08
Jun
Climate Crisis Unleashes Pesticide Contamination from Thawing Permafrost, Elevating Global Emergency
(Beyond Pesticides, June 8, 2023) A study published in Nature Communications finds that climate-induced thawing of permafrost (a ground that remains completely frozen for two or more years) threatens approximately 4,500 industrial sites in regions of the Arctic. These thousands of industrial sites used to store hazardous substances have an estimated 13,000 to 20,000 contaminated locations. Not only do these regions pose a grave ecological risk to the Arctic, but they threaten the entire globe.
Many studies warn that thawing permafrost in the Arctic region can prompt the reemergence of greenhouse gases (e.g., methane and carbon dioxide), microbes, and hazardous chemicals (e.g., banned pesticides like DDT, heavy metals, etc.). Gases, microbes, and chemicals can drift near the poles, becoming entrapped in ice under the accumulating snowfall. As the global climate continues to rise and the climate crisis worsens, studies like this heed warning of potential adverse effects as ice encapsulating these toxic chemicals melt. Upon melting, some chemicals can volatilize back into the atmosphere, releasing toxicants into the air and aquatic systems, with the ensuing consequences. Microbes frozen for thousands to millions of years can also emerge from thawing permafrost, with unknown implications on human, animal, and ecosystem health. The melting permafrost is already beginning to impact infrastructure, creating sinkholes that damage roads, trees, and utility poles. Moreover, mixtures of hazardous chemicals, microbes, and greenhouse gases (GHGs) in permafrost are difficult to assess. Therefore, studies like this highlight the need to evaluate the health and ecological effects of melting arctic permafrost (and glaciers) from anthropogenic (human)-induced climate change.
The study forewarns, “Ongoing climate warming will increase the risk of contamination and mobilization of toxic substances since about 1100 industrial sites and 3500 to 5200 contaminated sites located in regions of stable permafrost will start to thaw before the end of this century. This poses a serious environmental threat, which is exacerbated by climate change in the near future. To avoid future environmental hazards, reliable long-term planning strategies for industrial and contaminated sites are needed that take into account the impacts of climate change.” [For related pieces, see Silent Snow: The unimaginable impact of toxic chemical use and DDT in Glacial Melt Puts Alaskan Communities at Risk.]
The study compiles numerous pan-Arctic (throughout the Arctic) industrial sites in permafrost-dominated regions to determine how many contaminated areas are within these industrial sites. Using the Northern Hemisphere Permafrost Map, researchers determined only areas with a permafrost occurrence probability of over 50 percent are viable study domains. Data from Alaska’s industrial regions established possible types of toxic substances within the regions. Climate prediction scenarios estimate the number of contaminated areas within the industrial sites that will experience direct effects from thawing permafrost. Thus, the study results demonstrate that melting permafrost poses a significant risk to the environment through the release of toxic substances. More than half of all existing contaminated sites are from the energy and industrial product processing and use sector. However, these sectors only account for 20 percent of all industrial sites. A majority of known industrial sites have been in the agriculture, forestry, and other land (AFOLU) use sectors that employ synthetic, petroleum-based pesticide management.
Many scientists consider Arctic environments “pristine,” void of chemicals used in more temperate and industrial climates. However, the Arctic has become a sink for these toxic chemicals, as studies find evidence that airborne Arctic chemical concentrations are comparable to industrialized regions in the U.S., Europe, and Asia.
Other investigations have found the presence of chemicals and microbes in soil and ice samples taken from Arctic regions. The Arctic is highly susceptible to global pollution, as warmer air contaminated with industrial and agricultural chemicals from manufacturing regions moves poleward toward cooler air. Environmental pollutants can condense into snowflakes high in the atmosphere and deposit onto the Arctic surface. Although deposition of these chemicals via long-range atmospheric transport and condensation are significant contributors to Arctic contamination, the chemical properties allowing these substances to persist in the environment for so long are concerning. Some of these long-lived chemicals include regionally banned pesticides like DDT, heptachlor, and lindane, which are highly toxic to humans and animals, causing a range of adverse effects, from respiratory issues to nervous system disorders and birth deformities to various common and uncommon cancers. Banned chemicals remain a global issue, as much of the developing world still report usage. However, banned/past-use compounds are not the only Arctic contaminants. Current-use chemicals, like chlorpyrifos, dacthal (DCPA), and trans-nonachlor (a component of the banned insecticide chlordane) readily contaminate the Arctic, and continued use will result in an increased probability of atmospheric transportation and deposition of chemicals on Arctic glacier tops via precipitation. According to Brettania Walker, Ph.D., toxics officer at World Wildlife Fund’s Arctic Program, “Not only is chemical contamination increasing in the Arctic but also modern chemicals are now appearing in many Arctic species alongside older chemicals, some of them banned for [over 50] years.”
