonitoring (HBM) in the Gulf Cooperation Council (GCC) region and provide recommendations for future research, considering the increased environmental contaminants that pose a threat to human health in this rapidly industrializing area.

METHODS

A thorough search was performed in PubMed and Web of Science databases up to February 2023 to identify biomonitoring studies on human exposure and levels in the GCC region. Two independent reviewers assessed study eligibility, conducted data extraction and risk of bias assessment. The NIH Quality Assessment Tools and PRISMA guidelines were utilized for quality evaluation and reporting of results.

RESULTS

A total of 38 eligible articles were included in this systematic review out of 662 articles screened. The majority of the publications were from Saudi Arabia (n = 24) and Kuwait (n = 10), while limited representation was found from Qatar (n = 3) and the UAE (n = 1). No articles were identified from Oman and Bahrain. The studies focused on metals, organohalogen compounds, pesticides, polycyclic aromatic hydrocarbons, and phthalates. The findings revealed elevated levels of metals and established correlations between metal exposure and adverse health effects, including infant neurodevelopmental issues, vitamin D deficiency, and oxidative stress. The presence of organohalogen compounds and pesticides was prevalent in the GCC region, with significant associations between exposure to these compounds and negative health outcomes. Notably, high levels of perchlorate were observed in the Kuwaiti population, and a study from Saudi Arabia found an association between per- and polyfluorinated substances and increased odds of osteoporosis.

CONCLUSIONS

This review emphasizes the need to address environmental health challenges in the GCC region through improved HBM research methods and strategies. Implementing biomonitoring programs, conducting cohort studies, investing in tools and expertise, promoting collaboration, and engaging the community are crucial for reliable HBM data in the GCC.

Evaluating the Level of Pesticides in the Blood of Small-Scale Farmers and Its Associated Risk Factors in Western Ethiopia

BACKGROUND

The presence of agricultural pesticide residue can cause adverse health effects.The main objective of this study was to evaluate the level of pesticides in the blood of small-scale farmers (SSFs) and associated risk factors in western Ethiopia.

METHODS

Across sectional study was conducted in June 2020 using 240 blood samples, 140 from the exposed small-scale farmers (ESSFs) and 100 from non-exposed small-scale farmers (NESSFs). The blood sample analysis was mad for 5 organochlorines (OCs) and 3 synthetic pyrethroids (SPs) pesticides by gas-liquid chromatography with an electron capture detector (GC-ECD) methods. Extraction, and clean up of the samples were made by using standard analytical methods. To define the relationships between the outcomes and explanatory variables, logistic regression models were used.

RESULTS

The results shows that p,p'-DDT, heptachlor and deltamethrin were the most frequently detected pesticides with 96.4%, 95%, and 100% in both ESSFs and NESSFs, respectively. The ESSFs blood samples have shown the highest mean concentrations of permethrin and p,p'-DDT(1.26 ± 0.15) and (0.28 ± 0.4) mgL^-1, respectively. SSFs under the age of 40 were 21% less likely to be exposed to permethrin than those above the age of 40 (Adjusted Odd Ratio, AOR, 0.21; 95% CI: 0.1-0.44). Male SSFs were 17 times more likely to be exposed to heptachlor than females (AOR, 17.36; 95%CI: 7.34-41.09) and farmers with no formal education were 18 times more likely to be exposed to deltamethrin than those with primary schools and beyond (AOR, 18.1; 95 %CI: 4.53-72.06). Furthermore, SSFs that did not use PPE appropriately were 3.6 and 6.21 times more likely to be exposed to cypermethrin (AOR, 3.6; 95%CI: 1.94-6.54) and p,p'-DDE(AOR, 6.21; 95%CI: 3.38-11.41) blood levels than those who did, respectively. SSFs that perform different activities like eating and drinking (11%), chewing (10%), and diverse activities (8%) were more likely to be exposed to p,p'-DDT than those farmers who didn't use pesticides.

CONCLUSIONS

This study identified a high concentration p,p'-DDE, p,p'-DDT, heptachlor, cypermethrin, permethrin, and deltamethrin in the blood of small scale farmers. The older age, less education, and farmers with inappropriate PPE use are more likely exposed to pesticides.

Validation of exposure indexes to pesticides through the analysis of exposure and effect biomarkers in ground pesticide applicators from Argentina

The characterization of the population exposed to pesticides and the use of effective biomarkers to evaluate potential health effects are determinant to identify vulnerable groups, understanding the causality of diverse pathologies and propose prevention policies. This is particularly important in countries where intensive agricultural practices had an explosive expansion in last decades. The aim of this study was assessing the usefulness of two exposure indexes questionnaire-based: Intensity Level of the pesticide Exposure (ILE) and Cumulative Exposure Index (CEI) and their scales, in terrestrial applicators of pesticide from the Province of Córdoba (Argentina). The analysis was performed contrasting ILE and CEI results with perceived symptomatology, in addition to effect and exposure biomarkers. A cross-sectional study was designed to compare pesticides body burdens and effect biomarkers between subjects occupationally (OE) and non-occupationally exposed (NOE) to pesticides. Prevalence of perceived symptomatology and genotoxicity damage was higher in the OE group. The exposure condition was the only variable explaining these differences. Significant associations were found between CEI and neurologic symptomatology (p < 0.05) and between ILE and plasmatic cholinesterase (p < 0.1). However, residues of HCB, β-HCH, α-endosulfan, pp'DDE, endrin, β-endosulfan, pp'DDT, endosulfan sulfate and mirex were found in blood samples from both groups. To our knowledge, this is the first report on pesticides body burdens in occupational exposure settings in Argentina. So far, our current results indicate that the occupational condition affects the health of the workers. Significant associations found between symptomatology and biomarkers with scales of CEI and ILE suggest their usefulness to verify different levels of exposure. Further research is necessary to propose these indexes as an affordable tool for occupational health surveillance in areas with difficult access to health care centres.