Immunological effects of occupational exposure to lead (Review)

Mol Med Rep. 2017 May;15(5):3355-3360. doi: 10.3892/mmr.2017.6381. Epub 2017 Mar 24.

Abstract

It is well-known that occupational and environmental exposure to several factors, including benzene, heavy metals, chemicals and mineral fibers, is associated with the risk of developing a great number of diseases. Numerous studies have been carried out in order to investigate the mechanisms of toxicity of these substances, with particular regard to the possible toxic effects on the immune system. However, little is known about the influence of heavy metals, such as lead, on the immune system in human populations. Lead is a heavy metal still used in many industrial activities. Human exposure to lead can induce various biological effects depending upon the level and duration of exposure, such as toxic effects on haematological, cardiovascular, nervous and reproductive systems. Several studies demonstrated that exposure to lead is associated to toxic effects also on the immune system, thus increasing the incidence of allergy, infectious disease, autoimmunity or cancer. However, the effects of lead exposure on the human immune system are not conclusive, mostly in occupationally exposed subjects; nevertheless some immunotoxic abnormalities induced by lead have been suggested. In particular, in vivo, in vitro and ex vivo lead is able to improve T helper 2 (Th2) cell development affecting Th1 cell proliferation. Further studies are required to better understand the mechanisms of lead immunotoxicity and the ability of lead to affect preferentially one type of immune response.

Publication types

  • Review

MeSH terms

  • Cytokines / metabolism
  • Environmental Pollutants / toxicity*
  • Humans
  • Immune System / drug effects*
  • Occupational Exposure*
  • Reactive Oxygen Species / metabolism
  • T-Lymphocytes, Regulatory / drug effects
  • T-Lymphocytes, Regulatory / immunology
  • T-Lymphocytes, Regulatory / metabolism
  • Th1 Cells / drug effects
  • Th1 Cells / immunology
  • Th1 Cells / metabolism
  • Th17 Cells / drug effects
  • Th17 Cells / immunology
  • Th17 Cells / metabolism
  • Th2 Cells / drug effects
  • Th2 Cells / immunology
  • Th2 Cells / metabolism

Substances

  • Cytokines
  • Environmental Pollutants
  • Reactive Oxygen Species