Level and Health Risk Evaluation of Heavy Metals and Microorganisms in Urban Soils of Lagos, Southwest Nigeria

Abstract

Heavy metal and microbial pollution of the environment are linked to the increasing prevalence of diseases worldwide. Accordingly, this study assessed the safety of urban soils in Lagos, Nigeria, with regard to the levels of lead (Pb), nickel (Ni), cadmium (Cd), copper (Cu), chromium (Cr), zinc (Zn), and microorganisms. Soil samples were collected from Iwaya, Makoko, and Ilaje areas of the city and subjected to atomic absorption spectroscopy (AAS) and microbiological examinations using standard protocols. The mean values obtained for the heavy metals and microorganisms were compared with the World Health Organization (WHO) permissible limits. The average daily oral ingestion (ADOI), average daily dermal ingestion (ADDI), and the hazard quotient (HQ) of the heavy metals were also calculated. The AAS indicated that the soils in the three areas contained non-permissible levels of the evaluated heavy metals, except Cu and Cd. The microbiological examinations also showed that the soils contained abnormal levels of heterotrophic bacteria (HB), hydrocarbon utilizing bacteria (HUB), heterotrophic fungi (HF), and hydrocarbon utilizing fungi (HUF). The ADOI of the heavy metals in the three areas were above the recommended levels, while ADDI were normal. Moreover, the HQ of oral ingestion of each heavy metal except Cr was greater than one, while the HQ of dermal ingestion of the heavy metals was less than one. These findings suggest that the soils could predispose the residents in the areas to diseases. Thus, there is a need for regular environmental sanitation and environmental pollution control in the areas, and personal hygiene.

Effects of Pit Latrines on Borehole and Well Water in Maryland, Lagos, Nigeria

“…19 It is, however, one of the world's most populous and fastest growing cities. 15 Lagos is estimated to have a population of 17.5 million people. 19 Lagos is bordered by Ogun State on the north and east, and the Atlantic Ocean's shoreline and the Republic of Benin on the south and west, respectively.…”

“…Water samples were analysed for total bacteria, coliforms, and fungi using the procedures used by Yahaya et al 6 The total bacteria count was determined using filtering aliquots of 50 mL from each sample by a 0.45 m paper filter and placing the filter on a nutrient agar plate, and incubating it at 37 °C for 24 hours. The total coliform counts were determined by the same way for the bacteria, but the filter was placed on lauryl tryptose broth and incubated aerobically at 45 °C for 24 hours.…”

“…5 Contamination of water sources can occur from natural processes such as leaching of rocks or from the uses mentioned earlier. 6 Pit latrines which are the most common facility for human excreta and urine disposal in several regions of the world, may be a source of water pollutants. 7,8 Pit latrines are often utilized by low-income earners because they are the simplest, cheapest, and most efficient excreta disposal method within their reach.…”

“…13,14 Heavy metals are toxic, non-biodegradable, and have been implicated in several health hazards, including respiratory, genetic, and hematological diseases, as well as skin, eye, and brain damages. 15 Overall, the adverse effects of the pollutants suggest that groundwater sources such as boreholes and wells in places with a high density of pit latrines need to be monitored regularly.…”

Interaction of Red Cell Indices and Blood Group in Diabetic Patients above 50 Years of Age

“…ABO blood groups are hereditary and are controlled by a gene on chromosome nine known as the ABO gene or immunoglobulin [10]. Thus, some cases of diabetes may be genetic [11,12].…”