Environmental Health: Definition and Key Factors

• Course: HSCI 204 Perspectives on Human Health + Environment

Important Dates

• Question set 1: Feb 9
• Midterm: Feb 27
• Question set 2: Mar 30
• Textbook: Essentials of Environmental Health (Robert H. Friis), available on Canvas
• Office hours: Thursdays, 10:30-12:30, Allan Blusson Hall 11504 (Dr. Lanphear by appointment)
• Assignments are due every Sunday night.

What is the Environment? What is Environmental Health?

• Environmental health encompasses all links, both positive and negative between the environment and human health
• Environmental health includes the quality of life determined by physical, chemical, biological, social, and psychosocial environmental factors
• It involves assessing, correcting, and preventing environmental factors that can affect the health of present and future generations. (WHO definition)
• Key ideas:
  • Broad encompassing definition of "environment."
  • Environmental health determinants are modifiable, aiming to minimize damage and maximize environmental benefits

Environmental Health Science

• It is an academic field
• It is an area of research
• It includes areas of applied public health practice.

Planetary Health

• It explicitly accounts for the role of natural systems in averted disease cases + potential harm from human-caused perturbations
• Both planetary and environmental health examine the relationship between human health and conditions and exposures originating outside the body.
• Accumulation of small effects leads to enormous impacts on the population.

Key Ideas + Recurring Themes in Environmental Health

• Environmental hazards are "upstream" forces.
• Environmental exposures contribute to morbidity and mortality, but the role can be overlooked and difficult to quantify
• An individual’s exposure to environmental health determinants depends on their location
• The type and importance of hazards depends on the level of development ("The environmental risk transition")
• "Where" to intervene is determined by the "hierarchy of exposure controls."
• Population growth and urbanization: More than half of the world's population lives in urban environments. Urban centers are predicted to grow, while rural populations remain stable
• There's a shift in environmental burdens from local to global concerns (e.g., household sanitation to greenhouse gas emissions).
• There is another transition involving time scale: a shift from immediate health impacts to delayed impacts over months/years/centuries

Hierarchy of Controls

• PPE not always useful; involves changing behaviours which most people do not like
• Eliminating the hazard is the best intervention

Themes in HSCI 204

• Issues in high-income versus low- and middle-income settings.
• Trade-offs.
• Many environmental hazards are byproducts of activities that benefit society.
• Unconscious actions contribute to environmental health
• Environmental and occupational health involve more than just "pollution."
• Occupational injuries, access to green spaces, and food safety are relevant.

The Origins of Environmental Health

• Hazards are usually identified first in workers, then in communities.
• Most chronic diseases are man-made; most things that kill are designed or brought upon humans.
• Environmental impacts are more significant than genetic factors.
• Identifying and controlling environmental hazards are key to prevention.
• Studying the past informs intervention on new threats using past solutions, improves patient medical care, understands disease burden trends, and identifies root causes to prevent disease.
• Hippocrates: To understand population health, examine their air, water, and living places.

