Thursday, February 12, 2009

Dose Response Functions for Estimating Health Impacts of Air Pollution


Click on the pages to enlarge view.
For a list of references, access the full report
"Estimating the Health Impacts of Urban Air Pollution"
which outlines the methodology for estimating health impacts of air pollution, database of dose-response functions, and example calculations.

Also see "In news: Mortality & Morbidity due to air pollution"


What are the common health impacts of air pollution?

The pollutants listed below mostly experienced in an outdoor setting (from vehicle exhaust, road dust, industrial combustion, garbage burning, and atmospheric chemical reactions), but depending on the location are known to cause significant health damages in indoor settings.

Particulate Matter

PM (for short) of different size fractions consists of dust, mist, metals, and smoke. These particles when breathed in, lodge in our lung tissues and cause lung damage and respiratory problems. The importance of PM as a major pollutant needs special emphasis as
  1. it affects outdoor and indoor environments and in urban and rural settings
  2. it is the most studied pollutant
  3. there is more epidemiological evidence on the PM exposure linking to mortality (premature deaths) and morbidity (like asthma and bronchitis)
  4. more evidence is linking it to climate radiative forcing (via black carbon)
  5. it is the most monitored pollutant, though data is limited from the developing country cities.
Sulfur dioxide

SO2 in the air is caused due to the rise in combustion of fossil fuels, primarily (to name a few) coal and diesel in the power plants, brick kilns, heavy duty vehicles, industries, and generator sets. It can oxidize and form sulfuric acid mist (aka acid rain). SO2 in the air leads to diseases of the lung and other lung disorders such as wheezing and shortness of breath. Long-term effects are more difficult to ascertain as SO2 exposure is often combined with that of PM (in the form of secondary aerosol sulfates).

Oxides of Nitrogen (NOx)

NOx emissions are the fastest growing in most urban centers, primarily from the vehicle exhaust. This gas can make children susceptible to respiratory diseases in the winters. NOx is the one of the main ingredients responsible for making of Ozone.

Carbon monoxide

CO combines with haemoglobin to lessen the amount of oxygen that enters our blood through our lungs. The binding with other haeme proteins causes changes in the function of the affected organs such as the brain and the cardiovascular system. It can impair our concentration, slow our reflexes, and make us confused and sleepy; and leading to premature death.

Volatile Organic Compounds

VOCs are the other main ingredient in the atmospheric formation of Ozone. In bulk, VOCs can cause irritation of the eye, nose and throat. In severe cases there may be headaches, nausea, and loss of coordination. In the longer run, some of them are suspected to cause damage to the liver and other parts of the body


Mostly controlled across the world, as a source from the vehicle exhaust.
Prolonged exposure can cause damage to the nervous system, digestive problems, and in some cases cause cancer. It is especially hazardous to small children.

Tobacco smoke

Tobacco smoke generates a wide range of harmful chemicals and is a major cause of ill health, as it is known to cause cancer, not only to the smoker but affecting passive smokers too. It is well-known that smoking affects the passive smoker (the person who is in the vicinity of a smoker and is not himself/herself a smoker) ranging from burning sensation in the eyes or nose, and throat irritation, to cancer, bronchitis, severe asthma, and a decrease in lung function.

1 comment:

mikesac said...

This is serious when people are ill and they are dyeing.We have to see to it that we reduce air pollution very soon.Our lives are at stake.
Manhattan Air Specialists