Indoor Air Pollution Ch 17

Indoor air pollution Indoor air contains higher concentrations of pollutants than outdoor air (up to 70x) Synthetic materials not comprehensively tested To reduce heat loss & improve energy efficiency: ventilation systems are sealed off & recirculate air windows do not open This traps pollutants inside. Indoor air pollution usually is a greater threat to human health than outdoor air pollution. Avg. U.S. citizen spends 90% of time indoors 6,000 people die per day from indoor air pollution Pollution levels inside cars in traffic clogged urban areas can be up to 18 times higher.

Indoor Air Pollution--Developing World From burning wood, charcoal, dung, crop waste With little to no ventilation Soot and carbon monoxide Causes pneumonia, bronchitis, allergies, cataracts, asthma, heart disease, cancer & death ~1.6 million deaths/year

Indoor Air Pollution--Developed World According to the EPA, the 4 most dangerous indoor air pollutants in developed countries are: Tobacco smoke Formaldehyde Radioactive radon-222 gas Very small fine & ultrafine particles

Other Important Indoor Air pollutants Sources Nitrogen dioxide Carbon monoxide Volatile Organic Compounds (VOCs) House dust mites (& other allergens… from pets) Chlorinated organic compounds (ex. pesticides) Asbestos & man-made mineral fibers Sources Building materials Furnishings & fabrics Glues Cleaning products Combustion appliances (cooking & heating) Open fires Smoking Living organisms Outdoor air

Tobacco Smoke The most dangerous indoor pollutants in the developed world Secondhand smoke from cigarettes is especially dangerous Containing over 4000 dangerous chemicals Causes eye, nose, and throat irritation Smoking has declined in developed nations

Volatile Organic Compounds (VOCs) The most diverse group of indoor air pollutants Released by everything from plastics and oils to perfumes and paints Ex. formaldehyde, which leaks from pressed wood and insulation, irritates mucous membranes and induces skin allergies Ex. pesticides, which are found indoors more often than outdoors due to seepage Most VOCs are released in very small amounts Unclear health effects due to low concentrations

Radon-222 colorless, tasteless, odorless, radioactive gas from decay of U-238 found in some soils & rocks can seep into some houses Most homes are now radon resistant 55% of our exposure to radiation comes from radon May harm lungs from long term exposure. increases the risk of lung cancer Chance increase more if a smoker (synergistic effect) causes 20,000 deaths a year in the U.S. Reducing the risk Sealing cracks in floors and walls Simple systems using pipes and fans

Sources & paths of entry for indoor radon-222 gas

Radon risk across the U.S.

Living organisms can pollute indoors Dust mites feed on human skin & dust live in materials such as bedding & furniture fabrics can cause asthma attacks & allergic reactions Fungi, mold, mildew, airborne bacteria cause severe allergies, asthma, & other respiratory ailments Animal dander worsen asthma

Major Indoor Pollutants Pollutant Source Health Effects 1, 1, 1-Trichloroethane Aerosol sprays Dizziness, breathing irregularities Asbestos Pipe insulation, ceilings, floor tiles, oven mitts Lung Cancer and asbestosis Benzo-a-pyrene Tobacco smoke, woodstoves Lung Cancer Carbon Monoxide Faulty furnaces, cigarette smoke Headache, heartbeat irregularities, death, CO has 250x affinity for hemoglobin than O2 http://www.metricmind.com/ac_honda/main.htm

Pulp and paper mills, water and wastewater plants Cancer Chloroform Pulp and paper mills, water and wastewater plants Cancer Formaldehyde Paneling, particle board, furniture, carpeting, adhesives Nausea, dizziness, irritation of throat, eyes, and lungs Methylene chloride Paint strippers and thinner – persistent Nerve disorders, diabetes Nitrogen oxides Furnaces, stoves, fireplaces and vents Headaches, irritated lungs Para-dichlorobenzene Air fresheners, mothballs http://www.metricmind.com/ac_honda/main.htm