Epidemiologic Transition

• A theory describing the shift in disease patterns and health outcomes as societies develop (proposed by Abdel Omran in 1971)
• Outlines the changes in population health associated with economic development and demographic changes:
  • The age of pestilence and famine
    • High mortality, low life expectancy, fluctuating population size.
    • Deaths are caused by infectious diseases, malnutrition, and famine.
    • Predominantly pre-industrial societies with limited medical knowledge and poor sanitation.
  • The age of receding pandemics
    • Declining mortality, increasing life expectancy, and population growth.
    • Reduced infectious disease impact due to improved sanitation, public health, and medical advances.
    • Industrialization, urbanization, and better food supply contribute to better health
  • The age of man-made diseases
    • Further decline in mortality, longer life expectancy, stable population growth.
    • Deaths are caused by chronic and degenerative diseases and lifestyle factors.
    • Continued medical advances, but lifestyle changes lead to new health challenges.
• Bernardini Ramazzini: diseases of workers; noticed the environment impact on human health
• John Evelyn: Recognized London's smoke, noting both the negative impacts and positive conditions in areas with better air quality.
• Early England used coal once the forests were depleted, contributing to the Industrial Revolution.
• The first environmental carcinogen: Soot, black carbon smoke, recognized by Percival Pott (scrotum growths).
• The Urban Penalty: People moving from rural areas to cities faced inadequate housing, sewage, and water
  • 35% higher infant mortality.
  • Dense & dangerous infrastructure (up to 14 stories high).
  • Rampant TB cases, the leading cause of death.
  • Scrofula: Slow growing meningitis that grows into the brain.
• Population increased as children stopped dying.
  • Arthur Newsholme researched reduction of phthisis (TB).
  • People getting medical care in institutions found higher death rates, compared to those treated at home.
• Vitamin D not a true vitamin, because the body can produce it: Children in massive infrastructures suffered due to lack of sun exposure and were at a higher risk of contracting TB

First Industrial City

• Labour deaths were caused by asbestos fibers in mills causing lung cancers.
• Asbestos: Even after ending domestic production, people still die due to the latency period

Summer Diarrhea

• Death of cholera patients and circulatory collapse.
• Occurred in babies who had been formula fed versus breast feeding
• "Formula" was cow's milk diluted with water, lacking adequate nutrition.
• This led to absence of vitamin A and exposure of pathogens in the food given (fake formula)
• Circulatory collapse was exaggerated in hot weather leading to deaths.
• Dr. John Snow tracked people to determine how cholera spread.
  • Discovered various pumps were contaminated while others weren’t .
  • Water brought from underneath London was interconnected with the sewage system

Joseph Bazalgette

• He was given the authority to construct the enormous sewer system which he designed
• People complained about the smell for years before project approval
• This led to water sanitization and chlorine.

Epidemiologic Triangle

• Wade Hampton Frost
• A microbe capable of causing infection and disease
• A host population with enough susceptible people
• Environmental conditions to bring the agent into contact with infectible hosts

Lung Cancer Epidemic

• Dr. Alton Ocshner was the first anti-smoking crusader.
• He watched lung cancer become a massive concern, but it moved slowly thus people weren’t too worried.
• Conducted smoking survey to determine correlation between smoking and lung health.
• Physicians Smoking Study: Case control study. debated the cigarette as an environmental/genetic factor.

Synergistic Effect

• When the combined effect of two risk factors or toxins is greater than the sum of their singular effects.
• Combining asbestos and smoking.
• A ban on smoking in public places in Scotland saw a 15% reduction in preterm births.
• 80% of tobacco-related deaths will occur in industrializing countries.
• Current solutions don't address upstream risk factors; build more beds in health care systems

Association or Causation

• Austin Bradford Hill's criteria: Randomized control trials aren’t always representatives

Criteria for Causation

• Strength and consistency of the association between exposure and outcome plus specificity, temporality, biologic gradient, plausibility, coherence, experiment, and analogy.
• Small association effects compound to impact a larger population.
• Pima People have a genetic stock from Mexico and New Mexico
• US Pima people were found to have similar rates of diabetes to rest of the US
• Within 70 years, ½ US Pima peoples were diagnosed with diabetes.
• They lost their water supply due to people taking the water from river upstream of them. The government gave them surplus of food to support, but food was not healthy and diabete rates increased significantly.
• Doctors assumed genetic issues when this was not the case at all. PFOA chemical: Found in gortex, and pizza boxes to prevent staining.

“Forever Chemicals”

• They can't be broken down and are very carcinogenic.
• Lower exposure to PFOA chem leads to lower rates of diabetes. Lead Content Levels in Blood:
• When young women menstruate, blood levels drop.
• Scientists did not note this change for a long time accounting for gender differences in lead levels.

