Pollution Characteristics and Health Risk Assessment of Airborne Heavy Metals Collected from Beijing Bus Stations

Abstract

Airborne dust, which contains high levels of toxic metals, is recognized as one of the most harmful environment component. The purpose of this study was to evaluate heavy metals pollution in dustfall from bus stations in Beijing, and to perform a risk assessment analysis for adult passengers. The concentrations of Cd, Co, Cr, Cu, Mo, Ni, Pb, V and Zn were determined by inductively coupled plasma mass spectroscopy (ICP-MS). The spatial distribution, pollution level and potential health risk of heavy metals were analyzed by Geographic Information System (GIS) mapping technology, geo-accumulation index and health risk assessment model, respectively. The results indicate that dust samples have elevated metal concentrations, especially for Cd, Cu, Pb and Zn. The nine metals can be divided into two categories in terms of spatial distribution and pollution level. Cd, Cr, Cu, Mo, Pb and Zn reach contaminated level and have similar spatial patterns with hotspots distributed within the Fifth Ring Road. While the hot spot areas of Co and V are always out of the Fifth Ring Road. Health risk assessment shows that both carcinogenic and non-carcinogenic risks of selected metals were within the safe range.

Heavy Metal Pollution and Human Health Risk Assessment of Farmlands around Enyigba Lead-Zinc Mining Site, Ebonyi State, Nigeria

“…Thus, there is no guarantee of cancer risks safety at the sites in future if all the routes is taken into cognizance and as such, resident farmers may still be under threat of cancer if appropriate precautionary measures are not in place. Implications of similar results have been reported [3,9,10]. 47523 1.31983 0.03532 0.10450 0.38173 1.05072 0.70230 1. Soiling 0.00770 0.03370 0.00040 0.00160 0.00140 0.00610 Soilderm-abs 0.00008 0.00035 0.00001 0.00006 0.00008 0.00033 Soilinh 0.00006 0.00028 0.00000 0.00001 0.00001 0.00005 T. occidentalis 0.00304 0.00839 0.02190 0.06000 0.00770 0.02120 A. hybridus 0.00333 0.00916 0.02400 0.06600 0.00843 0.02317 Total HRI 0.01421 0.05187 0.04632 0.12768 0.01762 0.05085 C Soiling 0.00370 0.01600 0.00010 0.00060 0.00020 0.00080 Soilderm-abs 0.00004 0.00016 0.00001 0.00002 0.00001 0.00005 Soilinh 0.00003 0.00013 0.00000 0.00001 0.00000 0.00001 T. occidentalis 0.00086 0.00237 0.01340 0.03680 0.00191 0.00527 A. hybridus 0.00091 0.00250 0.01530 0.04210 0.00204 0.00560 Total HRI 0.00463 0.02117 0.02881 0.07953 0.00417 0.01172 Values are mean of three (n=3) replicates ± standard deviation A = Ishiagu-Enyigba, B = Elinwobvu-Enyigba, C = Ekawoke (control) site…”

“…Non-carcinogenic health quotients for Pb and Cd were greater than the safe level (> 1) (4) for children and total noncarcinogenic health risk for the metals were greater than the safe level (> 1) [4] for both adult and children in the studied sites (Table 7). This calls for concern as resident farmers within this mining vicinity are likely under threat of multiple heavy metal toxicity [2,3,9,10].…”

“…Non-carcinogenic risk = CDI/RfD (6) Carcinogenic risk = CDI x SF (7) Where CDI is the chronic daily intake dose (mg/kg/day) of heavy metals via different routes as evaluated, RfD is the oral reference dose (mg/kg/day) of heavy metals and SF is the carcinogenic slope factor (kg.day/mg). The value of the exposure parameters (RfD and SF) via various routes [2,7,9] is shown in Table 3. 1.00 X 10 -3 1.00 X 10 -5 1.00 X 10 -3 6.10 Cr 3.00 X 10 -3 6.00 X 10 -5 2.86 X 10 -5 41.00 Ni 2.00 X 10 -2 5.40 X 10 -3 2.06 X 10 -2 0.84 Cu 4.00 X 10 -2 1.2 X 10 -2 4.02 X 10 -2 Pb 3.5 X 10 -3 5.25 X 10 -4 3.52 X 10 -3 Fe 7.00 X 10 -1 7.38 X 10 -1 7.00 X 10 -1 Zn 3.00 X 10 -1 6.00 X 10 -2 3.00 X 10 -1…”

Sequential Extraction of Some Heavy Metals in Southwest Giza Soil, Egypt

“…Index of geoaccumulation (I geo ) [17], was applied to assess the degree of soil pollution with heavy metals in this study. This method is used because it is a useful tool for the prediction of soil pollution and had been used by many authors as Sarkar et al [1], Zheng et al [18] and Milicevic et al [19].…”

Peer Review #2 of "Mercuric pollution of surface water, superficial sediments, Nile tilapia (Oreochromis nilotica Linnaeus 1758 [Cichlidae]) and yams (Dioscorea alata) in auriferous areas of Namukombe stream, Syanyonja, Busia, Uganda (v0.1)"

“…To assess the level of contamination as well as the environmental and health risks that originate from a heavy metal's occurrence, indices are used to indicate the enrichment of a given environmental component as compared to its natural concentration. The indices used to describe heavy metal enrichment of sediments include contamination factor, enrichment factor, pollution load index, geoaccumulation index, potential ecological risk and hazard quotient [53][54][55]. These indices are used as a rule at thumb to subtly assess sediment contamination.…”