Harmattan is caused by north-easterly trade wind, blown from the Sahara Desert over the West African Sub-region. As the Saharan wind passes, it collects or lifts Particulate Matter ranging from ultrafine particles – > 0.1 nano meter in diameter to fine particles – 0.1 – 10 micro meter in diameter; popularly known as Dust. This phenomenon leads to low temperature, reducing radiation from the sun, low visibility and increases air pollution.
Should we be concerned about Harmattan?
Yes. During harmattan air quality worsens as dust get mixed with existing emissions from industries, construction sites, vehicles, fossil fuel burning, etc. The harmattan season poses environment and public health challenges especially respiratory and cardiovascular health problems which may increase morbidity and mortality, hence the need for seasonal mitigation plans.
Fine particles, especially PM2.5,poses the greatest risk as they can travel deep into the lungs and bloodstream and affect the lungs and heart. The sensitive groups are at greater risk to air pollution, these include children and infants, the elderly, people with existing respiratory diseases (asthma, Chronic Obstructive Pulmonary disease etc.), people with ischaemic heart disease (angina pectoris), expectant mothers etc. Other short-term health effects include irritation of the eye, nose and throat, coughing, sneezing, shortness of breath, etc.
What can Government and individuals do?
Below are some mitigation measures that can be taken to reduce environment and health impact of harmattan:
1. Government should enforce “Construction of Dust Emission Mitigation Measures” for all site dust management: This should be stated in the environmental management plan (EMP) and Construction Environmental Management Plan (CEMP) for implementation in all construction companies.
2. Sustainable Agricultural Practices. Educate and sensitise farmers on minimum tillage practice, etc. to keep soil covered with plant residues. Better soil management techniques to reduce/control wind erosion in cropland, provide protective barriers.
3. Sustainable landscape management of cropland, grassland, dune fields, mines and building sites and establishment of vegetation cover tree crops/shrubs.
4. Early warning signs. Government should provide early warning signs, forecast and enlightenment programmes for the public to take personal care and prevent exposure especially areas with higher vulnerability. This is where Air Quality Monitoring becomes important.
Personal Care Measures:
1. Avoid/Reduce outdoor activities at peak hours especially sensitive groups (i.e., children, elderly, people with existing respiratory diseases such as asthma etc.)
2. Practice regular sprinkling of water to reduce dust emission in your surrounding
3. Wear face/Nose mask during outdoor activities
4. Close your windows/doors to prevent outdoor polluted air.
5. Drink plenty of water regularly to keep hydrated.
6. Keep warm.
7. Wash your eyes with clean water if you feel irritated.
8. Apply moisturising lotion/cream to keep your skin moisturised.
9. Seek medical help if you feel sick.
10. Keep updated with daily weather and air quality forecast.