TITLE:
Cancer Risk of Inhalation Exposure to Cd, Cr, As, Be and Ni in Ambient Air
AUTHORS:
Heba M. Adly, Saleh A. K. Saleh, Abdullah A. Saati, Sameer H. Fatani
KEYWORDS:
Carcinogens, Trace Elements, Particulate Matter, PM10
JOURNAL NAME:
Journal of Environmental Protection,
Vol.8 No.3,
March
23,
2017
ABSTRACT: Particulate matter may comprise toxic trace elements
with carcinogenic effects. Of these trace elements, Cadmium (Cd), Chromium
(Cr), Arsenic (As), Beryllium (Be) and Nickel (Ni) are classified as probable
human carcinogens. During the annual Hajj pilgrimage, 2.3 million pilgrims stay
in Makkah, Saudi Arabia; the increased vehicle traffic contributes to elevated
concentrations of particulate matter. We aimed to determine the excess cancer
risk (ECR) associated with inhalation
exposure in the Makkah population. This study was conducted in the
Arafat area, which is a highly-crowded area during Hajj. Inductively coupled plasma-mass spectrometry (ICP-MS) was
used for trace element analysis. ECR resulting from inhalation exposure to each
metal was calculated in accordance with the unit risk suggested by the
Integrated Risk Information System. In summer, including Hajj, mean Cd, Cr, As,
Be, and Ni atmospheric concentrations were 0.098, 0.008, 0.26, 0.03, and 0.012
μg/m3, respectively; in autumn,
values were 0.06, 0.006, 0.16, 0.002, and 0.01 μg/m3, respectively.
ECRs were 1.08 × 10, 7.21 × 10, 4.0 × 10,
4.6 × 10, and 2.4 × 10, respectively, exceeding the acceptable
inhalation risk level (1.0 × 10) set by the US Environmental
Protection Agency for each element. Higher atmospheric trace element
concentrations in summer were due to high temperatures that increased atmospheric turbulence, leading to a greater
amount of re-suspended dust from roads and blowing sand particles. These
findings can be used by relevant authorities while developing
regulations and strategies for developing air quality management to improve the health of pilgrims; however, larger
prospective studies are required to estimate ECR in different seasons.