Monte Carlo approach to risks assessment of heavy metals at automobile spare part and recycling market in Ilorin, Nigeria

Abstract

This study evaluates the sources and health risks associated with heavy metals in Ipata spare part market in Ilorin, Nigeria. Soil and water samples were collected within and outside the market for heavy metal (As, Pb, Mg, Mn, Cd, Cr, Cu, Zn, Fe and Ag) analysis using Atomic Absorption Spectrometry. The results indicate that all the heavy metals analyzed show higher concentration within the recycling market than the control location. The concentration of heavy metals at the market decreases with an increasing depth between 0 and 50 cm and appears to be stable below 50 cm of the soil depth. All the Hazard Indices (HI) estimated for the soil samples are less than one (< 1) which is the standard set by USEPA, whereas, the Hazard Index (HI) for the water samples within the station is greater than 1. The Incremental Lifetime Cancer Risk (ILCR) for soil samples ranged from level I to level V, while that of water samples ranged from level VI to Level VII based on Delphii method of classification. This shows that the main lifetime cancer risk occurs through the water exposure pathway. Similarly, according to the mean, P5% and P95% cumulative probability using the Monte Carlo simulation, the ILCR is above the acceptable range of 1.00E−6 and 1.00E−4. All the pollution indices reveal that the significant pollution at the park is more of anthropogenic than pedogenic and lithogenic. Therefore, the market is contributing immensely to environmental pollution which may lead to unforeseen danger to human health.

Investigation on the Storage Stability of Packaged Water Commonly Produced in Ilorin Metropolis, Kwara State, Nigeria

“…According to the risk classification system assembled by International Agency for Research on Cancer (IARC) and WHO, among the heavy metals analyzed in this study, Pb and Cr were human carcinogens, and their carcinogenic slope factors are 8.5 × 10 −3 and 0.5(mg/L/day) -1 respectively (Orosun et al 2020). The carcinogenic risk estimation gives an index of risk or possibility of an aimed people to develop cancer of several types as a result of the ingestion of the carcinogens in the drinking waters over a projected lifetime (Orosun et al 2020;Isinkaye2018). Incremental Lifetime Cancer Risk (ILCR) that presents the carcinogenic risk was calculated using equation ( 13) (Orosun et al 2020;Isinkaye2018).…”

“…The calculated Chronic daily intake (CDI) in proportion to oral reference dose (RfDoral) of the selected heavy metals branded as target Hazard Quotient (HQ) (Orosun et al 2020;USEPA 2001), is generally utilized to highlight the severity of the non-carcinogenic risks. The formula is given by USEPA as;…”

“…The carcinogenic risk estimation gives an index of risk or possibility of an aimed people to develop cancer of several types as a result of the ingestion of the carcinogens in the drinking waters over a projected lifetime (Orosun et al 2020;Isinkaye2018). Incremental Lifetime Cancer Risk (ILCR) that presents the carcinogenic risk was calculated using equation ( 13) (Orosun et al 2020;Isinkaye2018).…”

Measurements of Seasonal Variations of Radioactivity Distributions in Riverine Soil Sediment of Ado-Odo Ota, South-West Nigeria: Probabilistic Approach Using Monte Carlo

“…While overestimation of the health risks (i.e. the absorbed dose rates and Radium equivalent activities) can lead to waste of resources on unnecessary mitigation exercise, underestimation of these risks can give rise to severe health consequences to the inhabitants (27) . Estimation of the mean values using the assessment model given by Equations 2 and 3, either overestimates or underestimates the real risk.…”

“…MCS has the advantage of letting researchers see all the possible outcomes for decisions and assess the impact of risk, giving room for better decision making under uncertainty. It executes the risk analysis through building models of probable results by exchanging array of values (probability distribution) for any factor with intrinsic uncertainty (27) . The MCS then computes the results multiple times (10 000 trials were adopted in this work), in each occasion expending different arbitrary values from the probability functions.…”