Atmosphere EAtmosphere E

Indoor Air QualityIndoor Air Quality

Indoor air quality refers Indoor air quality refers to the properties of to the properties of indoor air that affect indoor air that affect the health and well-the health and well-being of those in it.being of those in it.

There have been as There have been as many as 900 many as 900 contaminants identified contaminants identified as present in indoor air as present in indoor air at ppb or higher.at ppb or higher.

Types of contaminatesTypes of contaminates

VOCs are volatile organic VOCs are volatile organic compounds such as compounds such as formaldehyde (Hformaldehyde (H22CO), CO), benzene (Cbenzene (C66HH66), toluene ), toluene (C(C77HH88), chloroform (CHCl), chloroform (CHCl33), ), acetone (Cacetone (C22HH66O) and O) and styrene (Cstyrene (C88HH88). These ). These come from cleaning come from cleaning products, plastics, products, plastics, perfumes, hair sprays, perfumes, hair sprays, paints, carpet, furnishings, paints, carpet, furnishings, dry-cleaned clothes, dry-cleaned clothes, plywood and other plywood and other products.products.

Biological ContaminantsBiological Contaminants

Molds, fungi, bacteria, Molds, fungi, bacteria, viruses, pollen, and viruses, pollen, and insects. In order to insects. In order to lessen biological lessen biological contaminants, indoor contaminants, indoor humidity should not humidity should not exceed 50%.exceed 50%.

Combustion ProductsCombustion Products

Carbon monoxide, Carbon monoxide, nitrogen dioxide, sulfur nitrogen dioxide, sulfur dioxide, tobacco dioxide, tobacco smoke components, smoke components, and polyaromatic and polyaromatic hydrocarbons such as hydrocarbons such as benzo [a] pyrene.benzo [a] pyrene.

Contaminants generated Contaminants generated by office equipment and by office equipment and supplies such as ozone supplies such as ozone from computer terminals from computer terminals and photocopiers, ethanol and photocopiers, ethanol and methanol from and methanol from duplicating machines, and duplicating machines, and acetone from typewriter acetone from typewriter correction fluid.correction fluid.

Environmental tobacco Environmental tobacco smoke (ETS) smoke (ETS)

It is estimated that It is estimated that 470,000 tons of 470,000 tons of tobacco are burned tobacco are burned indoors each year indoors each year generating both generating both mainstream and mainstream and sidestream smoke.sidestream smoke.

The concentration of The concentration of pollutants include:pollutants include:

1. air exchange rate1. air exchange rate 2. the rate at which 2. the rate at which

pollutants are pollutants are generated indoors.generated indoors.

3. reaction rates 3. reaction rates among indoor air among indoor air components.components.

RADONRADON

Radon is a radioactive, Radon is a radioactive, colorless, odorless and colorless, odorless and tasteless gas formed by the tasteless gas formed by the nuclear decay of U-238 in nuclear decay of U-238 in ground under and around ground under and around buildings.buildings.

When inhaled it can cause lung When inhaled it can cause lung cancer.cancer.

It is measured in picocuries per It is measured in picocuries per liter.liter.

A picocurie is equal to about 4 A picocurie is equal to about 4 nuclear disintegrations per nuclear disintegrations per minute or about 16 nuclear minute or about 16 nuclear disintegrations per minute in a disintegrations per minute in a liter of air.liter of air.

FORMALDEHYDEFORMALDEHYDE Formaldehyde, HFormaldehyde, H22CO is a CO is a

pungent-smelling gas found pungent-smelling gas found both indoors and outdoors.both indoors and outdoors.

It comes from carpets, cabinets, It comes from carpets, cabinets, cigarettes, and insulation.cigarettes, and insulation.

Phenol-formaldehyde and urea-Phenol-formaldehyde and urea-formaldehyde resins are found formaldehyde resins are found in plywood and foam insulation in plywood and foam insulation (UFFI).(UFFI).

UFFI was banned in 1982 but a UFFI was banned in 1982 but a court action reinstated its use in court action reinstated its use in 1983.1983.

Formaldehyde irritates tissue Formaldehyde irritates tissue and is a possible carcinogenic and is a possible carcinogenic (cancer causing) chemical.(cancer causing) chemical.