Dr. Marie Curie

• Nobel Prize winner: She studied radium girls (watch face painters) with radium, leading to early and painful death, increased risk of bone sarcoma and cancer in the face.
• The production company always blamed the issue on “poor dental hygiene”.

Minamata Disease

• Mercury poisoning.
• A plant in Japan dumped mercury into the ocean.
• Fish uptook mercury and humans would eat it.

Mercury Poisoning

• There are very few people living over 60 years old in Canada.
• Silent Spring (Rachel Carson): Discussed substances in bodies, although measured in ppm or ppb, noted that they were significant in the body. DES hormone - synthetic estrogen:
• It produced carcinoma, increased breast cancer, and infertility.
• DES was banned but still used in cattle feeding. Potency unsure, but still exposure to humans.
• Mice Image - one fat one small: Same genetic, caloric intake, and activity level, but one exposed to 1 ppb DES in utero exposure.
• 6 trillion dollars spent on lead poison deaths per year
• HIV/AIDS kills 1 million people a year; lead poisoning kills 5 Million, resulting in finance discrepancies.

Week 2 - The Health Impact of Environmental Hazards

• Consider the large impact of environmental hazards on death and disease + exposure prevalence
• Differences between YLL, YLD, and DALYs
• Epidemiologic transition + environmental risk transition

Pollution Video

– "A global health crisis."

• Pollution kills more people than hunger, war, malaria, and AIDS combined.
• Pollution is seen as an environmental issue, not a health issue.
• Much of pollution goes under the radar because it is not as significantly visible: Reminder week one:
• Enormous prevention: cumulative impacts on all populations.
• Small effect: risk posed to any individual or exposed person is small.
• Anyone who is exposed, increases the risk of illness/disease only increases a little bit.

Upstream Forces

• Much of environmental health is determined by “upstream forces” that seem at first glance to have little to do with environment or health.
• Health starts in our community and homes, not only within a doctor’s office.
• Rather than waiting until people get sick, determine the cause and root to prevent it. Occasionally, the link between enviro and human health is obvious + the time scale is very short.

Major causes of death: heart disease, stroke, pulmonary, and lower respiratory what is the chart missing? what info is it lacking to tell us? Chart doesn't tell WHEN are people dying. There is MORE to health than avoiding death. It doesn't tell us what is “upstream” of these causes. quantifying health: how many people die of _____? (doesn't account for WHEN) how many people die of _____ AND at what age do they die? (doesn't consider illnesses or disabilites that DONT lead to death) "How many people die of _____, at what age do they die, and how long are they disabled by _____ and how severe is that disability?" + How long do they live at less than full health?

DISABILITY-ADJUSTED LIFE YEAR (DALY)

• It is a combo of dying prematurely or living at less than 100% health. DALY = YLL (dying early) + YLD (living less than ideal health) = “one lost year of healthy life”.

Years of Life Lost (YLL)

• Take the years between death and life expectancy

Years Lost Due to Disability (YLD)

• "Years lost" to disability is a function of time lived WITH the disability and its severity, alive but not living to 100%.

The Global Burden of Disease (GBD)

• Provides a tool to quantify health loss from hundreds of diseases, injuries, and risk factors
• Useful source of info on upstream contributors (risk factors) and downstream contributions (causes) to death and disease
• Population Attributal Fraction is the proportion of cases of disease that can be attributed to a specific risk factor; it estimates how much the disease burden would be reduced if the risk factor were eliminated.

To estimate the number of deaths or DALYs linked to a risk factor, you need:

• Exposure: How many people are exposed? How much are they exposed to?
• Exposure-response relationship: How does health risk change as exposure changes?
• Counterfactual: What is the alternative scenario?
• Burden estimate for the outcome: How many total deaths or DALYs are caused by the disease?

Prevention Paradox

• “…a large number of people at a small risk may give rise to more cases of disease than the small number who are at a high risk.”

The Prevention Paradox Scenario 1

• High-Risk, Lower Exposure Prevalence: Hazard is much riskier. 10% of the population is exposed.
• Risk: 25% of exposed individuals develop the disease, resulting in 2.5% of the total population cases.

