FMPH 130

Waterborne diseases

*B=Bacterium, H=Helminth, P=Protozoon, V=Virus Diarrhea and dysentaaries: - Ameobicdysentery (P) - Balantidiasis(P) - Cholera (B) - Cryptosporidiosis (P) - Giardias(P) - Rotovirus(V) - Salmonella Enteric fevers - Typhoid (B) India and Nigeria highest, Niger and Kenya lowest

Multiple ways to frame environmental health topics

- By type of hazards: Chemical Biological Physical Psychosocial - By sources of hazards (agents): Air pollutants Water Contaminants Food contaminants Solid Waste, Soils Neighborhood - By type of health effects: Respiratory Infectious Disease Cardiovascular Reproductive health Cancer Neurocognitive

Why is environmental health important and what are some of the topics we will cover?

- Environmental exposure is a major cause of disease, death, and disability in countries around the world. - Specific types of pollution, the routes of exposure, the specific toxicants, and the resulting patterns of disease vary greatly from country to country

Environmental determinants of health

1. Natural environment: plants, weather, or climate change 2. Built environment: buildings or transportation 3. Exposure to toxic substances and other physical hazards 4. Physical barriers, especially for people with disabilities An estimated 12.6 million deaths each year are attributable to unhealthy environments - nearly one in four of total global deaths. Environmental risk factors, such as air, water and soil pollution, chemical exposures, climate change and ultraviolet radiation, contribute to more than 100 diseases and injuries. (WHO, 2017) Social determinants of health (Economic stability, Neighborhood and physical environment, education, food, community and social context, health care system) => Health outcomes (Mortality, Morbidity, Life expectancy, Healthcare expenditures, Health status, functional limitations)

Ecosystem Health <=> Human Health (DDT Example)

1874: DDT first synthesized 1939: insecticidal action discovered World War II: controlled malaria 1945: Available for sale in USA 1955: WHO commences a program to eradicate malaria, relies mainly on DDT 1962: Publication of Silent Spring •pesticides detrimental effects on environment 1963: President's Science Advisory committee 1972: EPA bans use of DDT202005: DDT toxicological evidence shows endocrine disrupting properties; possible disruption in semen quality, menstruation, gestational length, and duration of lactation (Lancet Review)

Landmark U.S. Environmental Health Policy

1946: Center for Disease Control (CDC) established 1963: Clean Air Act (PL 88-206) 1970: EPA established 1970: OSHA established 1971: Lead based paint in homes restricted 1972: EPA Bans DDT 1974: Safe Drinking Water Act (PL 93-523) 1980: Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or "Superfund" PL 96-510) 2011: EPA began regulation of "greenhouse gases" (CO2, CH4, N2O, hydrofluorocarbons perfluorocarbons, and sulfur hexafluoride)

Lead: Prevention and Control, USA

1978: the use of lead based paint is banned 1973-1996: Lead phased out as gasoline additive 1991: Safe Drinking Water Act Lead and Copper Rule - requires action when lead levels reach 15 parts per billion (ppb) Environmental Public Health Mission: control hazards, promote health, prevention

Global Environmental Health:

23% of global deaths and 26% of deaths among children under five are due to unhealthy environments. Every year, environmental risks - such as indoor and outdoor air pollution, second-hand smoke, unsafe water, lack of sanitation, and inadequate hygiene -take the lives of 1.7 million children under 5 years (WHO, 2017) Causes of death include: stroke, heart disease, diarrhea and cancers This environmentally mediated disease burden is much higher in lower-income countries

Core functions of environmental public health

3 core public health functions: Assessment: monitoring/surveillance, research Assurance Policy development: - Failures: continued construction of fossil fuel fired power plants despite global warming) - Successes: U.S. Clean Air Act, Toxics Release Inventory, Food Quality Protection Act, - Limitations: many stakeholders, lack of EH experts, vested interests, uncertainty, risk-risk trade-offs

USGS Study estimates 2.1 million people using wells high in arsenic

44.1 million people in the US use water from domestic wells (15% of the population) EPA does not regulate or provide recommended criteria for individual well owners USGA tested 20,450 domestic private wells across the country Developed a logistic regression model of having arsenic> 10 μg/L ("high arsenic")

Lead: Historically

500-312 BC. Lead contaminated Roman water systems and contributed to health problems 1400s: Toxicity recognized 1700s: "Plumbism" recognized 1920s: Alice Hamilton recognized toxicity in workers in smelting, painting, and printing

Tests to measure high levels of arsenic in the body

Blood Fingernails Hair Urine Urine tests are most commonly used in cases of acute exposure All other tests measure long-term exposure (at least six months

