Gaseous vs. polluting fuels for cooking, heating lower odds for COPD, wheeze

Key takeaways:

• The likelihood for several respiratory conditions/symptoms decreased with use of gaseous vs. polluting fuels for cooking and heating.
• Gas fuel use raised the odds for pneumonia and COPD vs. electricity use.

Use of gaseous household fuels vs. polluting fuels for cooking and heating lowered an individual’s odds for COPD, wheeze and severe respiratory illness/death, according to study results published in Lancet Respiratory Medicine.

“This article demonstrates a significantly lower risk for key health outcomes when switching from polluting solid fuels or kerosene to gaseous fuels for cooking or heating, suggesting cleaner fuels could contribute to reducing the global disease burden from exposure to household air pollution,” Elisa Puzzolo, MSc, MPH, PhD, senior research fellow and in the department of public health, policy and systems at University of Liverpool and co-director of the university’s CLEAN-Air (Africa) Global Health Research Unit, and colleagues wrote.

Using 10 databases, Puzzolo and colleagues reviewed and assessed 116 studies published between Dec. 16, 2020, and Feb. 6, 2021, to find out how gaseous fuels (natural gas, liquified petroleum gas and biogas) used for cooking and heating impact various health outcomes compared with polluting fuels (wood, charcoal, kerosene) or clean energy (electricity, solar energy).

A majority of the included studies followed a cross-sectional design (78 studies), with fewer cohort studies (23 studies), case-control studies (13 studies) and randomized controlled trials (2 studies).

The number of studies conducted in low-income and middle-income countries (LMICs) was similar to the number of studies conducted in high-income countries (60 studies vs. 54 studies). Two studies featured countries from both income levels.

Further, 92 studies focused on fuels used in cooking, whereas only 17 studies focused on fuels used in heating. Seven studies evaluated both fuel usage areas.

Researchers obtained 215 effect estimates from the total population.

Between gaseous household fuels and polluting fuels, use of gaseous household fuels proved to be more beneficial to an individual’s health, with reduced odds for several health effects and symptoms, including:

• pulmonary function deficit (OR = 0.27; 95% CI, 0.17-0.44);
• severe respiratory illness or death (OR = 0.27; 95% CI, 0.11-0.63);
• COPD (OR = 0.37; 95% CI, 0.23-0.6);
• self-reported breathlessness (OR = 0.4; 95% CI, 0.21-0.76);
• wheeze (OR = 0.42; 95% CI, 0.3-0.59);
• self-reported cough (OR = 0.44; 95% CI, 0.32-0.62);
• acute lower respiratory infections or pneumonia (OR = 0.54; 95% CI, 0.38-0.77);
• bronchitis (OR = 0.6; 95% CI, 0.43-0.82);
• preterm birth (OR = 0.66; 95% CI, 0.45-0.97); and
• low birth weight (OR = 0.7; 95% CI, 0.53-0.93).

Researchers also found significantly decreased odds for COPD, bronchitis, pulmonary function deficit and severe respiratory illness or death pooled together (OR = 0.36; 95% CI, 0.27-0.48) with gas fuel vs. polluting fuel.

In this analysis, the likelihood for asthma in adults and children (49 estimates) in relation to gas use was not significant, according to researchers.

In contrast, individuals who used gaseous household fuels vs. electricity faced a higher likelihood for acute lower respiratory infections or pneumonia (OR = 1.26; 95% CI, 1.03-1.53), as well as COPD (OR = 1.15; 95% CI, 1.06-1.25). Researchers noted that in higher-quality studies, determined using the Liverpool Quality Assessment Tool, the relationship between these health outcomes and gas vs. electricity usage was non-significant.

Use of gaseous household fuels vs. electricity lowered an individual’s odds for bronchitis (OR = 0.87; 0.81-0.93).

Similar to the above asthma findings, the likelihood for asthma in adults and children in relation to gas use vs. electricity was not significant. Researchers observed additional non-significance in this analysis when assessing the odds for wheeze, cough and breathlessness.

“For LMICs reliant on polluting solid fuels and kerosene, transitions to gaseous fuels for cooking or heating can potentially produce substantial health benefits,” Puzzolo and colleagues wrote. “However, where transitions to clean energy such as electricity are a realistic option (ie, scalable and accessible in the short term) further protection of health is probable.”