WHO updates global air quality guidelines
The World Health Organisation (WHO) has updated its Global Air Quality Guidelines (AQGs) to identify the levels of air quality necessary to protect public health worldwide. The guidelines focus on so-called ‘classical pollutants’ - particulate matter (PM₂.₅ and PM₁₀), ozone (O₃), nitrogen dioxide (NO₂), sulfur dioxide (SO₂) and carbon monoxide (CO) - and has lowered the limits for these pollutants based on the increasing evidence of the impact of particular pollutants on health.