(Beyond Pesticides, August 24, 2022) New research is helping the medical community understand the mechanism through which exposure to the banned insecticide DDT increases risk of Alzheimer’s disease. Published in the journal Environmental Health Perspectives, a team of researchers from Florida International University and Rutgers used multiple models to demonstrate the effects of DDT on the production of toxic proteins in the brain. The constant stream of new health risks regarding a chemical banned decades ago underlines the importance of a precautionary approach to pesticide regulation, particularly as red flags are already being raised about the connection between widely used weed killers like glyphosate and neurodegenerative diseases like Alzheimer’s. “The vast majority of research on the disease has been on genetics — and genetics are very important — but the genes that actually cause the disease are very rare,” says study coauthor Jason Richardson, PhD of Florida International University. “Environmental risk factors like exposure to DDT are modifiable. So, if we understand how DDT affects the brain, then perhaps we could target those mechanisms and help the people who have been highly exposed.” Previous research from Dr. Richardson found that DDT exposure increased risk of Alzheimer’s by four times. Scientists […]

(Beyond Pesticides, August 11, 2022) A study in the International Journal of Environmental Research and Public Health finds that Brazilian agricultural workers are more likely to die from acute kidney failure (AKF) than other acute illnesses. Among the agricultural workers, the prevalence of AKF is higher for individuals at younger ages, who are female, and located in regions south of chemical use, particularly rural areas. However, the AKF mortality rate in urban areas is also increasing, but not as fast as in rural areas. Over six million people in the U.S. have kidney disease (i.e., nephritis [kidney inflammation], nephrotic syndrome (improper protein filtration), and nephrosis). Although many studies find an association between exposure to environmental contaminants like pesticides and chronic kidney disease (CKD), the association between pesticides and acute kidney failure remains unclear. CKD is a risk factor for AKF, and other environmental factors can increase the risk of AKF mortality. Therefore, studies like this highlight the need for comprehensive information regarding co-occurring exposure patterns and disease prevalence that can have global implications. The study notes, “Our findings reinforce the need for more robust epidemiological studies that account for co-exposures and conditions of agricultural work in the relationship between pesticide exposure and kidney […]

(Beyond Pesticides, July 21, 2022) Research published in Scientific Reports finds an association between the increasing emergence of nonalcoholic fatty liver disease (NAFLD) and exposure to endocrine (hormone) disrupting chemicals, like organochlorine pesticides (OCPs). It is well-known that traces of legacy (past-use) pesticides, like organochlorines, remain in the environment for decades—possibly centuries, post-final application, as OCPs have greater chemical stability and gradual attenuation. However, these chemicals have profound adverse impacts on human health, especially on the endocrine system. Obesity, insulin resistance, type 2 diabetes, and elevated liver enzyme resulting from endocrine disruption contribute to NAFLD and can lead to liver cirrhosis. Although some, but not all, manufacturing and use of specific OCPs have declined in the U.S., OCPs remain a global issue, as much of the developing world still reports usage. Considering the lack of studies on OCP-induced endocrine disruption and NAFLD, research like this highlights the need to understand the underlying mechanisms that contribute to growing endocrine disease incidents.   The study determined that there is an association between OCP exposure and NAFLD using the fatty liver index (FLI), a predictor of lipid (fat) accumulation in the liver. The researcher collected blood serum to measure the concentration of OCPs, specifically evaluating detectable […]

(Beyond Pesticides, July 12, 2022) More than four out of five U.S. children and adults over the age of six have detectable levels of glyphosate in their bodies, according to data recently published by the Centers for Disease Control and Prevention (CDC). With strong evidence implicating this chemical as a carcinogen, and emerging data associating it with adverse birth outcomes, the findings raise broad concerns for public health. As the U.S. Environmental Protection Agency (EPA) continues to permit widespread public exposure to toxic chemicals based on obscure economic arguments over the claimed benefits of pesticides, advocates say it is time for a change that embraces health and the environment over the profits of pesticide manufacturers. CDC’s testing data was developed as part of its National Health and Nutrition Examination Survey (NHANES), a long-running program that began in the early 1960s and has since become a continuous program focused on American health and nutrition measurements. Data from this program are subsequently analyzed to help inform the prevalence of disease in the U.S. population and are used to develop public health policies. A total of 2,310 urine samples retained from studies conducted in 2013-2014 were analyzed by NHANES researchers for the presence […]

