WEEK 2: Environmental Health Flashcards
What is health?
“State of complete physical, mental and social well-being and not merely the absence of disease or infirmity” World Health Organisation (WHO), 1948
What is an environment?
“ All that which is external to the individual human Host. It can be divided into physical, biological, social, cultural, any or all of which can influence health status in populations” Last 1995
What is environmental health?
“Those aspects of human health, including the quality of life that are determined by physical biological, social and psychosocial factors in the environment.
EH 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” WHO 1993
Discuss Physical and chemical environment.
Physical environment: Includes everything from the immediate home and work environments to regional national and global environments.
-Air, water, food and soil, chemical composition including radiation, seasonal changes, etc.
Noise – Vibration- annoyance & discomfort, fatigue
Extremes of temperature – headaches
Biological environment.
Outline
Examples of Biological contaminants
-Bacteria,
-Molds (fungi), mildew,
-Viruses
-Animal dander (tiny scales of animal skin) and cat -Saliva
-House dust,
-Mites,
-Cockroaches, and pollen.
Protein in urine from rats and mice - potent allergen (become airborne when it dries)
LEPTOSPIROSIS from tops of soda cans from dry rat urine which contain toxic substances… Pest control.
Key Contaminated central air handling systems - breeding grounds for mold, mildew, and other sources of biological contaminants and can then distribute these contaminants through the home or workplace.
Environmental quality an important direct and indirect determinant of health (Smith 1999)
How many of the following are caused by the environment?
-Acute Respiratory Infections (ARIs),
- TB cases and
-Diarrheal diseases,
-Malaria cases,
-Chronic pulmonary diseases are attributable to environmental factors (Smith 1999). In their study to assess the global ill-health attributable to the environment.
-Approximately 40- 60% of the Acute Respiratory Infections (ARIs),
-20-25% of TB cases and
-80-90 % of diarrheal diseases,
-70-90% 0f malaria cases,
-33-50 % of chronic pulmonary diseases are attributable to environmental factors (Smith 1999). In their study to assess the global ill-health attributable to the environment.
Describe the major effects of environment on health in the developed and developing countries.
Burden of Disease
-Over 5 million children 0-14 years of age die, from diseases related to the environment, such as malaria, dengue, acute respiratory infections, and diarrhea.
-About 3.5-5 million cases of acute pesticide poisonings occur each year in DCs
-Air pollution
The presence of one or more contaminants in air in quantities, characteristics, and duration such as to be injurious to human, plants, or animal life, and property.
Includes both the particulate matter & chemical compounds
There are various types of pollutants in the atmosphere
Increases due to extraction & burning of coal
Air pollution not new
Started as far back 13th century, complaints
about coal dust & soot over London
As industry spread across the globe, so did air pollution
Worst pollution occurred in London in 1952
where >4000 people died & 8 000 died
within 6 months
Outline outdoor causes of air pollution.
-Transportation
-Construction and road rust
-Emission
-Biomass burning
-Open waste burning
-Industries
-Power plants
-Brick kilns
Outline sources of indoor air pollution.
Living Room:
Tobacco Smoke: Smoking indoors releases a complex mixture of chemicals, including particulate matter, volatile organic compounds (VOCs), and carcinogens, which can pose serious health risks to occupants.
Animal Fur and Dander: Pets can shed fur and dander, which are common indoor allergens and can trigger allergic reactions in susceptible individuals.
- Kitchen:
Cooking Emissions: Cooking activities, especially those involving high temperatures or frying, can release pollutants such as particulate matter, carbon monoxide (CO), nitrogen dioxide (NO2), and volatile organic compounds (VOCs) from cooking oils, gases, and food particles.
Gas Appliances: Gas stoves, ovens, and water heaters can emit combustion by-products, including nitrogen dioxide (NO2) and carbon monoxide (CO), if not properly ventilated or maintained.
- Bedroom:
Dust Mites: Dust mites thrive in bedding, mattresses, and upholstered furniture and produce allergenic proteins that can trigger allergic reactions and exacerbate asthma symptoms.
Volatile Organic Compounds (VOCs): VOCs emitted from household products such as paints, varnishes, cleaning agents, and air fresheners can contribute to indoor air pollution and may cause respiratory irritation or other health effects.
- Laundry Room:
Dryer Vents: Clothes dryers can release lint, dust, and VOCs into the air, especially if the dryer vents are clogged or improperly installed.
