A recent declaration by the cancer research agency of the World Health Organization: The International Agency for Research on Cancer (IARC) has presented the need to revisit the state of air quality in major cities. A report by the expert panel of the IARC stated that “The air most people breathe has become polluted with a complicated mixture of cancer-causing substances, making air pollution the most important environmental carcinogen ahead of second hand cigarette and cigar smoke.”
Although major causes of air pollution such as fossil fuel combustion have been previously considered carcinogenic, there wasn’t enough scientific evidence to conclude that air pollution is entirely carcinogenic. Presently, a significant amount of scientific studies have been able to establish a link between air pollution and lung cancer deaths worldwide. It was based on this premise that the IARC made its recent declaration.
Major cities in developing economies are commonly confronted with the problem of poor air quality. Unsustainable environmental management practises and inefficient energy use have been reported as the major cause of this air quality problem.
Nigeria is one of the emerging economies in Africa, attracting investors from across the globe. As businesses are booming in major cities of this country, air pollution is increasing with a growing demand for essential services such as transportation and power generation. Air quality reports for major Nigerian cities indicate that the concentration of particulate matter and other air pollutants exceeds national and international safe limits.
In the light of the recent IARC declaration, the reported state of air quality in major Nigerian cities raises major concerns about the future health of the country’s growing urban population. This calls for urgent action to address those sources of air pollution, while protecting the inhabitants of these cities from future respiratory-related cancer outbreaks. Hence, the objective of this article is to present possible innovative means of health promotion through air quality improvement in major Nigerian cities.
Current air quality state
In July 2013, the total population in Nigeria was recorded at 170 million people. Poor rural infrastructure and unemployment has led to an increasing trend in rural-urban migration. As a result, a greater percentage of the country’s active workforce lives or works in major cities like Lagos, Kano, Ibadan, Kaduna, Port Harcourt, Benin City, Maiduguri, Zaria, Aba and Ilorin.
These cities serve as the hub of the country’s economic activities, thus population is on the rise, making them the ten most populated cities in Nigeria (Rhett Butler, 2009). The delivery of basic services like transportation to meet the daily needs of the inhabitants of these highly populated cities introduces a substantial amount of pressure on natural resources such as air and water.
Such pressure leads to the reduction in the quality of these natural resources, thereby causing diseases to humans. Hence, air quality is said to be poor or polluted when toxic biochemical or particulate matters are introduced into the atmosphere through anthropogenic activities or natural disasters.
Anthropogenic activities are the major causes of air pollution in most major cities (Tawari & Abowei, 2012). The health implications of air pollution are more critical than that of any other environmental component because unlike waterborne diseases which can be prevented by purifying the contaminated water before consumption, airborne diseases are more lethal as humans only have very minimal control over their exposure to contaminated air.
Air quality in major cities across the country is a well studied subject. Okunnola et al, (2011) assessed the air quality along some busy traffic roads in one of the major Northern Nigerian cities and revealed that traffic emissions within Kano metropolis were not within safe limits because most of the air pollution components monitored during the study were above the safe air quality limits recommended by the United States Environmental Protection Agency (USEPA).
Similar cases have been observed in other major Nigeria cities like Lagos, where air pollution components from traffic and incineration of solid wastes have contributed to air pollution that is 500% higher than safe levels established by the World Health Organization (WHO). Other studies have also examined the distribution of air pollutants and the possible health implications in major Nigerian cities.
One study by Efe, (2008) confirmed that the annual mean ambient particulate air pollution in 17 major cities in Nigeria was five times higher than the WHO 2005 safe limit of 20µg/m3 for particulate matter. The study also showed that the northern cities have generally higher concentrations of particulate matter, with annual mean of 132µg/m3 in Maiduguri, 130µg/m3 in Sokoto, 128.3µg/m3 in Bauchi and 128.1µg/m3 in Kano respectively, while the southern cities recorded values that span 118µg/m3 in Port Harcourt to 122µg/m3 in Warri and Lagos. The middle belt area has values of 123.9µg/m3 in Yola, Minna and Jos to 124.3µg/m3 in Ilorin. This study further stated that the high concentration of particulate matter recorded in most of these Nigerian cities has resulted in significant prevalence of respiratory and eye infections.
In 2007 the WHO estimated that air pollution contributed to 14,700 deaths in Nigerian cities. Based on this statement, Ekpenyong et al (2012) initiated a study to ascertain if intercity transporters and commuters within Uyo metropolis were facing adverse respiratory health effects due to exposure to outdoor ambient air pollution. Their study found that most people living within the metropolis received their daily air pollution dose while commuting to work, irrespective of transportation mode.
