Lead Pollution and Human Exposure: Forewarned is Forearmed, and the Question Now Becomes How to Respond to the Threat!

Health risk assessment of heavy metals in exposed workers of municipal waste recycling facility in Iran

Exposure to heavy metals (HMs) present in the particulate matter from municipal solid waste during pretreatment and recycling processes may pose a serious health risk to workers. This was the first study on the exposure of municipal solid waste (MSW) recycling workers to toxic metals. The concentrations of HMs (Cd, Pb, As, Co, Cr, Ni, Cu, Fe, Mn, and Zn) during personal exposure to PM2.5 among municipal waste recycling facility workers in Kashan City, Iran, were investigated from January 15 to March 15, 2023. The research was performed in the three main stages of the waste recycling process: dismantling, sorting, and collecting. PM2.5 samples were collected using a personal environmental monitor (PEM) attached to a sampling pump. The non-carcinogenic and carcinogenic health risk values and related uncertainty for waste recyclers from HMs inhalational exposure were calculated using USEPA methodology and Monte Carlo simulations. The results showed that the dismantlers exhibited the highest exposure concentrations of PM2.5 (mean 2148 ± 1257 μg m-3), followed by sorters (mean 1864 ± 965 μg m-3), and collectors (mean 1782 ± 876 μg m-3). Health risk assessment indicated that 95th percentile contents of Ni, As, Co, and Zn were responsible for the non-carcinogenic risk (HQ) values exceeding the acceptable level of 1. The contents of As, Ni, and Cr in PM2.5 caused a non-acceptable carcinogenic risk for waste recyclers due to inhalational exposure, as the carcinogenic risk (CR) values exceeded the acceptable threshold of 1 × 10-6. Monte Carlo simulation results revealed that the mean and median CR values from inhalational exposure to carcinogenic HMs exceeded the acceptable level of 1 × 10-6 for municipal waste recyclers. As results of this study indicated the high-risk to hazardous metals for waste recyclers due to occupational exposure in the MSW recycling sites, it is suggested to consider workers' exposure as the public health concern.

Distribution and health risk assessment of trace elements in ground/surface water of Kot Addu, Punjab, Pakistan: a multivariate analysis

Water is a key component for living beings to sustain life and for socio-economic development. Anthropogenic activities contribute significantly to ground/surface water contamination particularly with trace elements. The present study was designed to evaluate distribution and health risk assessment of trace elements in ground/surface water of the previously unexplored area, Tehsil Kot Addu, Southern-Punjab, Pakistan. Ground/surface water samples (n = 120) were collected from rural and urban areas of Kot Addu. The samples were analyzed for physicochemical characteristics: total dissolved solids (TDS), pH, and EC (electrical conductivity), cations, anions, and trace elements particularly arsenic (As), lead (Pb), cadmium (Cd), and zinc (Zn). All of the water characteristics were evaluated based on the water quality standards set by World Health Organization (WHO). Results revealed the suitability of water for drinking purpose with respect to physicochemical attributes. However, the alarming levels of trace elements especially As, Cd, and Pb make it unfit for drinking purpose. Noticeably, 23, 96, and 98% of water samples showed As, Cd, and Pb concentrations higher than the permissible limits. Overall, the estimated carcinogenic and non-carcinogenic risk to the exposed community was higher than the safety level of USEPA, suggesting the probability of cancer and other diseases through long-term exposure via ingestion routes. Therefore, this study demonstrated an urgent need for water filtration/purification techniques, and some quality control measures are warranted to protect the health of the exposed community in Tehsil Kot Addu.