17
Jun
Past Use of Lead Arsenate Pesticides Continue to Contaminate Residential Areas 70 Years Later
(Beyond Pesticides, June 17, 2021) Lead arsenate pesticides continue to contaminate Central Washington residential areas that were once tree fruit orchards. Although these toxic legacy pesticides have not been in use for almost 70 years, the Washington State Department of Ecology report finds lead and arsenic soil concentrations above the Washington State cleanup levels. It is well-known that traces of legacy (past-use) pesticides, like organochlorines, remain in the environment for decades—possibly centuries, post-final application. However, these chemicals have profound adverse impacts on human health, with links to cancer, reproductive and endocrine (hormone) disruption, and birth/developmental abnormalities. Current-use pesticides also contaminate the ecosystem via drift, runoff, and leaching. Therefore the impact of both current and past use of pesticides on human, animal, and environmental health, especially in combination, is critical to any safety analysis.
The researchers note, “Historical application of lead arsenate (LA) pesticides on tree fruit orchards has resulted in the accumulation of lead and arsenic in shallow soil at concentrations above Washington State cleanup levels. These are levels that may be harmful to human health when properties are used for activities other than agricultural or industrial land uses. This report outlines a recommended approach for managing and mitigating LA pesticide soil contamination, as well as educating impacted people and communities about the issue.”
The Washington State Department of Ecology examined lead arsenate pesticide contamination in areas of Central Washington from historical tree fruit orchard practices. There are increasing concerns over health risks to residents living in areas of past pesticide use, especially for those unaware of possible contamination. Hence, the department established the Legacy Pesticide Working Group (LPWG) in 2019 to include stakeholders throughout Central Washington state “to address the complex issues surrounding lead and arsenic contamination on former orchard lands.”
For a year, the LPWG identified residential and commercial areas that were once tree fruit orchards. The group devised recommendations to help landowners, land developers, and communities combat contamination using the Washington State Model Toxics Control Act (MTCA) as a guide. The final recommendations include the following objectives:
- “Creating a process for evaluation of all properties.
- Notifying buyers and current homeowners concerning the specifics of LA pesticide contamination on their properties.
- Identifying actions that meet Ecology’s cleanup regulations.
- Creating a broad-based strategy for educating the public about managing the risk from [lead arsenate] pesticide contamination.”
The report finds approximately 115,000 acres of Central Washington has possible lead arsenate contamination from historical orchards, including existing and developing residential (i.e., single-family homes, apartment buildings) and commercial (i.e., malls, schools, parks) areas. From this data, the LPWG set up a “Dirty Alert” map highlighting historic orchards and possible lead arsenate contamination. Property owners can use the map to assess whether they reside in an area of contamination based on previous orchard locations.
The issue of environmental pesticide contamination is not a new phenomenon, especially for legacy pesticides. Pesticides are pervasive in all ecosystems, soils, water (solid and liquid), and air, frequently at levels exceeding U.S. Environmental Protection Agency (EPA) standards. Many legacy pesticides are on the Stockholm Convention annex lists (i.e., organochlorine compounds) and are no longer manufactured or utilized. However, 90 percent of Americans still have at least one pesticide biomarker (includes parent compound and breakdown products) in their body, including legacy compounds. The presence of pesticides in the body has implications for human health, especially during vulnerable life stages like childhood, puberty, pregnancy, and old age. Scientific literature demonstrates pesticides’ long history of severe adverse human health effects (i.e., endocrine disruption, cancer, reproductive/birth abnormalities, neurotoxicity) and effects on wildlife and biodiversity. Therefore, it is essential to address pesticide contamination using proper prevention practices, risk assessments, and clean-up methods to safeguard human, animal, and ecosystem health and services.
The study demonstrates most of the contamination in Central Washington is in the soil that can experience biological changes in the presence of synthetic chemical pollutants like pesticides. Past misconceptions assuming stable, banned chemicals like legacy pesticides would bind to soil and remain immobile are worrisome. However, studies find some current-use pesticides can induce changes in soil properties that re-release soil-bound, legacy chemicals into the ecosystem, contributing to contamination. A 2020 study finds glyphosate use stimulates soil erosion responsible for soil-based chemical emergence. Continuous pesticide use leaves the dirt bare and more susceptible to decay from lack of organic material, altering the storage compartments of soil sediments from pesticide sinks to sources. Furthermore, soil pesticide contamination impacts organisms, including beneficial insects and microbes that provide essential ecosystem services by aerating the soil, cycling nutrients, and increasing microbial activity.
This report is a valuable tool that serves as a model for pesticide contamination evaluation and recommendations globally. Although lead and arsenic are naturally occurring, these chemicals impact the endocrine system, kidneys, liver, heart, and brain. Exposure can prompt ailments like diabetes, reproductive dysfunction, and various cancers. Similar to current-use pesticides, the severity of poisoning depends upon the amount of chemical exposure, the length of exposure, and pre-established sensitivity to chemical exposure. Not only do reports like these protect future human health, but also human well-being. The current housing crisis demonstrates the need to transform idle landscapes into residential areas for housing development. However, similar to Central Washington, much of this idle land includes abandoned or barren agricultural pasture containing pesticide contamination from past use. In addition to agricultural land, the conversion of golf courses—known for using copious amounts of pesticides—into housing also poses similar health and environmental exposure risks. The researchers suggest decontaminating existing and developing residential areas, requiring property owners to investigate and clean up toxicants from land.
The researchers conclude, “The current confusion about the LA pesticide contamination issue has created a demand for significant education and outreach efforts geared toward reaching a wide variety of stakeholders. Areas of concern include ensuring all who may be affected (e.g., residents, local governments, developers) are aware of the issue; understanding who may be liable for historic LA pesticide contamination and required cleanup activities; creating consistent messaging and guidance related to compliance with MTCA; and making sure updated, accurate data is used to create easy to find mapping resources identifying areas that may be affected by historic LA pesticide applications.”
Legacy pesticide poisoning in the environment has extensive documentation, despite being banned for decades. Chronic, low-level exposure to pesticide residues in habitats weakens ecosystem health and productivity for all species, including humans. Organic production standards must adequately address problems associated with soil contaminants to protect soil health and productivity. The National Organic Standards Board must bring greater attention to the damage that contamination from widespread pesticide use causes, going beyond the focus on residues in the finished food commodities.
One way to reduce human and environmental contamination from pesticides is to buy, grow, and support organic. Numerous studies find that levels of pesticides in urine significantly drop when switching to an all-organic diet. Furthermore, given the wide availability of non-pesticidal alternative strategies, families, from rural to urban, can apply these methods to promote a safe and healthy environment, especially among chemically vulnerable individuals or those with health conditions. For more information on why organic is the right choice for both consumers and the farmworkers that grow our food, see Beyond Pesticides webpage, Health Benefits of Organic Agriculture.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: Yakima Herald (Press Release); Yakima Herald (Report)