Such exposure leads to respiratory and pulmonary function impairment in the exposed individuals, making air pollution a major threat to human life within the metropolis. These studies have provided enough evidence to support the fact that the inhabitants of major Nigerian cities are highly vulnerable to respiratory disease such as bronchial asthma, emphysema, chronic bronchitis and lung cancer.
Notwithstanding this evidence, little and in most cases nothing has been done to implement the recommended solutions for cleaner air in these Nigerian cities. Thus, there is need for the introduction of a new paradigm that will involve private sector investment in air pollution control technologies.
Considering that Nigeria is one of African’s largest developing economies, foreign investors can explore business opportunities that will lead to better air quality in major Nigerian cities – especially Lagos, which forms one of the largest economic hubs in Africa. Air pollution control presents an opportunity for innovative technology investments in Nigeria’s major cities. Identifying such opportunities will require reviewing the major sources of air pollution and elucidating how innovative technology investments can help eliminate air pollution from these sources.
Major air pollution sources
An article published in the Foreign Policy blog of the Washington Post summarised the major sources of air pollution in Nigerian cities to include automobile emissions due to the poor quality of cars; maintenance and age of motor vehicles; traffic gridlock during peak periods; low grade leaded gasoline; inefficient use of fossil fuels; industrial power generators and indiscriminate incineration of municipal solid wastes.
The contribution of automobile emissions to air pollution in Nigerian cities has followed an increasing trend due to per capita increase in vehicle ownership. For instance, the government’s agency for road transportation safety reported an increase in the number of registered vehicles between 1999 and 2004 following the implementation of new government policy that favoured the importation of used vehicles into the country.
This also made Nigeria the destination for North American and European used vehicles that had failed emission standards tests in their country of origin. The catalytic converter in most of these imported cars is damaged after few months of use in Nigeria due to the high lead content of the gasoline available in Nigerian gas stations. In cases where the cars operate on carburetor engines, the catalytic converter is removed to enhance fuel economy and avoid engine overheating because the carburetor is incapable of precise fuel-air mixture control.
Following removal of the damaged catalytic converter, the vehicle becomes a major source of air pollution due to direct release of partially combusted hydrocarbon compounds from the exhaust. This problem is exacerbated by the fact that there isn’t any vehicle emission standard test stipulated by the government for vehicles driven on Nigerian roads. For this reason, the sight of vehicles, especially heavy duty diesel trucks emitting large amounts of soot in traffic gridlock is commonplace in major Nigerian cities. This explains how inhabitants of these cities receive their daily air pollution dose while commuting – irrespective of transportation mode.
The introduction of auto rickshaws as an alternative means of transportation in most Nigeria cities has contributed significantly to automobile air pollution and commuters’ exposure to air pollutants. The engines of these imported auto rickshaws are inefficient in combusting the grade of gasoline that is locally available in Nigeria. As a result of incomplete combustion of gasoline, the auto rickshaw engines produce a lot of soot which is inhaled by commuters seated behind in the partially open vehicle. This source of air pollution and pollutant exposure is of critical concern since a significant number of commuters prefer to use the auto rickshaw because it appears to be a faster means of transportation, especially as the drivers tend to manoeuvre through gridlocked traffic during rush hours.
Electrical power generation through gasoline and diesel generators is another source of air pollution in major Nigeria cities. Since her independence in 1960, Nigeria has been faced with the challenge of providing uninterrupted public electric power supply from the national grid. As a result of this inefficiency in public power generation, industries and businesses rely on private electric power generation using diesel powered generators.
A similar trend is also observed among households as every average Nigerian household has its own electric power generator set. In most cases, these power generators are mounted proximal to the house, allowing the pollutants from the exhaust to easily disperse around the house through windows and open areas in the building. The soot emitted from these generators contributes significantly to air pollution in the residential areas of Nigerian cities.
Indiscriminate open incineration of municipal solid wastes on dumpsites is a common unsustainable means of municipal waste management in most Nigerian cities. The proximity of these dumpsites to residential vicinities supports the notion that unsustainable waste management is a major cause of air pollution in Nigerian cities and exposes city dwellers to toxic airborne substances.
The type of air pollutants released through municipal waste incineration depends on the composition of the waste, age of the dump and intensity of the incineration heat. Tawari & Abowei (2012) reported that the air within refuse burning sites is inundated with Volatile Organic Compounds, Carbon Oxides, Sulphur Oxides, Nitrous Oxides, Total Hydrocarbons (THCs), as well as various classes of toxic and hazardous compounds such as Polycyclic Aromatic Hydrocarbons (PAHs), dioxins, PCBs (Polychloro Biphenyls) and heavy metals such as lead, nickel and mercury. Most of these substances have been implicated for their role in causing respiratory organ impairments, especially lung cancer.
