The rationale for selection of each guideline value is supported by a synthesis of information emerging from research on the health effects of each pollutant.
In 2014, WHO issued the first-ever health-based guidelines on clean fuels and technologies for household cooking, heating and lighting.
These guidelines aim to help public health policy-makers, as well as specialists working on energy and resource issues, understand and implement best approaches to reducing household air pollution.
Two sound level monitors recorded concurrently for 24 hours at the ICU central stations and adjacent to patients.
Sample values to determine levels generated by equipment and external noise were also recorded in an empty ICU side room.
Another recommendation addresses the need for policies that prioritize substantial health benefits during the transition from use of solid, polluting fuels to clean fuels and technologies, especially in low-income and rural households.
These guidelines make recommendations for reducing health risks from exposure to ambient emissions of gases and chemicals that may infiltrate and collect indoors, as well as from chemicals that may be used in building materials or furnishings that contribute to indoor air pollution.
The document also summarizes the available information on the conditions that determine the presence of mould and measures to control their growth indoors.
The review concludes that the most important health effects are increased prevalence of respiratory symptoms, allergies and asthma as well as perturbation of the immunological system.
WHO sets recommended limits for health-harmful concentrations of key air pollutants both outdoors and inside buildings and homes, based on global synthesis of scientific evidence.
WHO guidelines cover annual and daily concentrations of fine particulates, nitrogen dioxide, sulfur dioxide, carbon monoxide and ozone (WHO, 2005).
WHO guidelines for protecting public health are formulated on the basis of the review.