Air Pollution Stats

• 8.1 million deaths per year
• Second leading cause of death
• Leading cause of DALYs
• ⅓ lower respiratory infections in Africa/Asia
• Responsible for 48% of deaths from chronic obstructive pulmonary disease “a large number of people at a small risk...”

Problems w GBD

• Many exposure/outcomes pairing not yet included but probably should be.
• Uncertainties in exposure assessments and concentration-response relationships.
• Limitations of including climate change:
  • Many indirect pathways may lead to climate change and health issues, but GBD isn't set up to quantify
  • Categorizing a disease or disorder AND disability weights.
  • Difficulty in quantifying severity of disabilities AND how to COMPARE disabilitys (ex. hearing loss vs losing a leg).

Week 2 Part 2: Rose’s Radical Ideas

“It is better to be healthy than ill or dead. That is the beginning and the end of the only real argument for preventive medicine. It is sufficient.” Geoffrey Rose

5% Population Health

• A strategy or approach to health that aims to improve the health of the entire population and reduce health inequities among population groups.
• 95% clinical strategy: physicians diagnose people with signs or symptoms of a disease – preferably early in its course – and prescribe a drug or perform a surgical procedure.
• population strategy: scientists attempt to identify and reduce upstream risk factors in populations that cause disease.

The Platt-Pickering Debate

• Platt believed one was either healthy or sick. Pickering argued hypertension exists on a continuous scale in a population. The higher the pressure, the worse the prognosis
• There can be a range of illness and continuous perspective.
• Jerry Morris examined coronary heart disease causes
• Morris concluded exercise protected people from heart disease.

Roses Ideas

• Video example: combining tobacco and/or lead and the increase in risk of getting ADHD in children

Synergistic Effect

• Combining substances increases outcomes compared to only one risk factor.

Individuals or Populations

• “A large number of people at a small risk give rise to more cases of disease than the small number who are at a high risk.”
• More babies born to younger women, so more cases will be present there, might initially think the risk is much higher in the older women, but consider others factors influencing outcome.

Triggers of Heart Attacks

• Cocaine puts a small number of people at a high risk of having a heart attack (MORE likely to cause heart attack BUT LESS PEOPLE DO IT).
• Air pollution puts a large number of people at a small risk of having a heart attack (everyone is exposed but it is less likely to directly result in heart attack).
• Iceberg Phenomenon: Most of the disease process is unseen, only the tip of the iceberg is apparent lowering population average shrinks the prevalence.
• Focus on exposures spread across large populations + protect the few, protect the MANY.

Ancel Keys

• Gave: “If we wish to find the explanation, it will not come from studying individuals but rather from seeking some community-wide factor.” insights to causes of disease, focused on population-level factors.
• Developed military meals but included cigs, later on he was responsible for promoting the mediterranean diet: the ultimate diet.

Biology and Health "There is no known biological reason why every population should not be as healthy as the best.” Example is that some groups have hypertension blood pressure and others don’t, there is no NORMAL/BIOLOGICAL reason why certain groups would have poor blood pressure.

Risk Factors of CHD (Coronary Heart Disease)

• Sex, obesity, smoking, diabetes, salt intake, physical activity, genetic components, air particles (PM2.5), toxic metals (lead)

Endothelial Dysfunction

• Cells are exposed to lead.

GBD for Lead

• Annual deaths: 5.5 million
• Annual cost: US$ 4.6 trillion
• Contributes to 5.3% global GDP and 7.8% LMIC GDP.
• Estrogen is linked to protecting women from CHD. Estrogen drives lead into bones and each month the body sheds some lead due to menstruation. In menopause, there is a 30% increase in lead in women due to bone breakdown.
• Lead removal from gasoline decreased CHD.
• CHD was a result of exposure to RISK FACTORS (lead) IT WAS PREVENTABLE AND NO INEVITABLE. There was push back on inhibiting lead use. Tax dollars were paid and industries had no consequences. Scotland Smoking Ban: A 20% reduction in heart attacks due to reduced second-hand smoke.

