Indoor and outdoor pollution and asthma

Written by Written by Dr Farouk Jooma
Endorsed by ALLSA and the SACAWG.

Introduction

• As the tempo of industrial and agricultural activities increase around the world, and as human populations continue to grow, (particularly in the world's poorer communities) so the number of children exposed to environmental pollutants increases
• Children are exposed to the same range of environmental pollutants as adults but the effects of this exposure seem to be greater
• The exact role of air pollution in asthma is still not clear and is therefore controversial.
• Pollution is thought to be important in the development of asthma, it causing asthma to persist and it causing attacks of asthma.
• Pollution can occur inside the home (indoors) and obviously outdoors:
  • Indoor pollutants are: cigarette smoke, cooking fuels and chemicals.
  • Outdoor pollutants are industrial effluent, motor vehicle exhausts and agricultural chemicals

Indoor pollution

Cigarette smoke

• Smoking is the commonest indoor pollutants and it affects all people in contact with it

• Exposure to cigarette smoke is the most important environmental risk factor for asthma (and other chest complaints) in children

• Mothers who smoke (especially when they are pregnant) increase risk of their child developing asthma

• Children with asthma whose parents smoke have more episodes of acute asthma, more respiratory tract infections and six times more ear infections than children whose parents do not smoke

• Young children are particularly at risk as they cannot get away from the smoke filled environment. Older children are away from home more often as they are at school in the morning and frequently play outside in the afternoon

• Homes of asthmatics MUST be smoke free. Smoking in another room or when the child has gone to bed will still affect the child as it seems that it is not the smoke itself but the chemicals that are left behind. These can take up to 2 years to clear after stopping smoking!!

 

Other indoor pollutants

• Other potentially troublesome indoor pollutants are fumes from gasburners (stoves and heaters), insecticides, paints, solvents or cleaning materials.

• Poor ventilation plays an important role in worsening this problem. The gases from gasburners such as nitrogen dioxide, carbon monoxide and sulphur dioxide can reach toxic indoor levels in poorly ventilated homes. They can cause an asthmatic attack and also increase the risk of chest infections, especially in young children.

• Cosmetic agents are also known to irritate the airway of asthmatics. perfumes, fumes from paint, cleaning supplies, nail polish remover or hair spray are the common agents. The strong odour from these chemicals makes breathing uncomfortable and can worsen existing allergies

 

Outdoor pollution

Out door pollution entails an exposure to a large and variable mix of pollutants. There are numerous naturally occurring and man-made substances capable of causing reactions in individuals. Some act as allergens and others as irritants.

 

Outdoor pollution consists of

• Gaseous substances like sulphur dioxide, nitrogen dioxide and ground level ozone
  • Sulphur dioxide (SO2) is produced when coal is burned. The biggest industrial contributor are power stations. High SO2 levels also occur in areas where coal is used extensively for domestic heating and cooking. A number of studies have shown an association between increased visits to the emergency room for asthma and high levels of air pollutants especially SO2. These visits occurred especially in the winter months. It has also been shown by laboratory experiments that inhalation of SO2 by asthmatics can cause a significant degree of wheezing at concentrations lower than those which affect non-asthmatics
  • Nitrogen dioxide (NO2) is in motor-car exhaust fumes. Greatest exposure however occurs indoors in homes with gas cookers and gas heaters. There is disagreement on the importance of NO2 in asthma. It may irritate the airways making them more prone to other pollutants.
  • Ground level ozone is produced by a chemical reaction in the air between pollution and sunlight. It should not be confused with the ozone high up in the stratosphere which protects us from harmful ultra-violet light. Ground level ozone also acts as an irritant to airways, reducing their ability to work properly and worsening allergic reactions
  • Volatile organic compounds like benzene
  • Metals such as copper, lead

• All of these compounds are emitted by man-made sources

• Environmental pollution is not restricted by geographical boundaries. Industrial effluent released into the atmosphere or rivers in one country may affect people in an adjacent country. A typical example of this is the Chenorbyl disaster.

 

 

Recommendations

Tobacco smoke Parents must stop smoking especially at home Ban smoking from your home No smoking during pregnancy Avoid passive smoking at all costs hence smoking in public places should be banned

Fire places and woodburning stoves Ensure that flues, chimneys, stove pipes and ventilation systems are tight-fitting, well maintained, open and close easily and are used properly Alternative fuels that do not pollute the environment has to be considered

Strong odours and Chemical fumes

• When using strong smelling products, always follow instructions. Keep windows and doors open to circulate the air. Filter face masks can help trap particles
• Schedule the use of these products when the irritant sensitive person is out of the house for a few days
• Store as few toxic products as possible. Eventually the fumes may leak
• Tell your families, friends and co-workers if strong perfumes bother you and ask them not to wear it around you
• Ensure that the air conditioner filters are cleaned and replaced regularly

 

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Copyright: Allergy Society of South Africa.
Written by Written by Dr Farouk Jooma
Endorsed by ALLSA and the SAWGCA.

This information sheet is obtainable from:

ALLSA P.O. Box 88 Observatory, 7935 Cape Town, R.S.A.

Afrikaner Bull Background: Gemsbok