CDC: Childhood lead poisoning prevention program (PPP)

CLPPP: the nation's public health leader and resource on strategies, policies, and practices aimed at preventing lead exposure in young children Primary prevention - Removal of lead hazards from the environment - Blood lead screening tests Secondary prevention - supporting state/local programs: blood lead screening - identify high-risk populations

Main contaminants in water

Chemical: - Lead, Arsenic, pesticides, etc.. Biological: - Microbiological - Bacteria (e.g. cholera, salmonella, shigella, E. coli) - Viruses (e.g. Norovirus, Hepatitis A virus...) - Parasites (e.g. helminth (ascariasis (roundworm))) - Protozoal (e.g. cryptosporidium) Infectious diseases caused by biological contaminant are the most common and widespread health risk associated with drinking-water

PFOS/PFOAS/PFAS (Per-and polyfluoroalkyl substances)

Chemicals with waterproof, greaseproof, and non-stick properties - Added to consumer products - Best known: Teflon and Scotchgard Persist in the environment Biomagnification in the food webs PFAS linked to harmful health effects: - including cancer, immune disfunction, developmental and reproductive harm, hormone disruption

Global Children's Environmental Health

Children are particularly vulnerable to environmental exposures - size, behaviors, and stage of development Unsafe water, lack of sanitation and insufficient hygiene (soap and water for handwashing) contribute to - childhood deaths, illnesses, and disability - Impaired growth, neurocognitive development - Endocrine disruption Reducing environmental risks could prevent 1 in 4 deaths of children

Children's Environmental Health

Children are particularly vulnerable to environmental exposures: - size, behaviors, and stage of development Unsafe water, lack of sanitation and insufficient hygiene contribute to: - Childhood deaths, illnesses, and disability - Impaired growth and neuro-cognitive development - Endocrine disruption Reducing environmental risks could prevent 1 in 4 deaths of children

Community and Ecosystem Ecology

Community = assemblage of dependent species Ecosystem ecologists study larger scales of energy, water, nutrient cycling (e.g., food webs) Many essential ecosystem functions (e.g., nutrient cycling) are performed by microbes and invertebrates More species = ecological richness = more ecosystem functions performed

Lecture 1 (Ch. 1): Introduction to Environmental Health

Imagine your home or work place: Is it tranquil or noisy? Is it close to a major thruway/freeway/highway? When was the building built? Is their green space nearby? What are the pipes made out of? Is the water safe to drink? Has it been tested? Are you exposed to chemicals that are hazardous to you and your family? Where does your sewage go? Is it treated? Is it treated and reused for drinking water? Is the kitchen where you eat clean? Is the food safe to eat? Do you live or work close to farms? Do they regularly apply pesticides? What are the agricultural workers exposed to? Do you know of factories, power plants or mining nearby? Are they polluting your air or water? Is there a body of water nearby? Can you swim in it? Do you feel at risk from infectious diseases?

Lead exposure Prevention, USA

Individual prevention: - Houses built before 1978: see paint cracking, chipping, take action - Service lines in homes that are made of lead, should be replaced - Treat lead contaminated water - Change water source: replace contaminated water with uncontaminated water - Blend high contaminated water with low-contaminated water - Install lead removal systems Organizations: - The Alliance for Healthy Homes - Children's Environmental Health Network - U.S. Department of Housing and Urban Development - U.S. Environmental Protection Agency: Lead - National Center for Healthy Housing - National Institute of Environmental Health Sciences

Arsenic: Routes of exposure and risks

Ingestion: - Drinking-water - Food Inhalation - Tobacco: tobacco plants can take up arsenic naturally present in the soil Occupational Health Risks: Processing of glass, pigments, textiles, paper, metal adhesives, wood preservatives and ammunition, hide tanning in pesticides, feed additives and pharmaceuticals

Lead: What are some routes of exposure?

Inhalation - smelting, recycling, stripping leaded paint, and using leaded gasoline or leaded aviation fuel Ingestion - Water (leaded pipes) and food (lead-glazed or lead-soldered containers)

Routes of Exposure to Chemical and Biological Hazards

Inhalation Ingestion Dermal Contact Absorption Injection Epidemiology defines the risk associated with hazardous exposure

Arsenic: Health effects

Inorganic arsenic is a confirmed carcinogen Acute effects: - vomiting, abdominal pain and diarrhea - numbness and tingling of the extremities, muscle cramping and death, in extreme cases.

What is the main reason why randomized clinical trials, the gold standard for evidence in medicine, are not commonly used in environmental and occupational epidemiology?

