Bhopal Disaster Quiz

Nature of the Pest Problem

• Pests are organisms, animal or plant, that interfere with human well-being or interests.
• Pests act as vectors of disease.
• Pests cause discomfort.
• Pests compete for resources.
• Pests eat crops.
• Weeds steal nutrients from crops.

Impetus for Pest Control Tools

• The Irish potato famine of 1848 was caused by a fungus.
• Destruction of the French wine industry occurred due to insects and mildew.
• Coffee supplies were depleted by a fungus.
• The approximate number of people who died in the Irish famine was 800,000.

Coffee Leaf Rust Discovered on All Major Islands of Hawaii

• The highly contagious, crop-killing coffee leaf rust disease (CLR) has been discovered on all major Hawaiian islands.
• The rust-causing pathogen was discovered on the islands of Kauai, Molokai among others.
• Lab testing suggests that coffee leaf rust may have been present on Kauai for at least six months.
• A Kauai coffee farmer alerted the agency to the potential problem.
• Samples from Molokai were from feral coffee plants and likely affected for at least three months.
• Strict quarantine measures for agricultural products were put in place beginning in October 2021 despite the spread.

Early Chemical Agents for Pest Control

• Highly toxic inorganic compounds were used for pest control.
• Copper sulfate and lime were mixed to create Bordeaux mixture.
• Copper with arsenic was used as Paris Green.
• Lead arsenate contained arsenic as its active ingredient.
• Kerosene and oil suffocated insect larvae.
• Toxicity of heavy metals and other compounds led to research into alternatives.

Pesticides

• Pesticides are any substance or mixture of substances used to prevent, destroy, repel or mitigate any types of pest.
• Herbicides control plants, weeds, and grasses.
• Insecticides control insects and arachnids.
• Fungicides control fungal growth.
• Rodenticides control rodents.
• Nematicides control nematodes or roundworms.

Pesticide Sales

• Herbicides were the most sold pesticide in 2012, accounting for approximately 60% of sales and over $5 billion in expenditures in the agricultural sector.
• Insecticides ranked second in sales, despite more sales in the home/garden sector compared to the agricultural sector.
• Fungicides were the third-largest-selling pesticide category.

Herbicides

• Herbicides control weeds, plants, and grasses.
• Selective herbicides kill either broad-leaved plants or grasses but not both.
• 2,4-D was the first synthetic selective herbicide, used in Agent Orange during the Vietnam War.
• Atrazine is the most commonly used selective herbicide in US agriculture.
• Nonselective herbicides kill all types of plants and were used for clearing plant life, or are applied to individual weeds.
• Roundup is a nonselective herbicide used on lawns, targeting individual weeds.
• Roundup Ready soybeans were developed by Monsanto Corporation.

Insecticides

• Insecticides control vectors of human or animal diseases.
• Insecticides are primarily used against mosquitoes, flies, fleas, and ticks.
• Insecticides are used to prevent pests from consuming crops.
• Insecticides poison pests when they ingest or come in contact with the insecticide.
• Organochlorine pesticides, such as chlordane, aldrin, dieldrin, heptachlor, and DDT, are nerve toxins that affect the central nervous system of pests, cause convulsions, and death.
• Organochlorines have low acute toxicity to humans and have persistent effects on the environment; they concentrate in fatty tissues and biomagnify in the food chain.

Dichlorodiphenyltrichloroethane (DDT)

• DDT is an organochlorine pesticide/insecticide.
• It was created around 1940.
• Dr. Paul Müller won the 1948 Nobel Prize for his work with DDT.
• DDT was extensively used by the US military in World War II.
• It was initially viewed as a beneficial chemical, due to its helpfulness in communities with malaria and its effectiveness in protecting against pests.
• DDT is persistent; it lasts long.
• DDT is now widely banned due to its environmental impacts.

Organophosphates

• Organophosphates are the second generation of synthetic organic insecticides.
• They were initially developed as nerve gases.
• Organophosphates are used in a variety of products, such as baits, sprays, foggers, flea collars, and granules.
• Like organochlorines, they disrupt the central nervous system.
• They disrupt an enzyme, stopping it from working.

Organophosphates (Continued)

• Organophosphates frequently cause fatal poisonings, particularly among agricultural workers.
• Organophosphates are less persistent in the environment compared to organochlorines.
• Examples include parathion, malathion, Dursban, Diazinon (banned in 2005), and chlorpyrifos (banned for consumer purchase in CA in 2020).

Carbamates

• Carbamates are closely related to organophosphates.
• They have low short-term toxicity to humans.
• They break down into other substances quickly.
• Methyl isocyanate (MIC) is an intermediate chemical used in the manufacture of carbamate pesticides.
• MIC is extremely toxic, as seen in the 1984 Bhopal, India disaster, where an accident resulted in estimated 3,000-5,000 deaths immediately, and ~15,000 more over time.
• Carbamates are used to control garden pests, and are found in tick and flea products for pets.
• Examples include Carbyl (Sevin), Aldicarb, Fenoxycarb, Propoxur, Metam sodium.

