Indoor Air Pollution Chapter 12, Sections 5 & 6: Types, Sources, & Effects

Objective Starting new unit: Risk & Toxicology Identify types and sources of indoor air pollution. Explain how indoor air pollutants affect human health. Describe ways to reduce indoor air pollution. Read the passage…

Why is indoor air quality important? Levels of common pollutants are generally higher indoors 70 to 90% of time spent indoors home, work, school, cars Many significant pollution sources in the home gas cookers, paints, glues Personal exposure to many common pollutants is driven by indoor exposure... May lead to cancer & other ailments. Especially important for susceptible groups: sick, old, very young, pregnant women, smokers, people with respiratory/heart problems, factory workers Typically 2-5X higher levels of pollutants indoors vs. outdoors particulate matter, even pesticides (from being tracked indoors, then nowhere to disperse once trapped in the home) inside your car, pollution levels can be up to 18X higher than outside (esp. in high traffic areas)

Exposure Time spent in various environments in US and less- developed countries:

Respiratory System Defense: Broken down by smoking, causing Nose hairs Mucus Sneezing/coughing Cilia (line upper respiratory tract) Broken down by smoking, causing Lung cancer Asthma Chronic bronchitis Emphysema Cilia trap pollutants and expel to throat (where you swallow or cough up)

Humans Die from Pollution Annually, U.S. estimates 65,000-200,000 premature deaths from outdoor pollution Indoor pollution included: 150,000-350,000 premature deaths Worldwide: 2.7 million premature deaths Millions more face illness 350,000 deaths annually from air pollution = 1-2 fully loaded jumbo jets crashing each day with no survivors

House of Commons Select Committee Enquiry on Indoor Air Pollution (1991) “[There is] evidence that 3 million people have asthma in the UK… and this is increasing by 5% per annum.” “Overall there appears to be a worryingly large number of health problems which could be connected with indoor pollution and which affect very large numbers of the population.” [The Committee recommends that the Government] “develop guidelines and codes of practice for indoor air quality in buildings which specifically identify exposure limits for an extended list of pollutants…”

Top Dangerous Pollutants According to the EPA, 3 most dangerous indoor air pollutants: Cigarette smoke Formaldehyde (colorless, extremely irritating gas; used to manufacture many household materials) Radioactive Radon-222 Gas Additionally: Asbestos Burning candles indoors Tiny fibers of fiberglass (potentially potent carcinogen)

Sources of Indoor Air Pollutants Building materials Furniture Furnishings and fabrics Glues Cleaning products Combustion appliances (cookers and heaters) Other consumer products Open fires Tobacco smoking Cooking House dust mites, bacteria and moulds Outdoor air

Sick Building Syndrome A persistent set of symptoms in >20% population Headaches Fatigue Reduced Mentation Irritability Eye/nose/throat irritation Cause(s) not known or recognizable Complaints/Symptoms relieved after exiting building Dry Skin Nasal Congestion Difficulty Breathing Nose Bleeds Nausea Other ailments: dizziness, headaches, coughing, sneezing, nausea, burning eyes, chronic fatigue, flulike symptoms, “sick building syndrome”

Building Related Illness Clinically recognized disease (different from “sick building”) Exposure to indoor air pollutants Recognizable Causes Pontiac Fever – Legionella spp. Legionnaire's Disease Hypersensitivity Pneumonitis Humidifier Fever Asthma Allergy Respiratory Disease Chronic Obstructive Pulmonary Disease

Health Effects

Important Indoor Air pollutants Nitrogen dioxide Carbon monoxide Formaldehyde Asbestos Volatile Organic Compounds (VOCs) House dust mites (and other allergens, e.g. from pets) Environmental tobacco smoke Fine particles Radon Chlorinated organic compounds (e.g. pesticides) Asbestos and man-made mineral fibres

Nitrogen dioxide (criteria pollutant) Health Effects Nitrogen dioxide (criteria pollutant) Respiratory irritant Elevated risk of respiratory illness in children, perhaps resulting from increased susceptibility to respiratory infection; inconsistent evidence for effects in adults Concentrations in kitchens can readily exceed WHO and EPA standards

Carbon monoxide (criteria pollutant) Health Effects Carbon monoxide (criteria pollutant) An asphyxiant and toxicant Impairs perception, slows reflexes, headaches, drowsiness Hazard of acute intoxication, mostly from malfunctioning fuel-burning appliances and inadequate or blocked flues Possibility of chronic effects of long-term exposure to non- lethal concentrations, particularly amongst susceptible groups Reacts with hemoglobin in red blood cells and reduces the ability of blood to bring oxygen to body cells This is what kills you if you leave your engine running in a closed garage

Health Effects Formaldehyde Sensory and respiratory irritant and sensitizer Possible increased risk of asthma and chronic bronchitis in children at higher exposure levels Individual differences in sensory and other transient responses May cause: chronic breathing problems, dizziness, rash, headaches, sore throat, sinus and eye irritation, wheezing, nausea Sources: building materials (plywood, particle board, paneling), furniture, drapes, upholstery, adhesives (in carpeting/wallpaper), urethane (insulation), fingernail hardener (think about the strong odors from Mrs. Flatford’s room), wrinkle-free coating on permanent-press clothing “manufactured homes” (trailers)- 1/5,000 who live in trailers for 10+ years will develop cancer from prolonged formaldehyde exposure

Asbestos

Volatile Organic Compounds (VOCs) Health Effects Volatile Organic Compounds (VOCs) Occur in complex and variable mixtures Main health effects relate to comfort and well-being, but benzene (and other VOCs) are carcinogenic Concern about possible role of VOCs in the aetiology of multiple chemical sensitivity; also implicated in sick building syndrome Etiology = cause

Health Effects House dust mites House dust mites produce Der p1 allergen, a potent sensitizer Good evidence of increased risk of sensitization with increasing allergen exposure, but this does not necessarily lead to asthma Small reductions in exposure will not necessarily lead to reduced incidence and/or symptoms Indoor humidity is important Der p1 is an active digestive enzyme that can cause cell death in the lungs by ‘melting’ the glue like substance that binds cells together. The cell’s death in turn gives Der p1 access to the body and blood stream. 