It would be unethical to randomize participants into exposed and unexposed groups

Toxicity testing and regulatory toxicology

LD50 (dose killing 50% of exposed) is crude, however: outcome (death) unambiguous; comparable across compounds; helps identify lethal chemicals for regulation LD50, NOAEL: used for regulatory decision making Example: EPA calculates a reference dose U.S. laws regulate non-workplace exposures and workplace exposures: 1976 Toxic Substance Control Act: authorizes EPA to regulate chemicals OSHA: Some states have their own stricter laws

Toxicological measure I: The LD50

LD50: Lethal Dose for 50% of the exposed population (median lethal dose) - For acute toxicity - A LD50 is a dose of a toxic chemical that kills half of the test population For chronic toxicity, we refer to Effective Dose (ED50)

Lecture 4: Arsenic, Lead, Vulnerable Populations (Pg. 254-256, 323) Lead

Lead: Key facts Toxic heavy metal found in Earth's crust Generated: - burning fossil fuels, mining, and manufacturing (paint) Lead in the body: distributed to the brain, liver, kidney and bones - stored in the teeth and bones - accumulates over time - measured in blood Lead in bone is released into blood during pregnancy and becomes a source of exposure to the developing fetus There is no known level of lead exposure that is considered safe Lead exposure is preventable

Acute toxicity: Arsenic

Lethal Dose (LD50): the amount of an ingested substance that kills 50 percent of a test sample. It is expressed as mg/kg or milligrams of substance per kilogram of body weight. Animal: Rat LD50: 15 (mg/kg) oral

Hierarchy, Scale & Human Health - Food Webs

Persistent pollutants can bioaccumulate and biomagnify as they move up food webs Bioaccumulation: the accumulation of substances, such as pesticides, or other chemicals in an organism Biomagnification: The increasing concentration of a substance, such as a toxic chemical, in the tissues of tolerant organisms at successively higher levels as you move up the food chain

Prevalence and Incidence

Prevalence - The proportion of people who have the disease (existing cases plus new cases) over the total population for a given time period Incidence - The rate or probability of occurrence of new cases of disease - Numerator = number of new cases - Denominator = population at risk of becoming a new case (changes over time) - Specified over a specific time period

Lead: Sources of exposure

Primary sources 1. Lead paint or dust 2. Drinking water (lead pipes, solder, brass fixtures, or valves) Other sources - Leaded gasoline - home health remedies (azarcon and greta) - imported candies; toys and toy jewelry - imported cosmetics - pottery and ceramics - consumer products, tea kettles and vinyl miniblinds

Limits to growth and the nine planetary boundaries

Proposed safe operating scale is the blackline. Hence, the largest current issues to limit of growth are rate of biodiversity loss and nitrogen cycle... Rate of biodiversity Nitrogen cycle Climate change Stratospheric ozone depletion Ocean acidification Change in land use Phosphorus use Fresh water use Chemical pollution Atmospheric aerosol loading

Dose-response relationship

Quantitative description of association between a compound's exposure and its toxic effects Can be influenced by timing and exposure route

Environmental Public Health: Sustainable Development

Sustainable development is "development that meets the needs of the present without compromising the ability of future generations to meet their own needs" - BrundtlandReport, Our Common Future, 1987 1. To pursue sustainability is to create and maintain the conditions under which humans and nature can exist in productive harmony to support present and future generations" (USEPA). 2. the ability to function without depleting or damaging the things relevant to human health and well-being." Frumkin (pg 59): " 3. Intergenerational equity I (total impact) = P (Population) x A (Affluence) x T (Technology)

Important concepts in toxicology

The dose makes the poison: - very low doses generally do not cause acute adverse health effects Duration of exposure: - the length of exposure is important in understanding health effects Chronic adverse health effects: - such as carcinogenesis or developmental toxicity, create more challenges for defining "safe" doses in humans

Environmental Health:

The field of public health that addresses physical, chemical, biological, social, and psychosocial factors in the environment. It aims to control and prevent environmental hazards

Arsenic case study: Bangladesh

The highest population exposed to high As concentrations is reported in Bangladesh (77 million): - Arsenic levels in groundwater - 2000 μg/L (1ppm) As in Bangladesh 1970s: shallow hand pumped wells built by UNICEF and donor agencies

Across the life course:

The importance of cumulative effects and susceptible periods Accumulation of positive and negative effects on health and wellbeing (trying to prevent this)

Lead: Health effects

The neurological and behavioral effects of lead are irreversible and well known Others: high blood pressure, heart disease, kidney disease, and reduced fertility, mental retardation and behavioral disorders, reduce intelligence, anemia