Precautionary Principle

• “Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.”
• “When an activity raises threats of harm to human health or environment, precautionary measures should be taken even if a cause-and-effect relationship is not fully established scientifically.”
• Burden of Proof: “When a epidemiologic evidence indicates that a common material may be having serious adverse health effects the burden of proof should shift from those who draw a causal inference, to those who maintain no causal inference is possible.

Conclusions

• Clinical strategies and population strategies are complementary. We are failing to prevent preventable diseases because too much emphasis on clinical strategies.
• There are communicable, maternal, neonatal diseases. Injuries and Non-communicable diseases.

Week 3 - Exposure Assessment and Environmental Epidemiology

• Combine ideas like exposure assessment, epidemiology, toxicology, risk assessment

Exposure Asssessment

• Who is exposed?
• To what?
• To how much?
• When?
• Where?
• How Frequently?

Use of Exposure Information

• Epidemiology assessments
• Surveillance, evaluation of exposure trends
• To identify sources / determinants of exposure
• To compare with regulations / guidelines
• Acute*: short term “burts” of exposure (hours to days) often higher concentrations/doses immediate symptoms
• Chronic*: longer term periods of exposure )years to life time) often lower concentrations/doses, over prolonged times onset of new disease

Exposure Route

• How a substance enters the body
• Human barriers to the environment are skin, respiratory tract, and digestive tract
• Three routes of exposure are:
  • Dermal (skin contact)
  • Inhalation (air particles/pollution)
  • Ingestion (pesticides)
  • Relative importance varies depending on
  • Pollutant + the particular population

Exposure Pathways

• The physical course a pollutant takes from source to subject
• Pollutants move through water (leaching and runoff) and air
• recall hierarchy of controls; solutions higher up in the hierarchy move from most to least effective. Where is the best place to intervene? at the source? along exposure pathway? at household or individual?

What is the best way to rescue exposure to a hazard?

• To produce less of that hazard
• Health impact require estimating exposure
• NHANES US survey of risk assessment to determine exposure associated with health concerns
• Monitor health and risk factors
• Identify exposure sources

Exposure Surveillance and Impact Assessment

• Use both simultaneously to increase the impactfulness of both
• Three KEY IDEAS in exposure assessment:
  • Concentrations vary in time -Temporal variation
  • Concentrations vary from place to place Spatial variation People Move Around

Exposure Variability

• Exposure rates are different between different populations, locations and group
• Health studies require VARIATION in exposure to see if it CORRELATES to variation of health
• The changes that occur in the environment vary over time, ranging from daily cycles to long-term climatic shifts in Temporal variation. Spatial Variation changes from locations.

Exposure Assessment Methods

• They measure individuals by personal measurements and biological markers (“biomarkers”)
• Personal: Can provide a better estimate of true exposure. BUT are expensive and time-consuming.
• Biomarkers measure pollutant or metabolite estimates dose and incorporates multiple exposure e.g. exhaled breath, urine, blood, teeth, hair

Indirect Methods

• Area measurements, questionnaires, models Historical examples for the study designs include Hill and Doll with a questionnaire, Selikoff with Asbestos, Harvard with air pollution .

Environmental Epidemiology

• The study of the distribution and determinants of health related states or event in specified populations, and the application of this study to control of health populations
• Key ideas
  • The fact that A and B are correlated does not necessarily mean that A CAUSES B or that B causes A. Correlation DOES NOT equal causation, experimental designs can provide stronger evidence of causality.

