05
Aug
Pesticide Pollution from Chemical-Intensive Farming Diminishes Some Benefits of Organic Production
(Beyond Pesticides, August 5, 2025) A biomonitoring study in Environmental Geochemistry and Health, focused on small-scale farms in Pahang, Malaysia, analyzes levels of essential and toxic elements in hair and nail samples from chemical-intensive and organic farmers. While the results reveal elements that correlate with specific farming practices, common elements to both chemical-intensive and organic farming highlight the role of pesticide drift in off-target contamination, diminishing some of the benefits of organic agriculture. The persistent and pervasive nature of many pesticide products results in exposure patterns, in addition to direct occupational exposure on chemical-intensive conventional farms, that trespass onto organically managed land and threaten health and the environment—raising policy and practice issues needed to safeguard the public.
Cameron Highlands in Malaysia is a region known for intensive pesticide use as well as for its vegetable and flower farming, where both conventional and organic agriculture exist in close proximity. “Despite different agricultural approaches, both groups remain at risk of environmental exposure due to long-term pesticide application in the region,†the authors write. They continue, “While organic farming practices may reduce direct exposure to synthetic agrochemicals, the risk of cross-contamination from surrounding conventional farms remains a concern due to environmental dispersion through soil, water, and air.â€
Farmers, farmworkers, and their families across the globe face disproportionate risks from pesticide exposure. (See more here and here.) As previously shared in Beyond Pesticides’ Daily News Disproportionate Pesticide Hazards to Farmworkers and People of Color Documented. . .Again, there is a long history of documented hazards and government failure to protect farmworkers from pesticide use in agriculture. Farmworkers, some of whom can be pesticide applicators, often live very near the fields and orchards where pesticides are applied. These chemicals are prone to drift and can volatilize (evaporate/disperse), causing nontarget exposure to humans, wildlife, and the environment. (See additional Daily News coverage on farmworkers here.)
Within the current study, the researchers note that an increasing number of farmers in the Cameron Highlands are responding to the growing concerns of adverse health impacts tied to prolonged exposure to the harmful chemicals used in conventional agriculture, with many transitioning to organic farming. “However, despite these efforts to reduce synthetic agrochemical exposure, organic farmers remain susceptible to environmental contamination from neighbouring conventional farms,†the authors write.
The use of petrochemical pesticides and synthetic fertilizers in conventional agriculture represents not only a direct occupational exposure route to trace elements for those who apply the chemicals, but it is a source of contamination to those in the surrounding environment. These elements are bioaccumulative, with both acute and chronic health effects.
In the study, hair and nail samples are analyzed for essential metals such as sodium (Na), magnesium (Mg), iron (Fe), zinc (Zn), which “are crucial for various physiological functions, including enzymatic reactions, cellular metabolism, and immune regulation, but must remain within optimal ranges to prevent deficiencies or toxicity,†the researchers state. (See research here.)
They continue: “Conversely, toxic metals such as chromium (Cr), arsenic (As), cadmium (Cd), mercury (Hg), lead (Pb) pose significant health risks due to their ability to bioaccumulate and cause neurotoxicity, carcinogenicity, and metabolic disturbances. These elements exhibit distinct toxicokinetic [how a substance moves through the body and relates to its toxic effects] properties; some disrupt essential biochemical pathways, while others contribute to cumulative toxicity with prolonged exposure.†(See studies here and here.)
In using hair and nails as biological samples, this reflects longer-term, cumulative exposure for trace elements unlike blood or urine that only accounts for recent exposure. As the study authors point out, “Hair sequesters trace elements over weeks, while nails, due to their slower growth rate, reflect exposure over several months.â€
The participants in the study include vegetable farmers who have lived and worked in the study area for at least 12 months and are between 18 and 60 years of age. The organic farmers, 15 of the 62 total farmers, were also required to have experience in organic agriculture, with no use of synthetic agrochemicals for at least the past year, while the conventional farmers, the remaining 47 participants, reported routine use of synthetic pesticides and fertilizers.