(Beyond Pesticides, July 7, 2022) A review article published in the International Journal on Environmental Sciences highlights how pervasive pesticide exposure and climate change threaten global species biodiversity. Now more than ever, people are changing their sentiment toward sustainability, with two-thirds of consumers stating the importance of limiting climate change impacts and 88 percent supporting greater pollution reduction. The relationship between climate change and biodiversity—a “distinct but related issue”— is often overlooked in the regulation of the pesticide industry. Climate change and biodiversity loss are interdependent, and an adverse impact on one can bolster adverse effects on the other. Biodiversity is intricate and affects all environmental ecosystems—from oceans and freshwater to forests and soils; it encompasses all life forms on earth. Without biodiversity, food production, energy production, clean water, fertile soil, sustained air quality, and climate will suffer. The globe is currently going through the Holocene Extinction, Earth’s 6th mass extinction, with one million species of plants and animals at risk. With the increasing rate of biodiversity loss, advocates say it is essential for government agencies to hold the pesticide industry accountable for the direct (i.e., excessive agrochemical use) and indirect (i.e., water pollution from run-off) impacts on ecosystems. The review notes, “The enormous use […]

(Beyond Pesticides, June 30, 2022) A study by Zhongnan University and Shandong University in China finds that the broad-spectrum fungicide maneb increases Parkinson’s disease (PD) risk and development through alterations in protein and metabolite pathways, resulting in neurotoxicity. Several studies find exposure to chemical toxicants, like pesticides, have neurotoxic effects or exacerbate preexisting chemical damage to the nervous system. Although the mechanism by which pesticides induce disease development remains unclear, this study suggests neurological damage from oxidative stress, cell dysfunction, and synapses impairment, among others, increases the incidence of PD subsequent to pesticide exposure. Parkinson’s disease is the second most common neurodegenerative disease, with at least one million Americans living with PD and about 50,000 new diagnoses annually. The disease affects 50 percent more men than women, and individuals with PD have a variety of symptoms, including loss of muscle control and trembling, anxiety and depression, constipation and urinary difficulties, dementia, and sleep disturbances. Over time, symptoms intensify, but there is no current cure for this fatal disease. While only 10 to 15 percent of PD cases are genetic, PD is quickly becoming the world’s fastest-growing brain disease. Therefore, research like this highlights the need to examine molecular mechanisms involved in altering chemical […]

(Beyond Pesticides, June 22, 2022) Bad news is piling up for Bayer (Monsanto) and its carcinogenic flagship weed killer, glyphosate (Roundup). Last week, the Court of Appeals for the Ninth Circuit handed down a ruling that held the U.S. Environmental Protection Agency’s (EPA) 2020 approval of its notorious weed killer glyphosate unlawful. Then, yesterday, the U.S. Supreme Court declined to consider (deny certiorari) Bayer’s “Hail Mary” petition attempt to save the company from being held accountable to those diagnosed with cancer after using Roundup (glyphosate) herbicides. In both cases, the courts are acting as a check on a company, while EPA regulators charged with stopping this behavior continue to rubber stamp the agrichemical industry’s dangerous decisions. This is not the first time that the Supreme Court has upheld the rights of victims of the pesticide industry. In 2004, Bates v. Dow Agrosciences (U.S. Supreme Court, No. 03-388), the court found: “The long history of tort litigation against manufacturers of poisonous substances adds force to the basic presump­tion against pre-emption. If Congress had intended to deprive injured parties of a long available form of compen­sation, it surely would have expressed that intent more clearly. See Silkwood v. Kerr-McGee Corp., 464 U. […]

