Exposure to heavy metals alters the surface topology of alveolar macrophages and induces respiratory dysfunction among Indian metal arc-welders

Abstract

Background: Despite the available clinico-epidemiological evidence of heavy metal-associated respiratory health hazards among metal arc-welders, experimental confirmation of such an association is lacking. Methods: In this study, we recruited 15 metal arc-welders and 10 referent workers without direct exposure. We assessed respiratory health through a questionnaire and spirometry; estimated manganese, nickel and cadmium levels in blood, urine and induced sputum; performed differential counts of sputum leucocytes and measured plasma malondialdehyde (MDA). We used atomic force and scanning electron microscopy to assess the physical property of the alveolar macrophages (AMs) obtained from induced sputum and analysed cell surface deposition of heavy metals using energy dispersion X-ray analysis (EDX). Sputum cellular DNA damage was assessed by DNA-laddering assay. Results: There was a higher body burden of manganese and nickel in the metal arc-welders than the referents. Among major spirometric indices, only the forced mid-expiratory flow rates (FEF 25-75) were reduced in the welders compared with the referents (63.4 + 14.7 vs. 89.2 + 26.7, p < 0.01); this reduction was associated with both heavy metal levels (: À41.8, 95% CI: À78.5% to À5.1%) and plasma MDA (À0.37; À0.68 to À0.06). In metal arc-welders, significant physical and morphological changes were observed in AMs through microscopic evaluation while EDX analyses demonstrated higher deposition of heavy metals on the AM cell surface than the referents. We also observed a higher degree of DNA damage in the sputum cells of the exposed workers than the referents. Conclusion: Heavy metal exposure-induced adverse respiratory effects among metal arc-welders are mediated through haematological and cytological interactions.

Effects of an additive (hydroxyapatite–bentonite–biochar) on Cd and Pb stabilization and microbial community composition in contaminated vegetable soil

“…2 High contents of Cd and Pb in crops directly or indirectly cause adverse effects on human health and may lead to consequences such as cancer, kidney dysfunction, haematological alterations, and disorders in trace mineral proles. 3,4 However, the biotoxicity of Cd and Pb is not directly linked to the total amounts in soils but is notably related to their availabilities. 1 Cd 2+ and Pb 2+ are the predominant forms of Cd and Pb that are taken up by plants.…”

Cardiovascular risks in subjects exposed to the Brumadinho dam collapse, Minas Gerais, Brazil

“…By oral intake, heavy metals reach the bloodstream after passing through the gastrointestinal tract (5). When the exposure is through the respiratory pathways, heavy metals enter the bloodstream via the contact of the tiny alveoli with minute blood vessels; to facilitate heavy metal deposits in the bloodstream (6). Within the blood circulation, heavy metals cause increased oxidative stress and lipid peroxidation at the cellular level (7).…”