How long-term metal and lead exposure among foundry workers affect COVID-19 infection outcomes in Jordan

Abstract

Foundry workers face a number of occupational health hazards, which may lead to an increased risk of respiratory disease, cancer, and anxiety level and are associated with endocrine, hematologic, renal, and neurological problems in humans. This study aims to evaluated thyroid functions, glutathione level, and the risk of infection with SARS-CoV-2 after vaccinated (two doses of the BNT162b2 mRNA COVID-19 vaccine) foundry workers in Jordan. We examined the efficacy BNT162b2 vaccine by calculating the rate of mortality and the degree of severity from mild to severe respiratory infections in 105 adult males foundry workers occupationally exposed to metals and Pb who had been received two doses, 21 days apart, of the BNT162b2 vaccine. Seventy-five male subjects not exposed to the Pb and who received two shots of the BNT162b2 vaccine (Pfizer–BioNTech) served as the control group. In foundry workers who were infected with COVID-19, the mortality rate (0%) was similar as in the control group (0%), and increased transmission of infection with SARS-CoV-2; the non-hospitalized infections increased nearly 3.4-times and hospitalized infections increased 4.29-times among people exposed to lead and metal contamination compared to the healthy persons control group. Also, among the foundry workers, the blood lead, FT3, and FT4 levels were significantly higher (p < 0.0001) and the levels of glutathione and TSH were significantly decreased (p < 0.0001) compared with the control group. In conclusion, long-term exposure to Pb is associated with a risk of infection with COVID-19 despite the 2 doses of the BNT162b2 vaccine (Pfizer–BioNTech). Also, exposure to Pb is associated with hyperthyroidism and a reduction in glutathione.