(Beyond Pesticides, June 21, 2022) June 20-24 is Pollinator Week, during which we recognize—and take action to protect—this important ecosystem link. Pollinators––bees, butterflies, birds, bats, and other organisms––make a critical contribution to plant health, crop productivity, and the preservation of natural resources, but their existence is threatened by their pesticide-contaminated habitat. Pesticides have consistently been implicated as a key contributor to dramatic pollinator declines. Of the 100 crop varieties that provide 90% of the world’s food, 71 are pollinated by bees. Honey bees alone pollinate 95 kinds of fruits, nuts and vegetables, such as apples, avocados, almonds, and cranberries. Take action to protect pollinators. Providing protection for pollinators also protects the ecosystem in which they live. That protection requires eliminating harm as well as providing safe habitats where they can live and reproduce.  Provide organic habitat on your own property and encourage your town to go organic. Since plant starts in many garden centers across the country are grown from seeds coated with bee-toxic neonicotinoid pesticides, or drenched with them, Beyond Pesticides has compiled a comprehensive directory of companies and organizations that sell organic seeds and plants to the general public. Included in this directory are seeds for vegetables, flowers, and herbs, as well as […]

(Beyond Pesticides, June 19, 2022) On Juneteenth Day, we commemorate the abolition of slavery and celebrate human freedom. At the same time, we recognize that we have significant work to do to eliminate systemic racism and advance environmental justice. We strive to ensure that people of color are not disproportionately harmed by pesticides and other toxic chemicals—from production, use, to disposal—and that all people have access to sustainable and organic food and organically managed communities. Acute and chronic exposure to chemicals like pesticides cause a plethora of harmful effects, including (but not limited to) brain and nervous system disorders, birth abnormalities, cancer, developmental and learning disorders, endocrine disruption, immune disorder, and reproductive dysfunction, among others. However, people of color may experience more servere health effects from exposure, resulting in elevated rates of diseases. Communities of color and those living in low-socioeconomic conditions experience an inequitable number of hazards, including toxic waste plants, garbage dumps, and other sources of environmental pollution and odors that lower the quality of life. Therefore, these populations experience greater exposure to harmful chemicals and suffer from health outcomes that affect their ability to work and learn. When discussing health disparities and environmental justice, we need to […]

(Beyond Pesticides, June 2, 2022) A California judge ordered state-run pesticide spraying to cease on public, agricultural, wild lands, and private properties. The judge states that government officials fail to consider and minimize the potential health and environmental risk associated with pesticide use. Moreover, officials failed to notify the public on the risks of pesticide spraying. The suit was brought by the Environmental Working Group (EWG), the City of Berkeley and ten other public health, conservation and food safety organizations, including Beyond Pesticides. Board member of the California Environmental Health Initiative Nan Wishner states, “The court made the right decision to throw out CDFA’s plan to cement into place for the indefinite future the agency’s ‘spray now, ask questions later approach to pest management, which would have perpetuated the existing situation, in which Californians learn their yards or neighborhoods are to be sprayed only when the treatments are about to happen and have little or no recourse to stop the use of pesticides.”  On May 19, 2022, the Superior Court of California – County of Sacramento ruled to remove an environmental impact report allowing California’s Department of Food and Agriculture (CDFA) to spray pesticides at any time and any place. Removal […]

(Beyond Pesticides, May 27, 2022) In a U.S. Environmental Protection Agency (EPA) court document filed on May 16, the agency signaled potential changes to the labeling it requires for “over the top” (OTT, or post-emergent) herbicides containing dicamba, a very problematic pesticide. The filing — in U.S. District Court for the District of Arizona, where EPA currently faces litigation about its 2020 dicamba registrations — comes as a result of Bayer, Inc.’s March 2022 proposed amendments to EPA registration for its XtendiMax herbicide, which contains dicamba and glyphosate. Beyond Pesticides has covered the dicamba saga for years, including the EPA Office of the Inspector General’s critical 2021 report citing an abandonment of science and assault on agency integrity for EPA’s dicamba decisions during the Trump years. Dicamba has been linked to cancer, reproductive effects, neurotoxicity, birth defects, and kidney and liver damage. It is toxic to birds, fish, and other aquatic organisms, and is known to leach into waterways after application. Dicamba also causes serious damage to non-GE (genetically engineered), non-target plants, damaging habitat and food sources for various organisms, especially for birds and insects. According to Progressive Farmer, EPA is currently considering some dicamba use restrictions after Bayer submitted them to […]

