Evolution of human health risk based on EPA modeling for adults and children and pollution level of potentially toxic metals in Rafsanjan road dust: a case study in a semi-arid region, Iran

Abstract

Humans can be directly exposed to potentially toxic metals in the urban environment via inhalation, ingestion, or dermal contact of dust particles. This paper focuses on human health risk assessment of urban dust contaminated with potentially toxic metals. The levels, sources, and human health risks of nine potentially toxic metals (i.e., As, Cd, Cu, Cr, Ni, Pb, Co, Mn, and Zn) in 200 road dust samples from Rafsanjan area were investigated. Pollution level was assessed using the pollution index (PI) and geoaccumulation index (I), and the health risk assessment was performed following the methodology described by the US Environmental Protection Agency. The mean concentrations of As, Cu, Pb, Cd, Cr, Ni, Zn, Co, and Mn in road dust were 105.3 ± 5.7, 791.4 ± 29.8, 123.1 ± 9.7, 28.4 ± 3.3, 3.1 ± 0.6, 18.4 ± 1.6, 252.6 ± 8.3, 16.5 ± 1.4, and 525.9 ± 21.0 mg kg, respectively. Thus, the concentrations of potentially toxic metals in road dust were higher than their corresponding natural background values, indicating that all studied potentially toxic metals were impacted by anthropogenic activities. The results of the current study are comparable to other studies conducted on road dust in other cities worldwide. Both of I and PI decreased following order Cu > Mn > Pb > As > Zn > Cd > Ni > Cr > Co. Health risk assessment indicated that both of children and adults could be exposed to a potential increased risk of developing cancer over a lifetime from exposure to arsenic through ingestion of the dust samples. However, Pb ingestion can increase cancer risk in children.

Tendencias metodológicas en la evaluación del grado de contaminación y de riesgos por metales pesados presentes en sedimentos viales urbanos

“…Los resultados mostraron que los métodos utilizados para evaluar la contaminación por MP en sistemas hídricos mediante un análisis sedimentológico y de suelos se adaptaron para el SV, lo cual permitió evaluar el riesgo de contaminación por MP en ambientes viales [28], [47], [48]. Los hallazgos también mostraron la importancia del uso conjunto de métodos de evaluación.…”

Influence of Biocorona Formation on the Transformation and Dissolution of Cobalt Nanoparticles under Physiological Conditions

“…Nanoparticle tracking analysis (Nanosight NS300, Malvern, Sweden) measurements confirmed that no detectable Co NPs were left in solution after ultracentrifugation. After the centrifugation step, 3.7 mL of the top volume of the (10,30,60, and 100 μg/L) were prepared in 1% ultrapure HNO 3 together with a blank sample (1% ultrapure HNO 3 ). Mg(NO 3 ) 2 was used as a matrix modifier during the analysis.…”

“…As a consequence, wear particles of W and Co, some of nanometer size, have been observed in road dust. 7−10 Workers in hard metal industries have further experienced negative health effects from airborne Co, 11 and WC-Co particles have shown higher reactivity and generation of free radicals (indicative of a higher toxic potency) compared with WC particles and also release of Co ions. 12−15…”

“…Nanosized particles need special attention as they, in many cases, pose a greater risk than larger sized particles on human health and the environment. , Tires with studs made of tungsten carbide cobalt (WC-Co) are frequently used during the winter season in the Northern countries. As a consequence, wear particles of W and Co, some of nanometer size, have been observed in road dust. − Workers in hard metal industries have further experienced negative health effects from airborne Co, and WC-Co particles have shown higher reactivity and generation of free radicals (indicative of a higher toxic potency) compared with WC particles and also release of Co ions. − …”

Health risk of heavy metals in street dust

“…They may accumulate in the fatty tissues in the body and affect the central nervous and circulatory systems, disrupt the normal functioning of our internal organs, act as cofactors in other diseases and may cause DNA damage (6). At present, As, Cd, Cr (VI) and Ni have been identified as carcinogenic metals to humans, while Pb is classified as probably carcinogenic to humans (9,10).…”