Health Effects Fungi and bacteria Dampness and mould-growth linked to self-reported respiratory conditions, but little convincing evidence for association between measured airborne fungi and respiratory disease Insufficient data to relate exposure to (non- pathogenic) bacteria to health effects in the indoor environment

Environmental tobacco smoke (ETS) Health Effects Environmental tobacco smoke (ETS) Sudden infant death syndrome Lower respiratory tract illness Middle ear disease Asthma 12 million children exposed to secondhand smoke in homes

Fine particles (criteria pollutant) Health Effects Fine particles (criteria pollutant) Consistent evidence that exposure to small airborne particles (e.g. PM10) in ambient air can impact on human health; mechanisms uncertain Chronic Obstructive Pulmonary Disease and Cardiovascular Disease patients and asthmatics probably at extra risk Relative importance of indoor sources is unknown

Airborne Particulates Examination Take a particulate strip home to place next to your bed. Compare with school in 3 days. With your group of 3: Choose an area in the school Label your particulate strip Place your particulate strip Take a picture of your filled out, placed particulate strip Partner Roles: Scribe Installer Photographer

Predict! Which location in the school do you think will have the poorest air quality? Do you think the particulate strip next to your bed will be the same, better, or worse?

Health Effects Radon Naturally formed from the decay of uranium 55% of our exposure to radiation comes from radon Colorless, tasteless, odorless gas Found in nearly all soils (levels vary) Seeps upward through soil and quickly disperses to harmless levels outdoors BUT, indoors…

Radon: How it Enters Buildings Cracks in solid floors Construction joints Cracks in walls Gaps in suspended floors Gaps around service pipes Cavities inside walls The water supply Builds up indoors, especially in lower levels of structures, particularly where ventilation is poor Can cause lung cancer Estimated that 7,000 to 30,000 Americans die each year from radon-induced lung cancer Uranium miners… Only smoking causes more lung cancer deaths Risk level affected by: how much radon is in your home, how much time you spend in your home, and if you smoke http://www.epa.gov/iaq/radon/pubs/citguide.html#howdoes

Radon Risk: Non-Smoker Radon Level (pCI/L) If 1000 people who did not smoke were exposed to this level over a lifetime.. About X would get lung cancer This risk of cancer from radon exposure compares to … What to do: 20 8 Being killed in a violent crime Fix your home 10 4 3 10x risk of dying in a plane crash 2 Risk of drowning <1 Risk of dying in a home fire 1.3 Average indoor radon level .4 If you are a former smoker, your risk may be higher

Radon Risk: Smoker If you are a former smoker, your risk may be lower Radon Level (pCI/L) If 1000 people who smoke were exposed to this level over a lifetime.. About X would get lung cancer This risk of cancer from radon exposure compares to … What to do: Stop smoking and … 20 135 100x risk of drowning Fix your home 10 71 100x risk of dying in a home fire 8 57 4 29 100x risk of dying in a plane crash 2 15 2x the risk of dying in a car crash 1.3 9 Average indoor radon level .4 3 If you are a former smoker, your risk may be lower

Radon: Reducing the Risks Sealing cracks in floors and walls Simple systems using pipes and fans Test indoor air & compare with EPA’s acceptable levels More information Such systems are called "sub-slab depressurization," and do not require major changes to your home. These systems remove radon gas from below the concrete floor and the foundation before it can enter the home. Similar systems can also be installed in houses with crawl spaces.

Reducing Indoor Air Pollution

Reducing Indoor Air Pollutants Using simple stoves that burn more efficiently (reduces deforestation) Using simple solar cookers Breathing wall Absorbs indoor dirty air Exhales clean air Improve ventilation

Ventilation Movement of Air Into / Out of Homes Amount of air available to dilute pollutants important indicator of the likely contaminant concentration Indoor air can mix with outside air by three mechanisms infiltration natural ventilation forced ventilation

Ventilation Infiltration Temperature induced (stack effect) natural air exchange that occurs between a building and its environment when the doors and windows are closed leakage through holes or openings in the building pressure induced Due to pressure differentials inside and outside of the building Especially important with cracks and other openings in wall Temperature induced (stack effect) driven by air movement through holes in floors, ceilings in winter, warm air in a building wants to rise, exits through cracks in ceiling and draws in

Ventilation Natural ventilation Forced ventilation Trade-offs air exchange that occurs when windows or doors are opened to increase air circulation Forced ventilation mechanical air handling systems used to induce air exchange using fans and blowers Trade-offs cut infiltration to decrease heating and cooling costs vs. indoor air quality problems

What pollutants cause these problems? Suspended particulate matter: asthma Fine particles Ultrafine particles Sulfur dioxide: asthma/ bronchitis Nitrogen oxides: asthma/ bronchitis Volatile organic compounds: cancer