(Beyond Pesticides, May 26, 2022) A study published in The International Journal of Biochemistry & Cell Biology finds environmental exposure to neurotoxic pesticides increases Parkinson’s Disease (PD) risk through gastrointestinal (GI) disruption. Research finds exposure to chemical toxicants, like pesticides, can cause neurotoxic effects or exacerbate preexisting chemical damage to the nervous system. Although the mechanism by which pesticides induce disease development remains unclear, this study suggests environmental pesticide exposure disrupts GI cells responsible for supporting the autonomic nervous system. Enteric glial cells (EGCs) are GI cells that play a critical role in the functional changes that accompany GI dysfunction, as this dysfunction is one of the earliest symptoms indicating the onset of PD. Parkinson’s disease is the second most common neurodegenerative disease, with at least one million Americans living with PD and about 50,000 new diagnoses each year. The disease affects 50% more men than women, and individuals with PD have a variety of symptoms, including loss of muscle control and trembling, anxiety and depression, constipation and urinary difficulties, dementia, and sleep disturbances. Identifying early biomarkers of PD, such as pesticide-mediated toxicity on GI cells, is crucially important as symptoms intensify overtime, with no current cure for this fatal disease. While only […]

(Beyond Pesticides, May 24, 2022) New research is providing strong causal evidence that Gulf War Illness (GWI) is the result of exposure to sarin gas, an organophosphate nerve agent used by Saddam Hussein as a chemical weapon during the Gulf War. The findings, published earlier this month in Environmental Health Perspectives, have important implications for the hundreds of thousands of American service members suffering from a constellation of chronic symptoms without a true understanding of how they became sick. “Quite simply, our findings prove that Gulf War illness was caused by sarin, which was released when we bombed Iraqi chemical weapons storage and production facilities,” said Robert Haley, MD, lead author of the study and epidemiologist at University of Texas Southwestern. “There are still more than 100,000 Gulf War veterans who are not getting help for this illness and our hope is that these findings will accelerate the search for better treatment.” Sarin was first synthesized in the late 1930s by Nazi chemists working for IG Farben (a consortium that included Bayer) in an attempt to create stronger and more powerful insecticides. Sarin is a G-series organophosphate (named after the scientists that created them), characterized by high acute toxicity and […]

(Beyond Pesticides, May 20, 2022) Beyond Pesticides has long covered the various ways in which corruption related to pesticides, agriculture, and food — whether in industry or government — can result in harm to human and environmental health, including to a multiplicity of organisms, and their ecosystems and habitats. In this Daily News Blog entry, we will review the landscape of U.S. pesticide regulation, examples of corruption, and what can be done to counter it. A look at some recent instances provides unfortunate assurance that problems of corruption at EPA persist. A serious flaw in EPA’s registration (and periodic pesticide registration review) processes is their reliance on industry-provided data and research on safety of pesticide products, which does not reliably represent actual risks of harms. Agrochemical companies sometimes purchase research that yields biased or distorted findings, cherry pick results in their submissions to EPA, or try to suppress research findings. USRTK recently covered an instance in which Bayer (and other companies) funded a study on the impacts — of use of their neonicotinoid (neonic) corn seed treatments — on bees during planting season. Neonics have been widely implicated in the plummeting health, function, and populations of pollinators and in the so-called […]

(Beyond Pesticides, May 9, 2022) While the U.S. Environmental Protection Agency (EPA) updated its guidelines for pollinator risk assessments in 2014, the agency continues to either fail to conduct full assessments, or dismiss concerning data it receives. EPA appears to discount threats like the insect apocalypse, evidenced by a 75% decline in insect abundance, which threatens not only global ecosystems, but also food production that depends on animal pollination. As pesticides move through the food web, birds are also at risk. Bird numbers are down 29% since Rachel Carson wrote Silent Spring in 1962. Tell EPA To Protect Against Other Threats to Pollinators. Tell Congress To Insist that EPA Does Its Job. The problem is highlighted by EPA’s recent Interim Decision on fenbuconazole, in which the agency notes that, “For larval bees, RQs (risk quotients) exceed the LOC (level of concern) for all pollinator attractive uses including when assessed at the lowest application rate of 0.0938 lb a.i./Acre (RQ = 1.1).” Yet in the same document, the agency declares that “…the benefits of fenbuconazole (e.g., efficacy in management of fungal pathogens) outweigh any remaining risk and that continuing to register fenbuconazole provides significant benefits, including its ability to increase crop […]