Study Designs

• Observational Designs (common)
• Cross-Sectional: “snap shot” - assess exposure and outcome at a single point in time.
• Case Control: Identify participants based on disease (outcome), then determine who previously had the exposure Cohort: identify participants who do not have the disease of interest, observe them over time to asses new cases of the disease. Advantages:Less susceptible to bias + Temporal relationship between exposure and outcome is known Disadvantages: Rare cases + expensive time series data

Experimental Designs

• Randomized control trial (gold standard?)
• Natural experiments = Data or correlation observed by natural causes, not by researcher manipulation
• Example: Coal sales banned in Dublin
• 15.5% decease in repsiratory deaths + 10.35 decreased in respiratory health data analysis

Effect Estimates

Determining false positives, true positives, false negatives and true negatives. Odds ratio: the ratio of odds in favor of exposure among the cases and the odds in favor of exposure among the non-cases pooled analyses or meta-analyses = “studies of studies”: Needed when one study is insufficient.

• Ubiquity of Exposures = when 100% of the population is exposed to some hazards.

When do we act with suffiecnt evidence? precautionary principle “Where there are threats or permanent damage to our bodies we should act immediately”

• temporal relationship
• strength of association
• dose-response relationship
• replication of findings

Week 4 - Toxicology and Risk Assessment

• Toxin: a compound of natural origin that has adverse effects on biological systems. Toxicant: a SYNTHETIC compound that exerts adverse effect on biological systems

Toxicokinetics: ADME process of toxic substance

• Absorption: Toxicant crosses biological barrier
• Distribution: Toxicant spread within body
• Metabolism: Substances undergo metabolic conversion to make water soluble
• Metabolite may be more toxic than parent compound (eg. methanol)
• Excretion: Urine, feces, exhaled air + breast milk, development of fetus

Toxicity Effects

• Mortality (disease)
• Teratogenicity
• Ability to cause cancer
• Carcinogenicity
• Mutagenicity
• Neurotoxicity

Dimensions of Toxicity

• Toxicant and the ”target organ” Damage due to specific exposure + the dose
• "All substances are poisons… the right dose differentiates a poison from a remedy” Paracelsus – “the dose makes the poison."
• Substances can benefit at lower doses byt toxic at higher doses
• Dose response

Review Non-Nutritive Toxicants

• Safe level or threshold of exposure before health effects come to fruition

• When no threshold, the only “safe”exposure is ZERO

• Linear vs non linear relationships: -Supralinear: Very steep and it plateaus

• Importance of change + how it related to the outcome

• Timing of exposure e.g. Thalidomide exposure

• Quantifying Toxicity The amount (dose) of a chemical which produces death in 50% of a population of test animals to which it is administered + comparing and quantifying the acute toxicity. LOAEL - Lowest observed Adverse Effect Level: how low can we get and still have bad stuff happening. Differences in population occur at the same rates.

Regulatory Toxicology

• Threshold based approach for carcinogen or non-carcinogen

Threshold Based Approach

• Formula: Acceptable daily intake OR reference dose = NOAEL / UFs (margin of safety)
• Pods = When bad things happen

Non-Thresholded Based

“slope factor” or “q*” or carcinogees Take a line of estimation but make it wider/ less accuarate for precaution

Environmental Risk

• Hazard doesnt equal Risk
  • Hazard is when something is capable of causing an effect, but it is not the same as the Risk of something casuing an effect “something can be hazardous, but if there is no exposure, there is no risk”
• Risk Assment +Risk Management
• ATSDR : Gather data for carcinogon or non carcinogen risk assessment
• IARC :classify based on severity

Calculate risk,estimate and analyze info.

Perception of Risk and its many types influence individuals choices and behaviours. Quanititaive and perceived values are used to assess the influence.

WEEK 5 - Air Quality

Historical context

• Evidence of habitual use of fire around 300000-400000 years ago
• Hundreds of years if sporadic attempts to control pollution

Pollutants:

PM Size and Concentration describe the particle and Volume in air. Air pollution has the largest health impact on particle matter. Particulates deposit in sections such as the upper, middle and lower airways. The lower the worse.

