Dear editor,

The use of biomass for domestic use is still a challenge for public health as it generates indoor contamination. Evidence indicates that rural residents with exposure to biomass are at increased risk of respiratory infections and chronic obstructive pulmonary disease (COPD)¹. Worldwide, approximately 3 billion people do not have access to clean cooking fuels². An example of this is India: 50% of households continue to use polluting solid fuels to meet their energy needs, including cooking³. In Peru, as of October 2017, 1 million 751 thousand 433 households used solid fuels for cooking (21.2% of all registered households in the country), 70.1% in rural areas⁴. The use of this fuel in our country is currently a very worrying reality.

Furthermore, the COVID-19 quarantine affected household fuel use of 700 million in Sub-Saharan Africa: 27% of households that used primarily liquefied petroleum gas (LPG) for cooking before quarantine, switched to kerosene (14%) or firewood (13%), causing a probable increase in indoor pollution⁵. This situation has not been evaluated in our country, but it is a possibility, and it would be an interesting research topic.

In places such as Mexico⁶ and India³, exposure before biomass consumption has been associated with greater susceptibility to COVID-19 infection with greater morbidity and mortality. Other studies also support the link between biomass air pollution and COVID-19^7,8.

COPD due to biomass consumption (the most frequent in our country) is characteristic of women of small stature, obese, from rural areas, and with an interstitial lung pattern⁹. Characteristically it is underdiagnosed comorbidity and not considered by patients and health personnel. This could explain why it is not being considered in a different hospital and epidemiological studies in our country.

We should mention, for example, that, in a recent study in a hospital of the Ministry of Health in Piura-Peru, it has been found that of 391 patients with Moderate / severe COVID-19, 48 (17.7%) reported previous and prolonged consumption of biomass, and 19(20%) died (Data not yet published).

As measures with potential short-term impact would be the early and sensitive screening of questionnaires or forms of diagnosis of biomass consumption in patients with COVID-19 and the long term, support for the energy and sustainable conversion of rural households to the cooks with clean fuels¹⁰.