(Beyond Pesticides, May 5, 2022) A report published in Biological Conservation finds environmental pollutants, including pesticides, pharmaceuticals, plastics, and particulate matter, adversely affect tropical terrestrial wildlife. Specifically, these contaminants can interact with one another, altering the chemical landscape of the ecosystem, and causing changes in the endocrine and microbiome systems of mammals. Since the publication of Rachel Carson’s Silent Spring (1962), global attention to the danger of pesticides has increased, with environmental agencies banning the use of legacy pesticides like organochlorines for their devastating toxic—sometimes lethal—effects. However, these chemicals can remain in the environment for decades and interact with various current-use pesticides, including organophosphates, neonicotinoids, and pyrethroids. Although many studies demonstrate that environmental pollution plays a significant role in premature deaths among humans, there is a lack of research on how environmental pollution directly affects tropical species mortality. Considering human and wildlife habitats tend to overlap, and chemical pollutants can drift from chemically treated areas, wildlife populations are more likely to experience similar health effects. With the number of chemicals in the ecosystem growing, studies like these highlight the need for pesticide policies that protect human health in addition to the integrity of the chemical landscapes accommodating wildlife. The researchers note, “Using […]

(Beyond Pesticides, May 3, 2022) Exposure to a commonly used fungicide considered to be ‘slightly toxic or nontoxic’ to pollinators makes male mason bees less likely to find a mate, jeopardizing future generations of critically important pollinators. This determination comes from research recently published in the Journal of Applied Ecology by scientists at Germany’s University of Würzburg. The timing of these findings comes after the U.S. Environmental Protection Agency (EPA) reapproved uses of fenbuconazole, the fungicide in question, late last year without completing all required studies on pollinator health effects. Horned mason bees (Osmia cornuta), a solitary bee species, have a complex mating process that includes a range of “pre-copulatory behaviors” used by male bees attract females. Males create thoracic vibrations with their flight muscles, rub the eyes of female bees with their antennae, and emit a distinct odor from their body. If the female likes the presentation, she will mate with the male. Otherwise, she will move him to the side and wait for another male to try to win her affection. To see how this process was influenced by pesticide exposure, researchers conducted a range of different experiments. For the first, newly emerged male and female bees were […]

(Beyond Pesticides, April 29, 2022) The U.S. Fish and Wildlife Service’s (FWS’s) plan to list a rare milkweed species, and the areas in which it grows in south Texas, as critical and endangered has garnered political pushback from Texas Attorney General Ken Paxton. In February, FWS announced its intention to list 691 acres of prostrate milkweed habitat in order to protect it, given its critical role in supporting monarch butterfly populations. But Attorney General (AG) Paxton sent a letter to FWS saying that the critical and endangered determination “would further destabilize Texas’s border, hindering the construction of the border wall,” and that it would risk security on the border with Mexico. FWS countered with a press release stating that, “This listing and critical habitat proposal is based on the best available science, including a species status assessment that included input and review from academia and state agencies.” The 1973 Endangered Species Act (ESA) mandates that federal agencies, in consultation with FWS and/or the U.S. National Oceanic and Atmospheric Administration (NOAA) Fisheries Service, ensure that any actions in which they engage (whether authorizing, implementing, or funding) are unlikely to jeopardize the existence of a listed species, or have negative impacts on […]

(Beyond Pesticides, April 20, 2022) A University of Michigan study is the first to highlight that maternal pesticide exposure during pregnancy adversely affects sleeping patterns for offspring later in life, specifically for females. Prenatal development is one of the most vulnerable periods of exposure as the fetus is most susceptible to the harmful effects of chemical contaminants. Many studies indicate that prenatal and early-life exposure to environmental toxicants increases susceptibility to diseases, from learning and developmental disabilities to cancer. However, the toxicity of pesticide exposure ad its full impact on the nonagricultural population in the U.S., especially women. Given research links to sleep-related disorders and neurological and cognitive development, studies like this can help government and health officials identify how pesticides’ impact on the brain elevates health concerns. The authors note, “Overall, these results are of public health importance considering the continued widespread agricultural and possibly residential use of pyrethroids and chlorpyrifos [in Mexico]…Thus, our results underline the importance of additional research studies that include both larger samples and assessment of unregulated pesticides, as well as studies that consider the underlying mechanisms explaining sex differences.” Levels of inadequate sleep patterns are rising among children and adolescents. Reports find variability in sleep duration results in higher rates of depression, anxiety, and […]

