Why in news?
A Stanford-led study reported that lighting gas or propane stoves can elevate indoor benzene concentrations above those found in second-hand tobacco smoke. The research found that benzene emitted during cooking drifts throughout homes and lingers for hours, raising concerns about indoor air quality.
Background
Benzene (C6H6) is a colourless, sweet-smelling liquid hydrocarbon. It is widely used in industry as a solvent and as a precursor for plastics, resins, synthetic fibres and detergents. Benzene naturally occurs in crude oil and is present in vehicle exhaust, tobacco smoke and industrial emissions. The International Agency for Research on Cancer (IARC) classifies benzene as a Group 1 human carcinogen. According to the UK Health Security Agency, the primary route of exposure is inhalation. Acute exposure to high concentrations can cause drowsiness, dizziness and unconsciousness. Chronic exposure is linked to bone-marrow suppression, aplastic anaemia and leukaemia.
Key points
- Study findings: The researchers found that gas and propane burners emitted 10-50 times more benzene than electric stoves, while induction cooktops emitted no detectable benzene. Concentrations measured in bedrooms and adjacent rooms sometimes exceeded international health benchmarks.
- Ventilation limits: Even when range hoods were used, indoor benzene levels remained elevated because exhaust fans were not always effective at eliminating the gas. The team noted that benzene produced from the fuel itself, rather than food, accounted for nearly all emissions.
- Health effects: Long-term exposure to low doses of benzene increases the risk of blood disorders and cancers, particularly acute myeloid leukaemia. There is no safe threshold for carcinogenic effects; any exposure carries some risk.
- Risk reduction: Replacing gas stoves with electric or induction cooktops can substantially reduce indoor benzene exposure. Good ventilation helps but may not fully eliminate risk. Policy measures could include stricter emission standards for appliances and public awareness campaigns.
Conclusion
Benzene is a pervasive pollutant with serious health implications. The study underscores the need to evaluate indoor sources of benzene and to promote cleaner cooking technologies and effective ventilation.
Sources: Indian Express; UK Health Security Agency.