Biological Hazards, Pesticides, and Environmental Risks in Public Health

What is a biological hazard (biohazard)?

A biological substance that poses a threat to living organisms, especially humans, including microorganisms, viruses, toxins, and allergens.

Where can biological hazards be found?

Naturally in the environment and in various work sectors such as healthcare, veterinary services, agriculture, sewage management, laboratories, and construction.

Give an example of a biological hazard found in building water systems.

Legionella bacteria.

What are some health effects of biological hazards?

Diseases ranging from the common cold to life-threatening infections, poisonings, and allergic reactions.

What are the routes of transmission for biological hazards?

Injection, absorption, ingestion, and inhalation.

What is one way biological hazards can be transmitted via injection?

Through contaminated sharps like needles or animal bites.

How can biological hazards be transmitted through absorption?

Through skin contact, hand-to-face contact, or splashes to eyes/nose/mouth.

What are two examples of diseases caused by viruses?

Chickenpox and COVID-19.

What type of biological hazard reproduces via airborne spores?

Fungi.

What are toxins from biological sources?

Poisons produced by living organisms such as bacteria, fungi, plants, insects, and animals.

What is an example of a protozoan biological hazard?

The malaria parasite.

How can biohazards be identified in the workplace?

Byproducts or contaminants of work processes, environmental sources, communicable diseases, or intentional work with biohazards.

What is the hierarchy of controls for managing biohazards?

Personal protective equipment (PPE), behavior change, environmental controls, and medical interventions.

What prompted the new standards for biological hazards?

The COVID-19 pandemic highlighted the threat of biological hazards to all, especially frontline workers.

What are the two instruments that come from the new standards for biological hazards?

A convention that is binding once ratified and a recommendation that provides practical guidance.

What is one aim of the new standards for biological hazards?

To provide comprehensive protection and actionable advice for vulnerable groups.

What role do governments have in relation to the new biological hazard standards?

To ratify the convention and enact national laws/regulations in line with it.

What is the role of employers regarding biological hazards?

To ensure safe and healthy workplaces and consult with workers' representatives.

What is the responsibility of workers under the new biological hazard standards?

To engage in implementation and monitoring.

What historical role do trade unions play in workplace safety?

They ensure workplace safety and health by organizing, campaigning, and lobbying for standards.

What does the new standard aim to address beyond pandemics?

Infectious diseases from work exposure, toxins, allergens, and venoms affecting outdoor workers.

What is a key benefit of the new standards for biological hazards?

It fills a normative gap in addressing biological hazards.

What does the guidance from the new standards cover?

Protecting vulnerable groups and encouraging risk assessments in high-risk occupations.

What are the key actions for the labor movement in response to infectious disease outbreaks?

Organizing, lobbying, preparedness, preventing risk to frontline workers, and ensuring all workers, including health workers, are protected.

What is the first message to workers in the global context regarding labor rights?

Secure freedom of association, right to organize, and collective bargaining.

What should informal and precarious workers do to address their challenges?

Communicate and recognize shared challenges, form collective organizations, and demand that protections for directly employed workers also apply to them.

What historical event caused approximately 1 million deaths and over 1 million emigrations due to famine?

The 1845 Irish Potato Famine.

What are pesticides and their primary purpose?

Manmade chemicals controlling insects, weeds, fungi, rodents, and bacteria, essential for modern food systems.

What ancient practices were used for pest control before modern pesticides?

Burning crops post-harvest and using predatory insects.

What significant achievement did Paul Hermann Müller accomplish in 1948?

He won the Nobel Prize for DDT, a powerful insect control chemical.

What were some problems associated with the use of DDT?

Insect resistance, harm to birds, water pollution, and long-term human health risks.

What is the phenomenon of resistance evolution in pests?

Pesticides kill susceptible pests, leaving resistant survivors, leading to 'super bugs'.

What are some environmental and health risks associated with pesticide use?

Soil and water pollution, harm to wildlife, and possible human health impacts.

Why do we still use pesticides despite their controversies?

They are effective against major crop threats and mosquito-borne diseases and are regulated by strict safety standards.

What are some nature-inspired methods for pest control mentioned in the notes?

Using plant/fungal chemicals to repel or attract pests and beneficial insects as crop protectors.

What is Integrated Pest Management (IPM)?

A strategy combining knowledge from multiple disciplines to make effective and responsible pest control decisions.

What are the two main steps in Integrated Pest Management (IPM)?