Biological contaminants: fecal contamination

The principal risk to human health from drinking water: fecal contamination

Sixth Mass Extinction

Today: Scientists agree that we are experiencing a sixth mass extinction of plants and animals Scientists estimate we're now losing species at 100 times the "normal rate," and is not a consequence of evolution Drivers of change: Overharvesting Agricultural activity Urban development Invasion and disease Pollution System modification Climate change Human disturbance Transportation Energy production

WaSH Disease Transmission and Prevention: The "F" diagram

Toilet barrier Safe water barrier Hygiene barrier

Toxicant qualifications

Toxic compound are categorized in three major ways: 1. Chemical class: Ex. heavy metal, alcohols, solvents 2. Source of exposure: Ex. industrial pollutants, waterborne toxicants, pesticides. Identify the source of the pollutant 3. Effects on human health: organ system on which the effects are most pronounced. Ex. neurotoxic effect the nervous system, genetic toxicants, endocrine disrupters

Toxicokinetics & Toxicodynamics

Toxicokinetics is the description of how a toxicant will enter the body and what happens to it once it is in the body Key steps in toxicokinetics: In => 1. Absorption - chemicals gaining access to the inside of the body 2. Distribution - chemicals moving within your body to various organs 3. Metabolism - chemical processing facilitate elimination 4. Excretion - elimination from the body via urine, feces, exhaled breath => out Each of these steps influences can impact the toxicity of the chemical Toxicodynamics: describes the interactions of a toxicant with a biological target and its biological effects.

Lecture 3: Toxicology and environmental epidemiology (Ch. 4, 6) Toxicology definitions

Toxicology: is the study of harmful effects of chemicals (natural or man-made substances) on biological systems Toxins: chemicals of natural origin (from toxinos (Greek)), 'poison' Toxicant: chemical from synthetic processes Toxicity: all chemicals are potentially toxic (pesticides) Paracelsus (1493-1541) The Father of Modern Toxicology: "All substances are poisons; there is none that is not a poison. The right dose differentiates a poison and a remedy"

How do we explain population growth, poverty and life expectancy trends in the face of the depletion of ecosystem services?

Human well being is dependent on food services, which are increasing Technology and infrastructure increase the efficiency with which humanity can exploit ecosystem services Time lags may exist Certain groups/populations are unequally effected and bear the burden

Toxicology to environmental health: challenges

Hundreds of chemistries, thousands of product formulations => Relative shortage of human data and need to extrapolate from toxicology studies => Many potential exposure scenarios globally

Actions that environmental health teams can take:

Identify the mechanisms and the burden of disease Understand which populations are vulnerable and why Describe interactions with other determinants of health Work towards policies that can be implemented

IARC (International Agency for Research on Cancer) Classification of carcinogens

Group 1: - Confirmed carcinogen Group 2: - 2A - Probable carcinogen - 2B - Possible carcinogen Group 3: - Not classifiable Group 4: - Probably not carcinogenic

Types of environmental hazards

Hazard: Sources of potential adverse effects Environmental health hazards include: Chemical agents - lead, mercury, asbestos Physical agents - including noise, heat, radiation, UV radiation) Biological agents - viruses, bacteria, infectious pathogens Social and psychological stressors

Lecture 5: Water quality and global water, sanitation, and hygiene (Ch. 16) WaSH: Water, Sanitation, and Hygiene

1 in 3 people or 2.2 billion people around the world lack safe drinking water. Over half of the global population or 4.2 billion people lack safe sanitation. 2 out of 5 people or 3 billion people around the world lack basic hand-washing facilities at home. In low-income countries, diarrheal disease from inadequate WaSH is a leading cause of death for children.

Drinking water sources of pollution: Anthropogenic & natural

1. Chemical contaminants: - Naturally occurring (e.g. arsenic) or manmade - Discharged from point and nonpoint sources - Nutrients (Nitrates or Phosphates): eutrophication 2.Radiological contaminants: - chemical elements with unbalance number of protons or neutrons 3.Biological contaminants: - bacteria, viruses, protozoa, fungi, parasites; from many sources including human or animal waste Infectious diseases caused by which contaminant are the most common widespread health risk associated with drinking water

What influences the extent of damage?

