Bush burning is the usual practice in Nigeria and many parts of West Africa done as part of pre-planting activities. It usually done in the dry season or harmattan period the region is currently experiencing. This practice however has untold effects on the health of those who practice it and vulnerable groups such as children, pregnant women and the aged in the surrounding communities.
Professor Godson Ana, an environmental health scientist, and National President, Environmental Health Officers Association of Nigeria (EHSAN), explained to Ecoscope that gaseous materials and particulate matter are released into the atmosphere and pollute the air. According to him, the gases released are oxides of carbon (carbon dioxide and carbon monoxide), nitrogen and sulphur, depending on the types of materials being burnt.
The combustion of plastic materials that may be found in the bushes will also release dioxins which are cancer causing agents and, polycyclic aromatic hydrocarbons (PAHs) that are bye-products of incomplete combustion.
Volatile organic matter and biogenic materials that are burnt release particles (particulate matter) of different sizes.
Health implications on perpetrators
There are systemic and non-systemic health implications for those doing the burning, Professor Ana said. “Their eyes are exposed to the debris, to the gaseous materials and to the particulate matter. They can have eye problems like retina damage, excessive lacrimation (tear production) and issues related to cataract may precipitate, depending on the exposure over time.
For the skin, people involved in bush-burning may have contact dermatitis, lacerations, oedema, and depigmentation of the skin, Professor Ana of the Faculty of Public Health, College of Medicine, University of Ibadan, added.
“The biggest problem has to do with the respiratory pathway. For exposure to the oxides of carbon – carbon monoxide is a killer gas. It is an asphyxiant gas because it competes with oxygen in the binding side of haemoglobin. Haemoglobin is the oxygen carrier (in the blood). It knocks off the oxygen and binds to the haemoglobin. So exposure to carbon monoxide is deleterious to their health.
“Again, they will be exposed to large amounts of particulate matter and that will affect the pulmonary function of the exposed person.”
He said when the pulmonary function is compromised it will cascade into a number of events like breathlessness, wheezing, and aggravate issues for people that are asthmatic.
“The exposure to other gases that are carcinogenic in nature like dioxins and PAH can precipitate into cancer over time. The effects will be chronic, but it will take a long period of latent time to manifest, depending on the dose of exposure and the duration.”
Implications for people in surrounding communities
What then is the lot of persons living in the surrounding communities where bush burning occurs?
The EHSAN national president said the health effects are similar to what obtains for the perpetrators of bush burning. “It is a similar scenario. In this case, the number of persons affected will be more. Depending on the degree of susceptibility, you could talk of increased hospitalisation for the category of people that inhabit those places.”
“Looking at the social demographics,” Professor Ana said, “you will have vulnerable populations that inhabit those places. The vulnerable groups include children coming down with respiratory problems.”
He explained that “During harmattan season, when the dust content is high and there is dry air, and the peak rainy season when there is cold air, these are the two periods we have increased hospitalisation especially among children under five. So, in communities exposed to bush burning, the respiratory conditions of the children there will be compromised.”
He added that the elderly is another category of vulnerable groups. For this category he noted that adverse respiratory conditions would also arise.
“Another group will be pregnant women, because these are people whose immunity is kind of challenged because of certain peculiar conditions.”
These vulnerable groups are highly at risk. He said more women than men would develop respiratory conditions in the surrounding communities where bush burning occurs, because they often do more domestic activities at home, which implies longer exposure to polluted air in the community.
‘Reproductive health is at risk also’
Apart from respiratory, eye and skin challenges for the community, reproductive health is also at risk. “The constituents of the pollutants can also inhibit the reproductive cycle in terms of inhibiting the hormones like oestrogen. It can affect the women’s menstrual cycle. Depending on the what is the product of the combustion that they are inhaling, it can cause some inhibition that will affect the hormonal cycle.”
Any alternatives?
Engage in more environmentally friendly farm practices is Professor Ana’s advice. As one alternative, farmers could clear the farms, and set aside organic components of the debris for mulching. “In other parts of the world outside Nigeria and in some parts of Africa, they don’t do bush burning to cultivate. They clear the bush and try as much as possible to put aside plant materials and they constitute mulch, rather than burn. Also, some of those materials can constitute renewables. Recycling can be done as some of these materials are used as agro bye-products. There are lots of ways to engage those materials rather than burn,” he concluded.
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