(Beyond Pesticides, March 25, 2022) Recent coverage by The Guardian of the U.S. Environmental Protection Agency’s (EPA’s) plan — to extend the registration of several demonstrably harmful neonicotinoid insecticides — compels Beyond Pesticides to identify, once again, the agency’s failures to enact its core mission. That mission is “to protect human health and the environment,” and to ensure that “national efforts to reduce environmental risks are based on the best available scientific information.” EPA has undertaken a review of the registration of several members of the neonicotinoid (neonic) family of pesticides and, despite the agency’s own findings of evidence of serious threats to pollinators, aquatic invertebrates, and other wildlife, it issued interim decisions on these neonics in January 2020 that disregard the science on the pesticides’ impacts. EPA appears to be prepared to finalize these registrations late in 2022; this would, barring further action, extend the use of these harmful compounds for 15 years. Neonics are used widely in the U.S., both on crops to kill sucking insects, and as seed treatments with the same goal for the developing plant. These insecticides are systemic compounds, meaning that once applied, they travel to all parts of a plant through the vascular […]

(Beyond Pesticides, March 23, 2022) A study published in Nature Reviews Earth & Environment warns that thawing of permafrost (a ground that remains completely frozen for two or more years) in the Arctic region can prompt the reemergence of greenhouse gases (e.g., methane and carbon dioxide), microbes, and chemicals (e.g., banned pesticides like DDT). Past research finds gases, microbes, and chemicals 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 show significant effects, as ice encapsulating these toxic chemicals is melting. 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 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. […]

(Beyond Pesticides, March 18, 2022) A 2020 lawsuit related to pesticide drift was resolved on March 8, 2022 in San Joaquin (California) Superior Court with the finding that Alpine Helicopter Services, which specializes in pesticide applications for government and tourism entities, had violated pesticide drift laws and endangered public health and safety. The court further found Alpine liable for damage related to its actions, though penalties in the case, brought by California state prosecutors and the California Department of Pesticide Regulation (DPR), have yet to be determined. The case exposes a handful of the many instances of pesticide drift, also known as “chemical trespass,” that occur every year in the U.S. In 2004, Beyond Pesticides covered the issue with Getting the Drift on Chemical Trespass; its monitoring of drift issues is ongoing, as can be seen in its “Pesticide Drift” archives. The long history of nontarget exposure, contamination, and poisoning teaches that drift is a function of pesticide use, but not considered adequately by regulators who allow the marketing of poisons that are known to move through the environment uncontrolled. Cases like the Alpine case highlight a relentless problem associated with the daily use of pesticides. Pesticide drift is any airborne […]

(Beyond Pesticides, February 10, 2022) A National Institute of Environmental Health Sciences (NIEHS)-funded study finds that patterns of pesticide exposure among farmers have geographical and temporal significance. Specific use of and exposure to organophosphate and carbamate chemicals decrease enzyme activity within the body, resulting in greater health anomalies among farmers, especially during agricultural seasons. The use of xenobiotic (foreign chemical compounds) substances like pesticides and fertilizers in agriculture are increasing. Thus, those working with and around these toxicants must have protection. Considering that agricultural workers often experience pesticide exposure at higher rates due to occupation, long-term research must identify potential health concerns surrounding common pesticides. The study author, Dana Barr, Ph.D., states, “The majority of farmers in this study reported that they had at least one health symptom associated with pesticide intoxication. This investigation can be used to promote safer use of pesticides among farmers and mitigate exposure among residents living near a rice field. The findings will be critical for establishing and launching several preventive programs in the future.” Researchers evaluated the health effects of pesticide exposure among a cohort of farmers in Thailand during inactive and active rice farming periods. Using geographic information system (GIS) mapping, researchers compared […]