1. Dose of toxicant - Actual amount of toxicant that enters the body - (Measured as mg/kg mg of chemical/kg of body weight) 2. Route of exposure - the major routes of exposure (dermal, ingestion, inhalation) 3. Duration, timing and frequency of exposure: - acute versus chronic; time of life* 4. The properties of the toxicant 5.Individual factors

Individual factors affecting intoxication

Age: - Cumulative effect - Reduction of the immune function in the elderly Gender: - Pregnancy alters immune system and liver function - Social representations of some occupations Weight: - individuals with more adipose (fat) tissue can retain more lipophilic (fat-loving) chemicals like DDT (i.e. Silent Spring's central character) Other exposures: - Socio-economical status - Other determinants of health such as sedentary behaviors or physical activity - Cumulative exposure at home and at work: e.g. Lead

Established occupational, environmental carcinogens (IARC Category 1)

Agent: Arsenic Sources: Smelters, mines, drinking water Cancer sites: Lung, skin, bladder

Environmental Health Risks (Hazards and Agents):

Air Pollution Unsafe water and sanitation services Infectious Disease (Zoonotic diseases) Pesticides Lead, Arsenic, Mercury Environmental Justice Environmental and Occupational Cancers

Environmental Health Risks for Children Under 5:

Air pollution (indoor and outdoor) Diarrheal Disease Parasitic and vector disease Neonatal conditions

Summary

Applying ecological principles to public health helps us see how humans as nested within ecosystems Understanding ecosystem-human interactions enhances capacity to tackle health challenges Conceptual frameworks (e.g., Planetary health) use systems thinking to describe complexity, emergent properties, feedback Ecological literacy essential for environmental health

Case study: Flint Michigan

April 2014: Change of water supply from Lake Huron to Flint River Lake Huron - Detroit Water and Sewage Department => High chloride to sulfate ratio and no corrosion inhibitor in Flint River compared to the Lake Huron supply => Flint River Distribution System -10-80% have lead service lines

Today, Environmental Health Figures

Are more likely to be teams of experts working for specific agencies and organizations or federal agencies Silence or ineffective communication on important matters of public health can be poisonous to the practice of public health. Prevention is the central thesis of public health practice, findings from laboratory research can serve as powerful anticipatory data for prevention responses

Arsenic: global action

Arsenic is one of WHO's 10 chemicals of major public health concern. The most important action: is prevention of further exposure to arsenic by provision of a safe water supply The current recommended limit of arsenic in drinking-water is 10 μg/L 2030 Agenda for Sustainable Development: - "safely managed drinking water services" calls for tracking the population accessing drinking water which is free of fecal contamination and priority chemical contaminants, including arsenic.

Sources of drinking water

Available freshwater supplies either: - Surface water: natural open to atmosphere (e.g., rivers, lakes, reservoirs, estuaries, etc.) - Groundwater: underground, in aquifers

Arsenic prevention and control, USA

EPA: - Limits on the amount of arsenic that industrial sources can release to the environment - Restricted or cancelled many of the uses of arsenic in pesticides - limit of 10 ppb or 10 μg/Lfor arsenic in drinking water OSHA: - has set a permissible exposure limit (PEL) of 10 micrograms of arsenic per cubic meter of workplace air (10 μg/mÑ) for 8 hour shifts and 40 hour work weeks FDA: - Based on its testing, proposed an action level, or limit, of 100 parts per billion (ppb) for inorganic arsenic in infant rice cereal (2016)

Ecology

Ecology: focuses on the interactions among organisms and their physical environment Population Ecology: Study of dynamics of species' populations, interactions, change over time and space Without constraints, populations (human and non-human) grow exponentially Resource limits, predation, parasitism, competition constrain growth at a population's carrying capacity Population decline = deaths > births; Declines in all populations of a species = extinction Conservation biology seeks to halt extinction Understanding the environment in ecological terms is important in our understanding of environmental health

Systems thinking: From ecology to human health

Ecosystem Health and Human Health: Interconnectedness and complexity Inter-relationships and reciprocity Feedbacks Nestedness: nothing exists outside of its ecology. Interdependence, cycling, non-linearity, uncertainty. Rethinking of waste as part of ecological processes.

Ecosystem services

Ecosystem functions support human health and well-being Millenium Ecosystem Assessment (MA) categories: Provisioning: water, food, fiber, fuel, genes, etc. (medicine) Regulating: climate, air & water quality, pollination, erosion, disease transmission, etc. Cultural: cultural, spiritual, religious, aesthetic, knowledge, recreation, ecotourism, etc. Supporting: photosynthesis, primary production, water cycling, nutrient cycling, etc. (Habitat maintenance) Ecosystem services: essential benefits to humans provided by ecosystems, such as pollination of food crops, purification of water, and oxygen provision oxygen

Planetary Health

Ecosystem health is critical pillar in the foundation of human health and wellbeing and environmental public health "Human health and human civilization depend on flourishing natural systems" We (humans) are in part responsible for the stewardship of those natural systems Are we threatening the health of future generations to realize economic and developmental gains today?