Pyrethroids

• Pyrethrum is extracted from chrysanthemums.
• Pyrethroids are synthetic versions of pyrethrum.
• Pyrethroids impair the nervous system.
• They paralyze and kill flying insects.
• They interfere with the transmission of nerve impulses.
• Pyrethroids are often used in community-level spraying to control vector-borne diseases, such as West Nile Virus.
• Pyrethroids are also used in agriculture, mosquito repellents, insecticide bombs, pet treatments, and lice treatments.
• Examples include permethrin, allethrin, resmethrin, and cyfluthrin.

Limitations of Pesticides

• Pesticide resistance is similar to bacterial resistance, with some pests developing a genetic tolerance to pesticides.
• Due to shorter life spans, pests evolve resistance quickly, leading to decreased effectiveness.
• Pesticides can kill other species aside from the target pest.
• This may lead to the resurgence of the target pest or to the development of secondary pest outbreaks.

Human Health Effects of Pesticides

• Studying the chronic effects of pesticides is difficult.
• Pesticide intake is hard to accurately estimate.
• The mix of chemicals and varying practices by workers make accurate assessment hard.
• Epidemiologists use farming as a surrogate for pesticide exposure to study effects.
• Pesticides are closely linked to neurological effects, such as headaches, nausea, vomiting, and muscle weakness.
• Pesticide exposure has also been linked to Parkinson's disease, memory issues, and attention problems, as well as various cancers.
• Concerns also include reproductive and development outcomes such as spontaneous abortion, stillbirth and premature births, reduced semen quality, and oral clefts.

Disparities in Exposures and Impacts

• Pesticide exposure disproportionately affects certain populations, especially pesticide production workers, farmers and their families, and hired farmworkers.
• In the US, hired farmworkers are mostly men with a significant number of Hispanic and foreign-born individuals who have issues with language barriers and inadequate protections from hazardous pesticide chemicals.
• In lower-income countries, more hazardous pesticides may still be used.
• Female agricultural workers without proper training of protection are at higher risk.

Integrated Pest Management (IPM)

• IPM uses multiple tactics to suppress pests.
• It involves setting thresholds based on monitoring, triggering action.
• IPM encourages beneficial insects, synthetic pheromones, and adjustments to irrigation or crop rotation practices.

Benefits of Modern Chemical Pesticides

• Increase crop yields.
• Fewer rodent problems.
• Decrease major diseases (i.e. malaria)

Significant Drawbacks to Pesticides

• Development of pesticide resistance by pests.
• Killing of beneficial species.
• Persistent environmental contamination.
• Concerns about residual pesticide contamination in food.
• Risks to human health (e.g. allergies, cancers, Parkinson's Disease)

Key Features of U.S. Agriculture Today

• Few varieties of crops are mostly grown in monoculture.
• Heavy reliance on chemicals and machinery.
• Subsidized by fossil fuels, with pesticides and fertilizers derived from petroleum.
• Heavy reliance on machinery.

Nitrogen Contamination

• Extensive use of nitrate fertilizers leads to nitrites in groundwater.
• Ingesting nitrites changes hemoglobin's ability to carry oxygen.
• This can result in blue baby syndrome.

Genetically Modified Crops

• GM crops aim to increase global food supply by enhancing disease, pest resistance, and faster ripening.
• Gene isolation is followed by transgene transfer into a different species' DNA.
• Key concerns are allergic reactions and the potential spread of antibiotic resistance.

Use of Water for Irrigation

• Irrigation accounts for 42% of U.S. water consumption based on data from 2015.
• Substantial water is lost via evaporation.
• Key areas of concern include the Lower Colorado River, Rio Grande region, Central Plains, and the Southwest, where the consumption of water exceeds renewable supplies and water exploitation is prominent.

Mechanical Hazards to Workers

• Approximately 250 fatal injuries occur annually in the U.S agricultural workforce primarily from transport or equipment-related hazards.
• Nonfatal injuries (e.g., being struck by equipment, hand/foot injuries caused by human error) are also prevalent due to haste or similar factors.

Bhopal, India: Explosion of Pesticide Plant

• A significant pesticide plant explosion occurred in Bhopal, India in December 1984, releasing around 45 tons of methyl isocyanate (MIC) gas.
• The gas spread to densely populated areas and resulted in significant immediate and long-term health impacts.
• Thousands died immediately, and hundreds of thousands suffered long-term illnesses, including respiratory problems, eyesight issues, and others.
• Outdated equipment, inadequate management, and safety procedures were contributing factors to the disaster.
• Compensation was limited.

Intergenerational Impact of Bhopal Accident

• Within three years of the disaster, a decrease in male births was observed, as well as men in the womb at that time showing more disabilities that affected their employment in the following decades.
• Long-term effects, observed more than 30 years later, showed a significant increase in cancer rates and a reduction in education levels for men exposed to the disaster.

Test your knowledge on the Bhopal disaster, one of the world's worst industrial accidents. This quiz covers its primary causes, immediate health impacts, and long-term health risks associated with exposure. Dive into the important facts and implications of this tragic event.