Particle Size - Important for size distribution:

• Particulates end up going in all parts of the respiratory tract
• PMs are a result of the many ways humans and animals emit toxins. PM concentrations: Mass of particles in a volume of air

World Health Organization (WHOs) Air Quality Guidlines:

• PM concentrations in Canada are much higher in urban areas
• Ozone is needed to block UV ray in higher density areas
• High concentrations impact the lining in air ways

Burden of Diseases from Ambient Air + The effect of the environment on people

• Particles and mixes result in cardio and respiratory diseases
• Cause specific health impacts PM resulting health issues and diseases Air Quality and Health Reserach such as animal +human controlled exposure
• A combination of factors influences the type of study researchers make

Time Serious

• 1000s of studies show that when pollution goes up, mortality also goes up
• Acute or daily tests show that for small but consistent effects, they can happen very rapidly and in wide distribution.
• Chronic testing also allows scientists a wider data range

Traffic in important sources: Traffic as important source: Its not just which city you live in, but WHERE in city you live. non-morality and lung results are often the case for non carcinagens

• mortality: dead

  • not as common with some diseases or impacts less common, small effects and small change.
  • morbidity: illness.
  • much more commone, larger change and much larger disease/impact.

• ⅓ airborne diseases - 33% are to lower respiratory tract infections Vancouver average 7PM2.5 is common in cities where cars a big contribution .

air pollutuon: air pollution strong risk factor for pre term birth and low birth wight (⅔ due to household aid pollution

• if preterm this is bad in later life as they start to have higher risk

• The UGAAR study - Ulaanbaatar Gestation and Air Pollution Research

Air Quality Management

• You can have economic progression while cutting emissions
• It is beneficial as sick people do not benefit the economy

Household Air Pollution

• Indoor cooking and heating
• Disproportionate exposure of women and children
• "…47% of the world’s population — almost 3.6 billion people — are still exposed to pollution from household use of solid fuels

Global Burden Disease

• High blood pressure, smoking. low weight are often a huge contribution to overall health

Carbon Monoxide

• Comes from everyday activities like cooking. The hemoglobin in our blood cell absorbs CO better
• Hemoglobin suffocates from no oxygen

Week 6 - Pesticides and Human Health

• "Pest" means any destructive animals, plant, or micro-ogranisms

• Peticides kill living thing and are intentionally added to the enviroment

• Pestcides can kill bigs, fungi etc

• Why pests are used (Benifit in near term but not long term)

• Chemical resistense allows organisms to withstand the effects of pestcides

List of Herbicides

• Control by:Contact Vs Systemic, Mode of Action, GM Crops Insecticides can have chemicals from plants such DDT

Rachel Carsons was biologist with a double masters

• Her book exposed DDT harmful effects
• Stockholm convenrtion = treat to protect people
• Organophosphates (OP) responsible for most poisoning

"Organophosphate Insecticides (OP) responsible for most pestcide poisonings and death BUT Carbmates

• Pyrethroids

Synthetic can be used for alllergens

• Neonicotinoids pesticides from soil often effect trees andbees
• Peticide espoure is often dietrary , inhalation and dermal
• Global est. 3-5 million poisonings + 150000 pesticide suicides happen every year.
• Cancer espoures espoucing high concentations Integrated pest is used to monitor physical and chemical systems but is expensive and time consuming Non Glyphosphate used in vacover, only used in golf courses

Pesticides, the benifits of food and its link to toxicity

Farmers often use guano which is rich in nitrogen and help crops grow. Arsenic can lead to lung cancers.

Regretablle subsitutions Insects

Pesticide use is now up for consideration

• Pregnant woman with higher exposure to pesticides Male frogs in genetically male frogs where scientist could find ovaries Often companies strong arm scientist to ensure they dont ruin there company which is what happened ti Dr Tyronaes Hayes

Explore the definition of environmental health, encompassing the links between the environment and human well-being. Understand how physical, chemical, biological, social, and psychosocial factors play a role. Learn about assessing and preventing environmental factors that impact current and future generations health.