INDOOR AIR POLLUTION

• Just because you can’t see it, doesn’t mean it isn’t there.

• When was the last time you dusted your house. What are its components?

• The levels of CO2 in the air and potential health problems are:

• 250 - 350 ppm – background (normal) outdoor air level• 350- 1,000 ppm - typical level found in occupied spaces with

good air exchange.• 1,000 – 2,000 ppm - level associated with complaints of

drowsiness and poor air.• 2,000 – 5,000 ppm – level associated with headaches,

sleepiness, and stagnant, stale, stuffy air. Poor concentration, loss of attention, increased heart rate and slight nausea may also be present.

• >5,000 ppm – this indicates unusual air conditions where high levels of other gases could also be present. Toxicity or oxygen deprivation could occur. This is the permissible exposure limit for daily workplace exposures.

• >40,000 ppm - this level is immediately harmful due to oxygen deprivation.

Indoor Pollution• Mold• Dust• Animal Dander• Pollen• Carbon Monoxide• Radon• Lead• Asbestos

• Cleaning fumes• Dust mites• Cigarette smoke• Fabric fibers• Chemical vapors

INDOOR AIR POLLUTION• Indoor air pollution usually is a greater threat

to human health than outdoor air pollution.• According to the EPA, the four most

dangerous indoor air pollutants in developed countries are:– Tobacco smoke.– Formaldehyde.– Radioactive radon-222 gas.– Very small fine and ultrafine particles.

Tobacco SmokeWhile these ingredients are approved as additives for foods, they were not tested by burning them, and it is the burning of many of these substances which changes their properties, often for the worse. Over 4000 chemical compounds are created by burning a cigarette – 69 of those chemicals are known to cause cancer. Carbon monoxide, nitrogen oxides, hydrogen cyanides and ammonia are all present in cigarette smoke. Forty-three known carcinogens are in mainstream smoke, sidestream smoke or both.

INDOOR AIR POLLUTION

• Household dust mites that feed on human skin and dust, live in materials such as bedding and furniture fabrics.– Can cause asthma

attacks and allergic reactions in some people.

Figure 19-12

Formaldehyde• Formaldehyde has been used for decades to embalm dead

bodies for open casket burials. It is a preservation fluid that replaces the blood, it is a recognized cancer causing agent (carcinogen) such as leukemia.

• Formaldehyde is a colorless gas with a characteristic pungent odor. It is an important precursor to many other chemical compounds, especially for polymers. Formaldehyde is an intermediate in the oxidation (or combustion) of methane as well as other carbon compounds, e.g. forest fires, in automobile exhaust, and in tobacco smoke.

• The particle board is used underneath wood veneer and plastic laminate.

Chloroform

Benzo-a-pyrene

Styrene

Radon-222

Methylene Chloride

Tobacco Smoke

Carbon Monoxide

Asbestos

Nitrogen Oxides

1, 1, 1-Trichloroethane

Particulates

FormaldehydeTetrachloroethylene

Para-dichlorobenzene

Fig. 19-11, p. 453

Lead

Asbestos

Case Study: Radioactive Radon

• Radon-222, a radioactive gas found in some soils and rocks, can seep into some houses and increase the risk of lung cancer.

Sources and paths of entry for indoor radon-222 gas.

Figure 19-13

Asbestos• Asbestos became increasingly popular

among manufacturers and builders in the late 19th century because of its sound absorption, average tensile strength, its resistance to fire, heat, electrical and chemical damage, and affordability. It was used in such applications as electrical insulation for hotplate wiring and in building insulation. When asbestos is used for its resistance to fire or heat, the fibers are often mixed with cement (resulting in fiber cement) or woven into fabric or mats.

• Mesothelioma – a form of lung cancer

Air Filters and vacuumes

Fig. 19-21, p. 461

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.

• 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. 19-20, p. 461

SolutionsIndoor Air Pollution

Prevention

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 airBan smoking or limit it to well ventilated areas

Change air more frequentlySet stricter formaldehyde emissions standards for carpet, furniture, and building materials

Circulate a building’s air through rooftop green houses

Prevent radon infiltration Use exhaust hoods for stoves and appliances burning natural gasUse 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

Cleanup or Dilution