1. Gather information using computer tools and field guides. 2. Field scouting to observe crops closely.

What is the goal of managing Soybean Cyst Nematode (SCN)?

To keep SCN population low or prevent field infestation.

What are some management strategies for Soybean Cyst Nematode (SCN)?

Plant SCN-resistant soybean varieties, rotate to non-host crops, and use seed treatments to deter nematodes.

What factors should be considered in economic and environmental considerations for pest management?

Cost of management strategies, level of pest infestation, and environmental impact.

What is the global annual use of pesticides?

Over 5 billion pounds.

What are the benefits of high-tech solutions in pest management?

Drones with sensors/GPS for targeted pesticide application reduce environmental impact.

What is the long-term goal for pest management solutions?

To blend natural methods, technological precision, and reduced chemical reliance.

What was one of the early chemical treatments for pest control?

Arsenic, lead, and copper.

What is the significance of the 1972 ban on DDT in the U.S.?

It was banned due to its harmful effects, but residues persist today.

What does the convention regarding labor rights state about informal workers?

It applies to all workers, and governments must recognize and protect their rights under international labor and human rights frameworks.

What does IPM stand for and what does it involve?

IPM stands for Integrated Pest Management, which involves informed decision-making using science, field observation, and cost-benefit analysis, combining prevention, monitoring, and targeted control to protect crops effectively and sustainably.

What are the major crop pests and the problems they cause?

Major crop pests include weeds, insects, and diseases. They increase land maintenance, restrict water flow, raise costs and labor for growers, and lower crop yields.

Why was IPM developed?

IPM was developed due to increasing pest numbers caused by selection pressure from pesticides and natural selection.

What is the definition of IPM?

IPM is a systems approach that integrates practices considering economic, ecological, and sociological impacts.

What are the risks of over-reliance on one tactic in pest management?

Risks include mechanical overuse leading to issues like the Dust Bowl and chemical overuse resulting in herbicide resistance.

What are the four pillars of IPM?

The four pillars of IPM are: Mechanical (mowing, tilling), Cultural (crop variety, planting date), Biological (using organisms to reduce pest impact), and Chemical (pesticides like herbicides, insecticides, fungicides).

What are the steps to effective IPM?

The steps include identifying pests, surveying the area to assess infestation levels, evaluating risks and benefits of available tactics, and selecting effective, safe, and environmentally responsible tactics.

What are the long-term goals of IPM?

The long-term goals of IPM are to reduce annual crop losses, gradually lower pest numbers over time, and create a sustainable crop production system.

What is a GMO?

A GMO is any plant, animal, or microbe with altered DNA, commonly including engineered bacteria for insulin, vaccines, and cheese.

How many hectares of GM crops are grown worldwide and in how many countries?

GM crops are grown on approximately 185 million hectares in 26 countries, including 19 developing nations.

What are some common GM crops?

Common GM crops include soybean, corn, cotton, alfalfa, canola, apples, papaya, potatoes, squash, sugar beets, and pineapple.

What are the limitations of traditional plant breeding?

Limitations include only transferring genes between closely related species, introducing many unknown genes causing undesirable traits, and taking many years for slow-growing crops.

What is the difference between cisgenics and transgenics in genetic engineering?

Cisgenics involves gene transfer within the same species, while transgenics involves gene transfer across species.

What is the process for making GM crops, such as Bt corn?

The process includes identifying the desired trait and gene, copying the gene, inserting it into plant DNA using a vector or gene gun, and then growing transformed plants.

What is the role of Agrobacterium in genetic engineering?

Agrobacterium naturally inserts DNA into plants via its Ti plasmid, which is modified by scientists to carry desired genes.

What is the regulatory process for new GM plants?

New GM plants undergo rigorous testing for gene insertion accuracy, trait effectiveness, and safety, requiring data proving no allergenic risks and nutritional equivalence.

Which US agencies are involved in the regulatory approval of GM crops?

The US agencies involved include the EPA, USDA, FDA, and APHIS.

What are some typical uses of GM crops?

Typical uses include virus-resistant papaya, crops producing bacterial toxins to kill pests, and herbicide-resistant crops for selective weed killing.

How do GM foods compare nutritionally to traditional varieties?

GM foods are nutritionally equivalent to traditional varieties unless engineered for enhanced nutrition, such as Golden Rice with a vitamin A precursor.

What is the commercial history of GM crops?