Lecture 2: Environmental Health and Ecosystem services (Ch. 2, 3) Ecosystem health as a foundation for human health

Ecosystems: Complex system of organisms, their environment and the interactions that connect them Provide a range of services that support life

Improving Global environmental health

Housing: Ensure clean fuel for heating and cooking, no mold or pests, and remove unsafe building materials and lead paint Schools: Provide safe water, sanitation and hygiene, free of noise and air pollution Health facilities: Ensure safe water, sanitation and hygiene, and reliable electricity Urban planning: Create more green spaces, safe walking and cycling paths. Transport: Reduce emissions and increase public transport. Agriculture: Reduce the use of hazardous pesticides and no child labor. Industry: Manage hazardous waste and reduce the use of harmful chemicals. Health sector: Monitor health outcomes and educate about environmental health effects and prevention measures

Ecosystem services

Human beings benefit from ecosystems in many ways: Pollination Pest and disease management Fresh water, food, fibre, habitat and genetic resources Recreation and tourism Spiritual health, cultural identity Erosion prevention Protection from natural disasters Carbon sequestration and storage Air and water pollution control Nutrient cycling and soil fertility

Figures in Environmental Health and Sentinel Events in History

Edwin Chadwick: British lawyer (1800-1890) Founding president of the Association of Public Sanitary Inspectors Helped reform the "Poor Laws" After an outbreak of Typhys, he reported on The Sanitary Condition of the Labouring Population of London (1842) and improved the London sewer systems John Snow: British physician (1813-1858) "Father of Epidemiology" Researched the source of the 1854 cholera epidemic, and helped control the outbreak in Soho London by removing the handle of the Broad Street drinking water pump His findings inspired changes in the water and waste water systems of London. This led to similar changes in other cities in other countries, -is recognized as improving population health globally William Farr: British physician (1807-1883) "Father of Medical Statistics" Compiled vital statistics, including mortality data Defined risks based on professions and environments John Muir (1833-1914) Ecological thinker and Political Spokesperson "Father of the National Parks" Founded the Sierra Club Promoted preservation of the natural environment in the post-Industrial Revolution era Rachel Carson (1907-1964) American marine biologist for the US Bureau of Fisheries and author Wrote Silent Spring (1962) calling attention to the dangers of pesticides for people and the environment, focusing on the DDT Spurred the American environmental movement, a ban on DDT, and lead to the creation of the US Environmental Protection Agency (EPA)

Emerging contaminants

Emerging contaminants: contaminants not yet regulated by drinking water standards Example: PFAS/ PFOS

Define Terms In Environmental Health And Concepts Within The Field

Environment Definitions: - A broad definition: "the circumstances, objects, or conditions by which one is surrounded" ~ Merriam-Webster A specific definition: "the complex physical, chemical, and biological factors (noise, pesticides, and living organisms) that act upon an organism or an ecological community and ultimately determine its form and survival" ~ Howard Frumkin Health Definitions: Negative definition: "Health is the absence of disease" Positive definition: Health is a state of complete physical, mental, and social well-being, and not merely the absence of disease (WHO definition) Holistic definition: Health is a determinant of well-being - Health promotion/ecological approach Environmental Health: Definitions World Health Organization - "Environmental health comprises those aspects of human health, including quality of life, that are determined by physical, chemical, biological, social and psychosocial factors in the environment. It also refers to the theory and practice of assessing, correcting, controlling, and preventing those factors in the environment that can potentially affect adversely the health of present and future generations." Agency for Toxic Substances and Disease Registry - "Environmental health is the branch of public health that protects against the effects of environmental hazards that can adversely affect health or the ecological balances essential to human health and environmental quality."

Environmental Public health actions: Prevention

Environmental Public Health Mission: control hazards, promote health, prevention At the individual level: example with hazardous chemicals at home: Primary prevention: Ban the product at home Secondary prevention: wear individual protection when using the product or use it only outside Tertiary prevention: regularly visit the physician for checking potential symptoms At the population level: example with leaded gasoline P: Ban leaded gasoline S: Education awareness, taxes T: Filtering cars' emissions / surveillance of saturnism (lead poisoning)

Environmental and Occupational epidemiology

Environmental epidemiology: the study of environmental agents to which large numbers of people are exposure involuntarily Occupational Epidemiology: study of illness or injury associated with workplace exposures Environ. & Occ. Epidemiological data can identify a harmful exposure and quantify the amount of harm due to the exposure

