Health risk assessment and heavy metal exposures among residents in Kampar, Perak

• Main Author: Hang, Zhong Yu
• Format: Final Year Project / Dissertation / Thesis
• Published: 2023
• Subjects: TD Environmental technology. Sanitary engineering; TP Chemical technology
• Online Access: http://eprints.utar.edu.my/5806/1/fyp_EO_2023_HZY.pdf; http://eprints.utar.edu.my/5806/

In today’s modern world, people tend to spend a lot of their time indoors, which has become significant during the COVID-19 pandemic. In Malaysia, there are only a few health risk assessment studies on heavy metal exposure. There are no policies as standard reference values for heavy metals in the indoor air. Therefore, the potential health risks caused by heavy metals in the indoor environment warrant greater attention. This cross-sectional study was established aims to examine the human health risks associated with indoor dust exposure for Zn, Fe, Pb, Cu, Cr, and Mn among Kampar residents. Thirty-four (34) indoor dust samples were collected from each household in four residential areas in Kampar using handheld vacuum cleaners. Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) was used to analyse six heavy metal concentrations (Zn, Fe, Pb, Cu, Cr and Mn) in the dust samples after they had been digested with aqua-regia. The United States Environmental Protection Agency’s (US EPA) carcinogenic and non-carcinogenic model human health risk assessment tools for children and adults were adopted to estimate the potential health risk levels. The results indicated that heavy metal concentrations (ppm) in the indoor dust from the selected areas ranged from 1.317-48.042 (Zn), 0.144-4.859 (Fe), 0.010-0.070 (Pb), 0.006-1.571 (Cu), 0.006-0.115 (Cr), and 0.008-0.102 (Mn). Among the studied areas, Taman Kampar and Westlake Residential Area illustrated higher heavy metal concentrations than the other two areas. There were significant differences for the concentrations of Zn (χ 2=8.932, p=0.030), Fe (χ 2=8.707, p=0.033) and Pb (χ 2=8.885, p=0.031,) in the dust samples across the 4 different housing regions, with higher mean rank values for Taman Kampar and Westlake Residential area. The surrounding human activities, high population density, and high traffic flow were the main sources of the high heavy metal concentrations. Except for Zn-Cu (ρ=0.338, ix p=0.050,), Fe-Pb (ρ=0.287, p=0.100), and Cu-Pb (ρ=0.181, p=0.307), all metals demonstrated significant correlations ρ=0.338, p=0.050,), Fe-Pb (ρ=0.287, p=0.100), and Cu-Pb (ρ=0.181, p=0.307), all metals demonstrated significant correlations (p<0.05) at a 95% confidence level in these studies. The Mn-Zn (ρ=0.719) and Mn-Fe (ρ=0.824) correlation coefficients were determined to be highly positive. For the health risk assessment of adult and child populations, the hazard index (HI) values were less than the maximum of 1, making insignificant non-carcinogenic effects to both populations. On the other hand, the total lifetime cancer risk (TLCR) values of adults and children were not within the range of 1x10-6 – 1x10-4 , indicating no carcinogenic risk to the populations. Moreover, this study also demonstrates that children may be more vulnerable to all three exposure pathways: inhalation, ingestion, and dermal contact compared to adults. Similar to many studies, exposure via the ingestion pathway posed the highest risk for adults and children in this study. In conclusion, this study found no carcinogenic or noncarcinogenic risks from heavy metal exposure in indoor dust samples from residential houses in Kampar. However, it is recommended to regularly clean the house and maintain ventilation to maintain good indoor air quality. Significantly, this study provides baseline data for policymakers to develop guidelines and regulations for indoor air quality to protect the public health in Malaysia.