Indoor Air Pollution and Lung Cancer Risk-A Systematic Review and Meta-Analysis.

Area of Science:

• Environmental Health
• Epidemiology
• Pulmonology

Background:

• Indoor air pollution is a growing concern for lung cancer development.
• Existing evidence is fragmented across different household exposure types.
• Understanding these links is crucial for public health interventions.

Purpose of the Study:

• To systematically review and consolidate epidemiological findings on indoor air pollutants and lung cancer risk.
• To evaluate associations across diverse household exposure categories and global settings.
• To provide pooled estimates of risk where possible.

Main Methods:

• Systematic literature search of major databases (PubMed, Web of Science, Scopus, Cochrane) from 2015-2025.
• Inclusion of observational studies assessing indoor exposure and primary lung cancer.
• Extraction of adjusted effect estimates and meta-analysis using random effects models.

Main Results:

• Thirty-eight studies (475,565 participants) were included.
• Significant associations found for environmental tobacco smoke (ETS), cooking oil fumes, and solid fuel/biomass combustion.
• Pooled ORs ranged from 1.83 for cooking oil fumes to 2.26 for solid fuel/biomass combustion.

Conclusions:

• Indoor air pollution from various household sources is consistently linked to increased lung cancer risk.
• Effect sizes and precision varied, necessitating cautious interpretation.
• Further prospective research with standardized exposure assessment is recommended to strengthen evidence.