The notion of dose-response

Every individual will respond to a toxicant in an unique way The notion of dose-response relationship refers to a curve representing the correlation between a toxicant's dose and an organism's response

USA: Municipal drinking water is monitored for safety

Find water quality of any municipal water system in the USA: SDWIS https://www3.epa.gov/enviro/facts/sdwis/search.html

The role of environmental health in improving life expectancy

From chamber pots => Sewage municipal sewage systems From contaminated sources => Treated potable water

Lead: Burden of disease

Globally, In 2016, lead exposure accounted for 540 000 deaths and 13.9 million years of healthy life lost (DALYs)) The highest burden is in low-and middle-income countries As of 2018, only 36% of countries had confirmed that they have legally binding controls on the production, import, sale and use of lead paints

The Local, Federal, And International Agencies Involved in Environmental Health

Local Health Departments: County and city health departments handle a range of environmental problems, and coordinate their programs with state health and environmental agencies. The National Association of County and City Health Officials (NACCHO) provides technical assistance to county and city health departments Under the Executive Branch: Federal Environmental Health Agencies (USA): - Environmental Protection Agency (EPA) - Department of Health and Human Services: Center for Disease Control (CDC) Agency for Toxic Substances and Disease Registry (ATSDR) Center for Environmental Health (NCEH) National Inst for Occupational Safety and Health (NIOSH) National Institute of Health (NIH) Food and Drug Administration-Nat'l Center for Environmental Health (NCEH) Federal agencies cont. - Department of Labor: Occupational Safety and Health Administration (OSHA) - Department of the Interior National Parks - Department of Commerce National Oceanic and Atmospheric Administration - Department of Homeland Security: FEMA - Department of Agriculture: Other Cabinet-level Depts include: Commerce, Defense, Education, Energy, Housing and Urban Development, Interior, Justice, State, Transportation, Treasury, and Veterans Affairs

Measurement in epidemiology

Measures of occurrence and frequency: e.g. count, prevalence, incidence rate (all descriptive) Measures of association: e.g. risk ratio, risk difference, odds ratio (understand the causes) Measures of effect: burden of disease e.g. attributable fraction, exposed attributable fraction, population attributable fraction, Years of Life Lost, DALY (Disability Adjusted Life Years), QALY (Quality Adjusted Life Years) Compare exposures and suggest interventions

Ecosystem Health <=> Human Health (Mercury example)

Mercury is a naturally occurring chemical: Coal burning, gold mining, chloralkali manufacturing plants currently contribute the vast majority of the mercury released into our environment Harmful when it contaminates fresh and seawater areas Negative health effects include neurological and chromosomal problems. - Limit consumption of certain fish, like albacore tuna

Environmental Public Health: Mission, Successes and Challenges

Mission: control hazards, promote health, prevention Two centuries of success: 1800's: sanitary movement reduced infectious disease deaths, life expectancy increased USA: life expectancy from 47 to 79 years between 1800-2016; Chad: life expectancy is currently 49.8 years) 1970s: strong environmental laws led to cleaner air, safer drinking water, recovery of rivers/lakes Challenges: Industrialized nations: environmental threats from multiple small sources, air pollution, climate change; require participation from broad range of society Developing countries: climate change, water shortages, contaminated drinking water, indoor air pollution, inadequate worker protections, injuries, disasters, etc.

Multiple levels (scales) of toxicity

Molecule <=> organelle <=> cell <=> functional unit <=> organ <=> body <=> population ^ Toxicity can occur at multiple levels in humans Increased cancer incidence due to exposure to arsenic Weight loss due to impaired nutrient absorption in gut Renal failure due to heavy metal exposure Infertility to do damage to supportive Leydig cells in testes Cellular loss due to apoptosis of toxicant exposure Mitochondrial disruption due to pesticide exposure DNA mutations due to radiation or chemical mutagen

Environmental public health surveillance

Monitoring environmental exposures and health status to identify and solve community environmental health problems: Health data: national surveys (e.g. vital statistics reports, etc.) - U.S. CDC's Environmental Public Health Tracking Program: air pollution & asthma, cancer & water contamination, extreme heat & heat-related illness, etc. Environmental data: biomonitoring; air, water, food data; site locations; ecosystem, built env. data Challenges: - data: different spatial, temporal scales; large volumes - statistical: correlation not causation, chance findings, etc.