GM crops have been used commercially for nearly 30 years without credible evidence of harm to humans or animals.

What evidence exists regarding the safety of GM crops used commercially for nearly 30 years?

There is no credible evidence of harm to humans or animals.

What are some ongoing concerns associated with GM crops?

Health and environmental safety, social and economic issues (especially corporate control over seeds and agriculture), and sustainable food systems amid climate change challenges.

What caused Minamata Disease?

Methyl mercury pollution from the Chisso Chemical Corporation entered Minamata Bay, bioaccumulated in fish, and caused neurological disorders in over 2000 people.

What are the two types of diseases impacting humans?

Chronic (long-developing) and acute (rapid onset) diseases.

What are some causes of diseases impacting human health?

Pathogens (e.g., Ebola virus), risks from behaviors (e.g., smoking), and pollution (toxic chemicals in the environment).

What are the five categories of toxic chemicals?

Neurotoxins, carcinogens, teratogens, endocrine disruptors, and allergens.

What is an example of a neurotoxin?

Methyl mercury or lead.

What is a carcinogen and give an example?

A substance that causes cancer; for example, asbestos causes lung cancer.

What do teratogens do and provide an example?

They cause birth defects; for example, thalidomide or alcohol causing fetal alcohol syndrome.

What are endocrine disruptors?

Chemicals that interfere with hormones by blocking or mimicking them, such as DDT.

What does the Stockholm Convention aim to do?

It bans harmful endocrine disruptors and has identified a 'dirty dozen' chemicals.

What is the LD50 test?

A test that determines the lethal dose for 50% of test animals, used to estimate safe exposure limits for humans.

What is bioaccumulation?

The accumulation of toxins in organisms, which increases in concentration up the food chain.

What is biomagnification?

The increase in toxin levels as they move up the food chain, affecting larger predatory fish and humans.

What are the three main routes of chemical entry into the body?

Gastrointestinal tract (ingestion), respiratory system (inhalation), and skin (dermal absorption).

How are most chemicals ingested absorbed in the body?

Most are absorbed in the small intestine through passive diffusion, facilitated diffusion, or active transport.

What role does the liver play in chemical absorption?

The liver metabolizes chemicals, making them less or sometimes more toxic.

How do chemicals enter the bloodstream after absorption?

Once absorbed, chemicals enter the bloodstream and can be distributed throughout the body.

What barriers protect sensitive tissues from chemicals?

The blood-brain barrier and placental barrier.

How do chemicals distribute in the body?

Chemicals move from blood into the fluid between cells via capillary filtration, influenced by blood perfusion rates.

What happens to stored chemicals in the body?

Stored chemicals may re-enter the bloodstream under certain conditions, such as pregnancy or lactation.

What is the significance of the skin in chemical absorption?

The skin provides a barrier to chemical absorption, allowing only the most lipid-soluble chemicals to penetrate.

What are the health impacts of pollution as highlighted in the notes?

Pollution can lead to diseases caused by toxic chemicals in the environment.

What are the primary organs responsible for the excretion of chemicals from the body?

Kidneys (urine), digestive tract (feces), lungs (exhaled air), and secretions (saliva, sweat, breast milk, hair, nails).

What is human biomonitoring (HBM)?

The use of levels of chemicals or their metabolites in blood and cord blood as biomarkers of exposure.

What does toxicodynamics study?

How toxic substances impact living organisms at cellular and molecular levels.

Why is understanding the mechanism of action of toxins important?

It helps predict the outcomes and severity of toxic effects and aids in creating antidotes, therapies, and regulations.

What is the dose-response relationship?

The correlation between the dose of a toxin and the organism's response, where typically higher doses cause more severe effects.

What factors influence the response to toxins?

Individual susceptibility, genetic differences, and environmental conditions.

What is the difference between acute and chronic exposure?

Acute exposure is short-term and high-dose, while chronic exposure is long-term and low-dose.

What are some advances in toxicodynamics research?

Technologies like high-throughput screening and advanced computational methods that analyze large data on toxins and their effects.

What is Environmental Risk Assessment (ERA)?

A systematic process to identify, evaluate, and quantify risks from environmental hazards.

What types of risks are identified in Environmental Risk Assessment?

Health risk (likelihood of adverse health effects) and hazard risk (risk of incidents like chemical explosions).

What are the components of risk in ERA?

Probability (likelihood of an event) and consequence (severity of the event's impact).