Indoor Pollution, Human Health and Technology

Wendy GeiseESP 6130 Science and Technology for Environmental SecurityMay 15, 2006

Overview

• Why should we care about indoor pollution?

• Categories of indoor pollution

• Health impacts

• Solutions and suggestions (some technical, some not)

Why should we be concerned about indoor pollution?

World Health Report’s estimates of death and ill-health (DALYs) from leading risk factors in the year 2000 Source: Smith 2000

There are four principal categories of indoor pollution

• Combustion Products

• Chemicals

• Radon

• Biological

Combustion generated pollutants are a major issue in developing countries

• Half the world’s population and 90% of rural households rely on unprocessed biomass including wood, dung and crop residues

• Indoor concentrations of particles can be 10-100 times higher than US EPA guidelines for daily exposures

• Women and children exposed 3-7 hours per day over many years

• Increases risk of pulmonary and respiratory disease - leading cause of death in children under 5 years

• Additional association to low birth weights, TB, throat cancers, cataract and lung cancer (from coal)

Source: World Health Organization 2000

Africa and Asia are the most highly impacted

The estimated cost to improve indoor pollution in developing countries is $2.5 billion

• China has implemented over 200 million stoves to reduce indoor pollution

• Kenya and Sri Lanka nearly 1 million each

Source: Practical Action 2006

Indoor exposure to chemical sources is a concern in developed countries

• 80,000 chemicals compounds being made worldwide

• US EPA approves 2,000 additional each year

• 80% approved in less than 3 weeks

• Less than 10% have been tested for human and environmental safety

• 43% lack basic toxicity data

• Researchers estimate 5-10% of chemicals in production could be carcinogenic

• EPA study found indoor exposures to carcinogenic substances 5-70 times higher than outdoors, some levels were high enough to qualify as a Superfund site

Source: Naturally Clean 2005

Chemical sources are found throughout the modern house

What are the human impacts?• Accumulation in fat cells, muscles, bones, brains and organ tissues

• Body burden - According to EPA, every man, woman and child in US has at least 700 pollutants in their bodies

• Forty-four percent of men and thirty-nine percent of women will get cancer in their lives – 24% increase in 30 years

• Women who work in the home have 55% higher risk of cancer and respiratory disease than women who work outside the home (Sterling 2001). Researchers have found that many chemicals in household cleaners cause hormone disruption (new area of study)

• Exposure to VOC’s linked to higher rates of asthma

• Total indoor hydrocarbon concentration significantly related to “sick building syndrome” (Norback, 1990)

• 15-30% of Americans report sensitivity or allergy like conditions from exposure to chemicals

• New condition called Multiple Chemical Sensitivities from a single high exposure event or repeated low-level exposure to chemicals affects 5% of population

Source: Naturally Clean 2005

Recent legislative proposals suggest a more precautionary approach• Current lax regulations allow chemicals to be released into the environment and

routinely used in consumer products on the assumption that they cause no harm

• REACH (Registration, Evaluation and Authorization of Chemicals) in EU– Assess the estimated 100,000 chemicals currently on the European market– It will permit the continued use of these most hazardous chemicals even if a safer alternative

is available.

• US Child, Worker and Consumer Safe Chemicals Act – 2005 proposed legislation following REACH in EU

• Strategic Approach to International Chemicals Management (SAICM), the initiative is a

voluntary UN agreement that deals with risk assessments of chemicals and standardized labeling – 2006

– Persistent, Bioaccumulative and Toxic substances (PBTs)– Very Persistent and Very Bioaccumulative substances (vPvB)– Chemicals that are carcinogens or mutagens or adversely effect reproductive, endocrine,

immune or nervous system, including all forms of asbestos; – Persistent organic pollutants (POPs)– Mercury and other metals of global concern

Source: EurActiv 2000-2005

Exposure to radon is also greater indoors

• Radon is an odorless gas that comes from natural breakdown of uranium in nearly all soils

• It can also be found in well water

• 2005 - The Surgeon General of the United States issued a Health Advisory warning Americans about the health risk from exposure to radon in indoor air

• Two studies show definitive evidence of an association between residential radon exposure and lung cancer. 

• The World Health Organization (WHO) says radon causes up to 15% of lung cancers worldwide

• Smokers have higher risks

• US EPA suggests all homes should be tested for radon

Source: US EPA

Trained contractors can be hired for radon mitigation

• Vent/pipe system and fan are installed to pull radon gas from beneath the house and disperse outside the home

• Foundation cracks are sealed

• Costs range from $800 to $2500 for contractor to install

Source: EPA Radon Citizens Guide

Homes also can contain many biological contaminants

Types:• Bacteria• Mold/Mildew• Viruses• Animal dander• Dust mites• Pollen

Health Effects:• Allergic reactions• Asthma• Infectious disease• Disease causing

mycotoxins from molds and mildews

Steps to control indoor biological contaminants

• Maintain relative humidity between 30% - 50% year round (whole house air purifier/dehumidifiers cost up to $2200)

• Install and use exhaust fans that are vented to the outdoors in kitchens and bathrooms and vent clothes dryers outdoor

• Ventilate the attic and crawl spaces to prevent moisture build-up  • Thoroughly clean and dry water-damaged carpets and building materials

(within 24 hours if possible) or consider removal and replacement

• House dust mites, pollens, animal dander, and other allergy-causing agents can be reduced, although not eliminated, through regular cleaning  

– People who are allergic to these pollutants should use allergen-proof mattress encasements, wash bedding in hot (130° F) water, and avoid room furnishings that accumulate dust, especially if they cannot be washed in hot water

• Take steps to minimize biological pollutants in basements

Source: US EPA

The basic strategy for controlling indoor pollution

• Source control

• Ventilation improvements

• Air cleaners– Activated carbon (removes

some but not all VOC’s, gases)

– HEPA filtration (developed by Atomic Energy Commission to remove radiation particles from nuclear labs)

– Most effective is a combination HEPA/Activated carbon

Questions?