What are the toxic effects of sulfur dioxide (SO2) exposure?

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Last updated: February 27, 2025View editorial policy

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From the Guidelines

Sulfur dioxide exposure is associated with significant toxic effects, including respiratory, cardiovascular, and total mortality, with reductions in SO2 concentrations leading to decreased mortality rates, as evidenced by a study in Hong Kong where an 80% reduction in SO2 concentrations was linked to a 2.1% decrease in total mortality 1. The toxic effects of sulfur dioxide exposure are multifaceted, affecting various systems in the body. Key effects include:

  • Respiratory problems: coughing, wheezing, shortness of breath, and chest tightness due to irritation of the eyes, nose, and throat
  • Cardiovascular issues: associated with increased risk of cardiovascular mortality, as seen in the Hong Kong study where a reduction in SO2 concentrations led to a 2.0% decrease in cardiovascular mortality 1
  • Other health issues: potential for pulmonary edema, bronchospasm, and respiratory failure in severe cases Treatment for sulfur dioxide exposure involves:
  • Immediate removal from the source
  • Administration of supplemental oxygen
  • Bronchodilators like albuterol for bronchospasm
  • Corticosteroids such as prednisone for severe cases to reduce inflammation
  • Thorough irrigation with saline solution for eye exposure It is crucial to note that sulfur dioxide combines with moisture in the respiratory tract to form sulfurous acid, causing chemical burns to mucous membranes. Individuals with pre-existing respiratory conditions, such as asthma or COPD, are at a higher risk for severe reactions and may experience symptoms at lower exposure levels than healthy individuals. The study in Hong Kong highlights the importance of reducing SO2 concentrations to minimize its toxic effects, with significant reductions in mortality rates observed after the intervention 1.

From the Research

Toxic Effects of Sulfur Dioxide Exposure

The toxic effects of sulfur dioxide (SO2) exposure have been extensively studied, and the evidence suggests that SO2 can have detrimental effects on human health. Some of the toxic effects of SO2 exposure include:

  • Oxidative damage in multiple organs 2
  • Chromosomal aberrations, DNA damage, and gene mutations in mammals 2
  • Adverse effects on the respiratory, cardiovascular, and nervous systems 3
  • Increased risk of type 2 diabetes and non-accidental deaths 3
  • Bronchial hyperreactivity, which can persist for several years after exposure to high concentrations of SO2 4

Organ-Specific Effects

SO2 exposure can also have organ-specific effects, including:

  • Lung injury and myocardial injury in rats 2
  • Vascular remodeling and pulmonary hypertension 2, 5
  • Negative inotropic effect on cardiac function at high concentrations 5
  • Endothelium-dependent vasorelaxing effect at low concentrations 5

Synergistic Effects

The evidence also suggests that SO2 can have synergistic effects when combined with other air pollutants, which can exacerbate its adverse health effects 3. Overall, the toxic effects of SO2 exposure are a major concern, especially in developing countries where sulfur dioxide emissions remain high 3.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Sulfur dioxide: foe or friend for life?

Histology and histopathology, 2017

Research

Effects of sulfur dioxide inhalation on human health: a review.

Reviews on environmental health, 2024

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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