Previous studies have made some recommendation on how these major sources of air pollution can be eliminated from Nigerian cities. Some of the solutions that were recommended for the improvement of air quality include implementing emission control technologies in industrial and power generating plant smokestacks; replacing polluting motor vehicles with low emission and zero emission alternatives; refining gasoline to get the lead out; and substituting cleaner fuels for generating power, heat and electricity.
Over the years these recommendations have not been adopted, due to lack of commitment on the part of the government and also because of the high cost of their implementation. Since the government has failed to address these problems, private sector intervention through capital investment in innovative technologies is a more realistic alternative for eliminating these major sources of air pollution.
An innovative approach
The most effective strategy to mitigate the impact of air pollution on the urban population will involve providing immediate means of protecting the people from existing polluted conditions while developing means of eliminating the sources of air pollution in the urban area. This approach has been adopted in major polluted cities like Shanghai, China, where the traffic police department has distributed nasal smog filters to some officers in an effort to protect these outdoor workers from air pollution in the city.
The nasal smog filter is a nostril-sized pollution screen which fits discreetly inside the nostrils, allowing the individuals wearing them to speak without obstruction. This type of air filter can be produced locally in Nigeria, and considering the population of the major Nigerian cities, a large consumer market exists for this product.
Since IARC has identified air pollution as the most important environmental carcinogen, public health promotion practises should involve capital investment in technologies that will prevent the outbreak of airborne impairments in urban environments. Thus, cancer prevention research organisations can facilitate the introduction of nasal air filters to individuals living in urban environments where air quality is compromised.
Adequate research efforts should be invested in portable nasal filters, especially since most people find it difficult to wear the conventional nose mask which has been made unpopular due to its conspicuous nature. Public transport drivers, outdoor workers and regular rickshaw commuters could be used to test the effectiveness of the nasal air filter before introduction to the general public.
Another approach that can be adopted to promote health through air quality improvement is the elimination of air pollution sources. Urban transportation has been implicated as the major source of air pollution in major Nigerian cities, but considering that transportation is a vital aspect of economic activities, eliminating it is impossible and replacement with a more environmentally friendly alternative seems unrealistic due to the failure of governments in Nigeria.
While waiting for the government to implement basic vehicle emission safety standards for every vehicle driven on Nigerian roads, the introduction of exhaust tailpipe filters can act as an alternative means of curbing emissions from transportation sources. Exhaust filters are made of biochemical materials that break down air pollutants as they exit through the exhaust pipe. Although not fully developed, the exhaust filter technology has been in existence for a while and can be adapted to fit the needs of transportation air pollution control in Nigerian cities.
The major challenge associated with this technology is the need to replace the filters bimonthly. Notwithstanding, recycling incentives can be introduced to help encourage replacement of expired exhaust filters. Introduction of this type of product will require extensive publicity, with special focus on educating the people about the health implications of inhaling unfiltered emissions from vehicle exhaust. The exhaust filter technology can also be extended to power generator exhaust to help curb air pollution from this source.
Replacement of diesel and gasoline power generators with indigenous solar technologies is another area that requires capital investment. Following years of disappointing and inefficient distribution of electricity from the national grid, Nigerians are eager to embrace alternative sources of power generation, especially those from renewable energy sources that do not require payment of monthly utility bills.
In the light of this, the first integrated renewable energy powered model village in Nigeria has been commissioned in one of the northern states – Sokoto. The system was designed to provide the energy needs of a village with 1,000 inhabitants. Organisations like The Global Village Energy Partnership (GVEP) are on the right track by helping the growth of small energy business in Africa. Their work led to the discovery of a man from rural Kenya who developed low cost wind turbines from locally available scrap metals with the capacity to produce between 50W and 1,000W of electricity. Innovations like this should be encouraged through technical support and capital investment.
Creating a functional municipal waste management service will solve the problem of pollution from solid waste incineration. The engagement of about 5,000 scavengers in dumpsites within major cities like Lagos is an indication that there is a booming market for waste recycling in Nigerian cities. If waste sorting is implemented, organic waste can also be channelled towards energy generation. This waste to energy technology has been in practise in Japan as a way of improving their waste disposal problems in highly populated cities.
Through a systematic review of contemporary air quality research in major Nigerian cities, this article establishes that the air in most Nigerian cities is polluted with contaminants generated mainly from transportation emissions and other anthropogenic sources.
Over the years, various air quality studies in Nigerian cities recommended possible policy and management practises that would help achieve cleaner air in the cities, but the government and stakeholders have failed to implement any of the recommendations.
Following the recent IARC declaration that air pollution is the most critical source of carcinogens around the world, the need for immediate action towards eliminating the sources of air pollution in Nigerian cities has led to the appeal for capital investment in technologies that can improve their air quality.
Published: 27th Nov 2013 in AWE International