34 Assessment of lung function, oxidative stress, inflammation, heavy metals, and polycyclic aromatic hydrocarbon metabolites in occupational exposure to sand dust

Abstract Background/Objectives Exposure to sand dust has been associated with chronic respiratory conditions including carcinogenesis of the lungs. Heavy metals and polycyclic aromatic hydrocarbons (PAHs) in sand have been implicated in the pathologic mechanisms. This study assessed the lung function (Peak expiratory flow rate (PEFR)), heavy metals (Arsenic (As), Cadmium (Cd) and Iron (Fe)), oxidative stress indices (total plasma peroxide (TPP), total antioxidant capacity (TAC), oxidative stress (OSI) reduced glutathione (GSH), malondialdehyde (MDA), and nitric oxide (NO)), high sensitivity C-reactive protein (HsCRP), and PAH metabolites (2-hydroxy naphthalene (2-OHNAPH), 9-hydroxy fluorene (9-OHFLU), 3-hydroxy phenanthrene (3-OHPHEN), 1-hydroxy pyrene (1-OHP) and 3-hydroxy benzo{a}pyrene (3-OHBaP)) among sand workers. Methods Thirty sand workers and 30 controls (25 to 65 yr) were enrolled into this cross-sectional study. The PEFR was determined using the peak flow meter, TPP, TAC, GSH, MDA and NO) by colorimetry, HsCRP by ELISA, arsenic, cadmium, iron by AAS, PAH metabolites by GC-MS and OSI by calculation. Results The TPP, MDA, OSI, CRP, As, Cd, Fe, 2-OHNAPH, 9-OHFLU, 3-OHPHEN, 1-OHP and 3-OHBaP were higher and PEFR, TAC and GSH lower in sand workers than controls (P < 0.05). Sand workers who had worked for 1 to 5 yr had lower TAC and CRP than those who had worked for >5 yr (P < 0.05). Positive correlations were observed between 1-OH-Pyrene and 9-OHFLU (r = 0.627, P = 0.000), and 3-OH-phenanthrene (r = 0.493, P = 0.005) respectively only in sand workers. Conclusions Occupational exposure to sand dust is associated with increased heavy metals, PAHs, inflammation, lipid peroxidation and reduced antioxidants and lung function which may predispose sand workers to chronic obstructive lung conditions and cancer.