The results reveal significant differences in trace element concentrations between the farmers of conventional and organic farms. “Overall, conventional farmers exhibited higher median concentrations of most toxic elements compared to organic farmers,†the authors state. Specifically, in the hair samples chromium levels are significantly higher in conventional farmers, with elevated mercury levels noted as well. Of the essential elements, iron and sodium were both slightly higher in organic farmers, which can be attributed to variations in soil management and fertilizer use. These variations between the two groups suggest a strong link between agrochemical uses and exposure.
Within the nail samples, zinc levels are significantly higher in conventional farmers compared to organic farmers, which shows a link between conventional farming practices and exposure to this element in excess from zinc-enriched products. “For conventional farmers, continuous exposure to zinc through fertilizers, pesticides, and soil contact over time may lead to its accumulation in the body, which is reflected in higher zinc concentrations in nail samples,†the authors explain. Of the toxic elements, the convention farmers also show higher mean concentrations of chromium, manganese, lead, and mercury in their nails as compared to organic farmers.
“However, the detection of certain trace elements in both groups highlights the impact of shared environmental contamination, driven by historical and ongoing pesticide and fertilizer use in the highlands,†the researchers state. They continue: “[T]oxic elements such as arsenic (As), cadmium (Cd), and lead (Pb) did not differ significantly between the two groups, although median levels were slightly higher among conventional farmers… [B]oth groups showed overlapping exposure profiles, potentially due to shared environmental background contamination in this pesticide-intensive highland region.â€
The long-standing use of pesticides and fertilizers within the region plays a critical role in exposure to contaminants for all farmers and residents. “Despite having different farming methods, agrochemicals’ historical and ongoing use has contaminated soils and caused environmental interactions that have an impact on both conventional and organic farmers,†the authors conclude.
They continue: “This shared environmental exposure can mask the potential impact of farming practices, leading to similar levels of these toxic elements in both groups… The potential cross-contamination raises concerns about the exposure risk for all farmers in the region and emphasizes the need for improved safety measures, environmental monitoring, and sustainable farming practices.â€
The shared contamination in the environment through farmland soils, atmospheric dispersion, and water sources highlights the urgent need to fully transition agriculture to sustainable methods. Previous research suggests “that pesticide drift, contaminated irrigation systems, and soil leaching facilitate the unintended transfer of synthetic agrochemicals and trace elements, undermining the benefits of organic farming.†(See studies here and here.)
Beyond Pesticides has extensively covered the multitude of health and environmental benefits of organic land management practices. These benefits are not only for farmers and farmworkers, but for all consumers, wildlife, and the ecosystems in which they depend upon. Regenerative organic agriculture provides soil health benefits (see Daily News here), as well as mitigates the current crises of climate change and biodiversity (see here and here). These methods result in both more nutritious food and higher crop yields, as shown in scientific literature covered in the Daily News Sixteen Year Field Trial Shows Organic Corn Outcompetes Chemical-Intensive Fields in Kenya.
Additional research, highlighted in Study Demonstrates Health Benefits of Organic Diet Over That Consumed with Toxic Pesticides, shows how adopting a fully organic diet can reduce pesticide levels in urine within just two weeks “by an average of 98.6%†and facilitate faster DNA damage repair relative to a diet of food grown with chemical-intensive practices. These benefits, however, as documented in the current study, can be overshadowed by the widespread contamination that occurs with chemical-intensive methods.
The findings in this study reinforce the urgent need for a full transition to organic in both agriculture and land management to protect the health of all individuals. >> Tell Congress To Restore Funding that Protects the Health of Farmers, Farmworkers, and Families.
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All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source:
How, V. et al. (2025) Evaluation of trace element in the hair and nail samples of conventional and organic farmers in pesticide-treated highland villages, Environmental Geochemistry and Health. Available at: https://link.springer.com/article/10.1007/s10653-025-02635-1.
