Having high levels of certain chemical contaminants in the blood is associated with an increased risk of SARS-CoV-2 infection and of developing COVID-19.
This has been determined in a study carried out by researchers from the Hospital del Mar Medical Research Institute in Barcelona (IMIM), the Barcelona Institute for Global Health (ISGlobal, a center promoted by the “la Caixa” Foundation), the University of Las Palmas, and the Network Biomedical Research Centers CIBERESP (Epidemiology and Public Health), CIBEROBN (Obesity and Nutrition) and CIBERINFEC (Infectious Diseases), in Spain.
This is the first prospective study in the world that analyzes data obtained before the pandemic on the blood levels of pollutants in healthy people.
The results of this work provide a possible new explanation for the fact that there are large differences in susceptibility to SARS-CoV-2 infection and to COVID-19. Why, under similar exposure conditions to the virus, do some people become infected and others not? Why do some develop the disease and others not? Today, these observations and questions remain largely without sufficient scientific explanation. “What the study observes is that some of these contaminants increase the risk of being HIV-positive and of having the disease,” says Miquel Porta, one of the main authors of the study, a researcher at the Hospital del Mar Medical Research Institute and head of the group. of CIBERESP. Other factors that influence these differences between people are the diseases that a person already suffered from (the more comorbidity, the more risk of COVID-19), smoking, age, educational level, the density of people in a home or exposure to the virus on public transport or at work.
The researchers had frozen blood samples from 154 healthy people from the general population of Barcelona obtained in 2016. They have linked the levels of contaminants in these people with the frequency of SARS-CoV-2 infection and the incidence of COVID-19 during 2020-2021 in the same people. And they have observed that in cases with higher blood levels of some contaminants, the risk of infection and developing the disease was greater. In relation to the risk of COVID-19, those responsible are DDD and DDE, derived from the insecticide DDT, as well as lead, thallium, ruthenium, tantalum, benzo(b)fluoranthene and manganese. The risk of infection was greater the higher the blood levels of thallium, ruthenium, lead and gold, while it was lower the higher the concentrations of iron and selenium. “An also very relevant finding of the study is that it identifies mixtures of up to five substances from various chemical groups that increase the risks mentioned”, adds Gemma Moncunill, a researcher at ISGlobal and CIBERINFEC; and co-author of the study.
From left to right: Miquel Porta, Laura Campi, José Pumarega and Magda Gasull, from the research team. (Photo: IMIM / CIBER)
The study authors believe these results have considerable scientific and societal relevance, offering the first prospective, healthy general population-based evidence of a possible link between personal concentrations of some pollutants and COVID-19.
These contaminants reach our body through multiple routes, such as electronic devices and their use in feed in intensive farming. For this reason, if it is confirmed that the associations found are causal, measures will have to be applied in those areas to control the corresponding risks.
The study is entitled “Individual blood concentrations of persistent organic pollutants and chemical elements, and COVID-19: a prospective cohort study in Barcelona”. And it is published in the academic journal Environmental Research. (Source: IMIM / CIBER)