Possible Health Risk due to the Environmental Exposure of High Levels of Lead in Exhaust Soot of Automobiles in Parts of Accra, Ghana

Abstract

Internal combustion engines produce soot as a result of incomplete gasoline and diesel combustion.  Leaded exhaust soot emitted into the atmosphere has serious health and environmental concerns. Lead has been outlawed as an automotive gasoline additive in most countries including Ghana because of its cumulative toxicity in humans especially children and damaging effect on catalytic converters in automobiles. Nevertheless, leaded fuels are apparently being produced, imported and used illegally in some countries as octane rating booster because of its profitability. Refined gasoline and diesel are imported into Ghana through bulk oil distribution firms. This preliminary study assessed the level of lead in automotive exhaust soot from randomly selected automobiles in parts of Accra. Exhaust soot samples obtained from ten diesel and ten gasoline automobiles were collected for analysis of its lead concentration using atomic absorption spectrophotometry. The results showed the presence of lead in 4(40%) and 10(100%) of the randomly selected diesel and gasoline vehicular exhaust soot respectively. The concentration of lead in the exhaust soot of diesel-powered automobiles ranged from 0.060mg/kg to 0.435mg/kg and that of the gasoline-powered vehicles recorded values ranging from 0.195mg/kg to 2.055mg/kg. With this rather high level of lead in the vehicular soot, it could be concluded that the exhaust soot can be a significant source of lead in the atmosphere in parts of Accra. Lead exposure is known to cause debilitating developmental and neurological effects in children and cardiovascular effects in adults. The high levels of lead in the exhaust soot may be attributed to the possibility of lead additives in the gasoline and diesel used by those automobiles. Regulators of the petroleum downstream industry such as the National Petroleum Authority must routinely test for lead in imported refined petroleum products and enforce the ban on the importation, sale and usage of the outlawed leaded fuel in Ghana. Further studies should be conducted on the levels of lead in air and blood lead levels in fuel dispensers, fuel tanker drivers and fuel loading workers of bulk oil distribution firms.

Keywords: Lead, Exhaust, Soot, Gasoline, Automobile