Soil and rock near house foundation, concrete Lung cancer Radon – 222 Soil and rock near house foundation, concrete Lung cancer Styrene Carpets, plastics, Kidney & liver damage Tetrachlor- ethylene Dry-cleaning fluid Nerve disorders, damage to liver and kidneys, cancer Tobacco Smoke Cigarettes and other smoking sources Lung cancer and heart disease Organic Material (Living Organisms) Dust mites, fungal and algal spores, dust (human skin), animal dander, hair, carpet fibers, fur Allergies, coughs, sneezing, eye irritation, sore throats, difficulty breathing http://www.metricmind.com/ac_honda/main.htm

Sick Building Syndrome A sickness produced by indoor pollution w/ general & nonspecific symptoms Ex. dizziness, headaches, coughing, sneezing, nausea, burning eyes, chronic fatigue, irritability, eye/nose/throat irritation, dry skin, nasal congestion, difficulty breathing, nose bleeds, flu-like symptoms persistent set of symptoms in >20% population complaints/Symptoms relieved after exiting building causes(s) not known or recognizable New buildings are more commonly “sick” than old ones because of reduced air exchange. Can be solved with low-toxicity building materials & good ventilation

Building Related Illness Also due to exposure to indoor air pollutants Recognizable Causes Clinically Recognized Disease Examples Pontiac Fever – Legionella spp. Legionnaire's Disease Hypersensitivity Pneumonitis Humidifier Fever Asthma Allergy Respiratory Disease Chronic Obstructive Pulmonary Disease

Reducing Indoor Air Pollution Little effort has been devoted to reducing indoor air pollution even though it is more harmful to human health than outdoor air pollution Environmental & health scientists call for us to focus on preventing air pollution (especially indoor) in developing countries.

Use adjustable fresh air vents for work spaces Solutions Indoor Air Pollution Prevention Cleanup or Dilution Cover ceiling tiles & lining of AC ducts to prevent release of mineral fibers Use adjustable fresh air vents for work spaces Increase intake of outside air Ban smoking or limit it to well ventilated areas Change air more frequently Set stricter formaldehyde emissions standards for carpet, furniture, and building materials Circulate a building’s air through rooftop green houses Figure 19.20 Solutions: ways to prevent and reduce indoor air pollution. QUESTION: Which two of these solutions do you think are the most important? Prevent radon infiltration Use exhaust hoods for stoves and appliances burning natural gas Use office machines in well ventilated areas Use less polluting substitutes for harmful cleaning agents, paints, and other products Install efficient chimneys for wood-burning stoves Fig. 19-20, p. 461

We can reduce indoor air pollution In developed countries: Use low-toxicity material Monitor air quality Keep rooms clean Limit exposure to chemicals Allow for better mixing of indoor & outdoor air In developing countries: Dry wood before burning Cook outside Use less-polluting fuels (natural gas)

We can reduce indoor air pollution The amount of air available (for mixing of indoor & outdoor air) to dilute pollutants is an important indicator of the likely contaminant concentration Indoor air can mix with outside air by 3 mechanisms infiltration natural ventilation forced ventilation

Mixing of Indoor & Outdoor Air Infiltration natural air exchange that occurs between a building & its environment when doors & windows are closed leakage through holes or openings in the building Influenced by: pressure differentials inside & outside the building temperature differentials inside & outside of bldg ~in winter, warm air inside wants to rise  exits through cracks in ceiling & draws in outside air how fast wind is blowing

Mixing of Indoor & Outdoor Air Natural ventilation 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 & blowers

• Do not buy furniture and other products containing formaldehyde. What Can You Do? Indoor Air Pollution • Test for radon and formaldehyde inside your home and take corrective measures as needed. • Do not buy furniture and other products containing formaldehyde. • Remove your shoes before entering your house to reduce inputs of dust, lead, and pesticides. • Test your house or workplace for asbestos fiber levels and for any crumbling asbestos materials if it was built before 1980. • Don't live in a pre-1980 house without having its indoor air tested for asbestos and lead. • Do not store gasoline, solvents, or other volatile hazardous chemicals inside a home or attached garage. Figure 19.21 Individuals matter: ways to reduce your exposure to indoor air pollution. QUESTION: Which three of these actions do you think are the most important? • If you smoke, do it outside or in a closed room vented to the outside. • Make sure that wood-burning stoves, fireplaces, and kerosene- and gas-burning heaters are properly installed, vented, and maintained. • Install carbon monoxide detectors in all sleeping areas. Fig. 19-21, p. 461