Routes of exposure

Mostly Ingestion Skin exposure Breathing contaminated aerosols from showers, toilet flushing, cooling towers - Example: Legionella

Epigenetic Changes From Environmental Exposures

Multigenerational Effects VS Transgenerational Effects From Prenatal exposure To Endocrine Disrupting Chemicals (EDCS): Effects of environmental exposures (EDCs) observed in the F1 or F2 generations are considered to be multigenerational. F3 had no direct exposure and so the effects are transgenerational

Toxicological measure: NOAEL AND LOAEL

NOAEL: No Observable Adverse Effect Level - The threshold where no effects are observed LOAEL: Lowest Observable Adverse Effect Level - The concentration level where effects start to be observed

Arsenic: Key facts

Naturally present in groundwater in some countries Highly toxic in its inorganic form Contaminates water and food Confirmed carcinogen

Study designs in Epidemiology

Randomized Controlled Trials: People are allocated at random (by chance alone) to receive the clinical interventions. One group is assigned to the control. Cohort studies: Investigate the causes of disease establishing links between risk factors and health outcomes. Usually prospective. Case control studies: Two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute. Looks back retrospectively to see exposures over time and determine relationships. Cross sectional studies: Make comparisons between groups at a single point in time. Longitudinal studies: make comparisons between groups over time.

Health Disparities

Rural, low-income communities, people of color, and women and girls are disproportionately harmed by environmental exposures related to unsafe water, lack of sanitation and inadequate hygiene: - Gender - Economic - Race and Ethnicity - Geography

Arsenic: Prevention and control

Short-term actions: Reduce levels of arsenic in drinking-water. - Substitute high-arsenic sources, such as groundwater, with low-arsenic, microbiologically safe sources such as rain water and treated surface water. - Discriminate between high-arsenic and low-arsenic sources - Blend low-arsenic water with higher-arsenic water to achieve an acceptable arsenic concentration level - Install arsenic removal systems (centralized or domestic) - Ensure the appropriate disposal - Bangladesh: extend depth of wells (>150 meters deep) Long-term actions: Education: - risks of high arsenic exposure and the sources of arsenic exposure - including the intake of arsenic by crops (e.g. rice) from irrigation water and the intake of arsenic into food from cooking water High-risk populations should also be monitored for early signs of arsenic poisoning -sometimes skin problems.

Lead: Successes and challenges

Successes: Phase out of leaded gasoline in most countries - decline in population - level blood lead concentrations. - Only 3 countries continue to use leaded fuel Challenges: Phasing out of lead paint: so far only one third of countries have introduced legally binding controls on lead paint

Introduction to toxicology

Types of questions that can be addressed in toxicology: How can Benzene lead to leukemia? What are the biological mechanisms? What level of exposure is associated with observed impacts of formaldehyde? What level of carbon monoxide (CO) is considered safe? Do the toxicological mechanisms support an epidemiological finding?

Lead: Global activity

WHO: has identified lead as 1 of 10 chemicals of major public health concern The Global Alliance to Eliminate Lead Paint: Voluntary collaborative partnership of governments, private industry, and NGOs that works to promote the phase-out of the use of lead in paint. Sustainable Development Goal targets: 3.9: By 2030 substantially reduce the number of deaths and illnesses from hazardous chemicals

Water-related illnesses

Waterborne diseases (diseases transmitted by water) - Cholera, typhoid, Giardiasis Water-washed diseases (caused by lack of water and poor hygiene) - Trachoma, Scabies Water-based diseases (caused by parasites that spend part of their life cycle in water) - Schistosomiasis, Filariasis, Guinea Worm Water-related insect vector diseases (caused by insect vectors that breed in water) - Yellow fever, Dengue, Malaria Ex. Cholera Cause: Bacteria Symptoms: diarrhea, vomiting, dehydration Ex. Trachoma Cause: Bacteria Symptoms: Eye infection, blindness Ex. Schistosoma Cause: Worm Symptoms: Diarrhea, blood in urine, liver/kidney failure

Vulnerable population: Children

Young children absorb 4-5 times as much ingested lead as adults Children can absorb 40% to 50% of an oral dose of water-soluble lead compared with 3% to 10% for adults Greater toxicity in children is based on sensitivity of developing organ systems, especially the developing nervous system Children have different and unique exposures Increased food and liquid intake per kg body weigh Increased GI absorption of some toxins (Pb) Increased respiratory and cardiac output Increased hand-mouth and object-mouth behaviors Proximity to the ground Limited understanding of warnings Longer life expectancy (bioaccumualate)

Environmental Agent:

chemicals or factors in the environment which humans are exposed to that cause adverse health effects

The three pillars in the mission for Environmental Public Health are:

control hazards, promote health, prevention