Division 3

Information on ambient concentrations of sulphur dioxide, nitrogen dioxide, particulate matter (at least PM₁₀), ozone and carbon monoxide shall be updated on at least a daily basis, and, wherever practicable, information shall be updated on an hourly basis. Information on ambient concentrations of lead and benzene, presented as an average value for the last 12 months, shall be updated on a three-monthly basis, and on a monthly basis, wherever practicable.