The climate crisis adds another level of concern, especially regarding passive pesticide and microbial exposure from snowmelt. Pesticide contamination is already an issue in the U.S., as results of the United States Geological Survey’s (USGS) and National Water-Quality Assessment (NAWQA) show that pesticides and their breakdown products are present in all U.S. streams and widespread in groundwater throughout the country. For instance, a Chicago-based 2020 study shows black women who consume more tap water daily have higher bodily residues of the DDT metabolite (DDE). Permafrost and glacial melting will only add to water source contamination as volatile chemicals can enter waterways at the same concentration levels prior to ice entrapment, even after several decades. Moreover, several banned chemicals are not soluble in water (e.g., DDT, lindane, chlordane) but bioaccumulate in the fatty tissue of many Arctic species, such as polar bears, seals, whales, and some fatty fish like salmon, herring, and catfish. The level of DDT in Arctic penguins’ blubber is similar to levels during the initial banning more than 30 years ago. Unfortunately, some indigenous tribes in Arctic regions rely on these very mammals and fish for sustenance, and ingesting these pollutants is inevitable, putting their health at risk. Higher bodily concentrations of chemicals are evident in those who consume contaminated meat with associated health risks, including immune system disorders, increased susceptibility to disease, central nervous system disorders, learning disabilities among children, reproductive issues, and cancer. Studies find that adults and children who regularly consume fish from contaminated streams are at increased risk of disease from dietary and cumulative exposure, in many cases above EPA thresholds.
This study adds to the growing body of literature demonstrating disproportionate warming in arctic regions. Arctic thawing has implications for carbon release and landscape changes that are difficult to predict, including alternations in arctic vegetation and density. This study further highlights that permafrost’s bearing capacity (capability of the soil to support above-ground infrastructure) loses integrity close to 0 °C or 32 °F. Earth’s polar regions are warming the fastest, approximately two to four times faster than average, and these changes can have a cascading adverse impact on lower and higher latitudes. The scientists note that the polar regions (Arctic and Antarctic) stabilize Earth’s climate and drive heat transfer, powering jet streams and other fluxes/currents. Thus, polar warming has future consequences that threaten regular weather, climate, and chemical exposure patterns. According to Beyond Pesticides, which covers pesticide (and other kinds of) chemical pollution, “These results underscore a grim twin reality to the human-caused climate emergency and should be a dire warning on the state of our shared environment and a time for a systemic movement to eliminate fossil fuel-based pesticides and fertilizers.”
The climate crisis will lead to the melting of permafrost at both old and new pan-Arctic industrial sites through the discharging of hazardous contaminants, posing a threat to ecosystem services. The study notes, “The effects of thawing permafrost, with all its consequences, such as loss of hydrological barriers, improved hydrological connectivity, reduced soil stability, and strongly impeded site accessibility for clean-up measures, will often occur after the operating period of industrial sites. This [issue] underscores the need to avoid leaving environmentally hazardous substances at the sites, as permafrost can no longer be considered a reliable barrier to their containment. Furthermore, long-term remediation strategies will be necessary for contaminated legacy sites that have already been closed if they still contain hazardous substances.”
As global warming progresses, exposure concerns will increase significantly, especially for those more vulnerable to the toxic effects of chemical exposure. To mitigate the risks associated with chemical exposure from pesticides, advocates say the manufacturing and use of pesticides need addressing, first and foremost. Global leaders must curtail the continued manufacturing of chemical pollutants that readily contaminate polar regions. Recently, agrochemicals like pesticides and fertilizers overtook the fossil fuel industry as the leading contributor to environmental sulfur emissions. If pesticide use and manufacturing are amplifying the impacts of the climate crisis, advocates argue that it is essential to incite change by enhancing pesticide policy and regulation that eliminates use.
A switch from chemical-intensive agriculture to regenerative organic agriculture can significantly reduce the threat of the climate crisis by eliminating toxic, petroleum-based pesticide use, building soil health, and sequestering carbon. The Intergovernmental Panel on Climate Change (IPCC) finds that agriculture, forestry, and other land use contribute about 23% of total net anthropogenic emissions of greenhouse gases. However, organic production reduces greenhouse gas emissions and sequesters carbon in the soil. Learn more about switching to organic management practices by reading Regenerative Organic Agriculture and Climate Change: A Down-to-Earth Solution to Global Warming. For more information about organic food production, visit the Beyond Pesticides Keep Organic Strong webpage. Learn more about the adverse health and environmental effects chemical-intensive farming poses for various crops and how eating organic produce reduces pesticide exposure.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: Nature Communications