Laundry Products: Detergents, fabric softeners, and bleach can emit VOCs and other chemicals during use, contributing to indoor air pollution.
- Bathroom:
Mold and Mildew: Moisture-rich environments in bathrooms can promote the growth of mold and mildew, which release spores and allergens into the air and may cause respiratory issues and allergic reactions.
Volatile Organic Compounds (VOCs): VOCs from personal care products, such as aerosol sprays, perfumes, and hair products, can contribute to indoor air pollution in bathrooms.
- Air Conditioning Units:
Poor Maintenance: Improperly maintained air conditioning units can harbor mold, bacteria, and other contaminants, which can be circulated into indoor air during operation.
Filter Contaminants: Air filters in HVAC systems can accumulate dust, pollen, pet dander, and other particles, potentially leading to indoor air pollution if not regularly cleaned or replaced.
Although air pollution can produce adverse impacts on humans in many ways (e.g. eye irritation or nausea due to nuisance odors) the most important health effects of air pollution are associated with the respiratory system.
These impacts can be either direct (impacting the respiratory system itself) or transmissive (the respiratory system transmits the agent to another part of the body)
Describe the effects of air pollution on human health.
Direct Effects: shortness-of-breath, reduced lung function, development of lung diseases, exacerbation of existing lung disease (e.g. initiating an asthmatic crisis), etc.
Transmissive Effects: transmission of acutely toxic substances, cardiovascular effects, transmission of carcinogenic or teratogenic compounds, etc.
These impacts can also be either short-term or long-term and can produce adverse impacts in terms of both mortality (death) and morbidity.
Outline Indoor contamination and potential health effects: Examples (WHO 2002).
View table on notes.
Incomplete oxidation of carbon results in the production of carbon monoxide.
Natural CO formation occurs from photochemical reactions in the troposphere, volcanoes, forest fires, etc.
Discuss the effects of CO.
Breathing air with a high concentration of CO reduces the amount of oxygen that can be transported in the blood stream to critical organs like the heart and brain.
At very high levels, which are possible indoors or in other enclosed environments, CO can cause dizziness, confusion, unconsciousness and death.
Very high levels of CO are not likely to occur outdoors. However, when CO levels are elevated outdoors, they can be of particular concern for people with some types of heart disease.
These peoplealready have a reduced ability for getting oxygenated blood to their hearts in situations where the heart needs more oxygen than usual. They are especially vulnerable to the effects of CO when exercising or under increased stress.
In these situations, short-term exposure to elevated CO may result in reduced oxygen to the heart accompanied by chest pain also known as angina.
Anthropogenic sources are “man-made” sources, typically by incomplete combustion. CO can become high indoors by incomplete combustion in an improperly operating furnace.
Sources of lead emissions vary from one area to another.
Outline the different sources of lead.
At the national level, major sources of lead in the air are ore and metals processing and piston-engine aircraft operating onleaded aviation fuel.
Other sources are waste incinerators, utilities, and lead-acid battery manufacturers.
The highest air concentrations of lead are usually found near lead smelters.
Volcanic activity and soil are the primary natural sources of atmospheric lead.
Some feel leaded gas provides more power and less engine knocking for airplane engine operation.
Piston aviation engines have historically used leaded gas to provide these desired qualities.
Discussthe effects of lead on human health.
Once taken into the body, lead distributes throughout the body in the blood and is accumulated in the bones.
Depending on the level of exposure, lead can adversely affect the nervous system, kidney function, immune system, reproductive and developmental systems and the cardiovascular system.
Lead exposure also affects the oxygen carrying capacity of the blood.
The lead effects most commonly encountered in current populations are neurological effects in children and cardiovascular effects (e.g., high blood pressure and heart disease) in adults.
Infants and young children are especially sensitive to even low levels of lead, which may contribute to behavioral problems, learning deficits and lowered IQ.
Lead Is a cumulative poison. It is ingested in food and water (5-10% absorbed) as well as being inhaled (20-50%).
Describe how Ground Level Ozone is formed.
Ozone is formed in the atmosphere when energetic ultraviolet (UV) radiation dissociates molecules of oxygen, O2, into separate oxygen atoms.
Free oxygen atoms can recombine to form oxygen molecules but if a free oxygen atom(O-2) collides with an oxygen molecule(O2), it joins up, forming ozone (O3).
