Information on concentrations
23.—(1) The National Assembly must, in accordance with paragraphs (2) and (3), make available information in respect of—
(a)concentrations of Group A pollutants;
(b)concentrations of Group B pollutants;
(c)concentrations of ozone; and
(d)insofar as assessed under Part 3 of these Regulations—
(i)concentrations of mercury, PM2·5 and polycyclic aromatic hydrocarbons, and
(ii)deposition rates of Group B pollutants, mercury and polycyclic aromatic hydrocarbons.
(2) The information required to be made available by paragraph (1)(a) and, insofar as it relates to PM2·5, paragraph (1)(d)(i), must be updated as respects—
(a)benzene, as an average value over the last 12 months—
(i)at least on a three-monthly basis, and
(ii)where practicable, on a monthly basis;
(b)carbon monoxide, as a maximum running average over eight hours—
(i)at least on a daily basis, and
(ii)where practicable, on an hourly basis;
(c)lead, on a three-monthly basis; and
(d)nitrogen dioxide, sulphur dioxide, PM2·5 and PM10—
(i)at least on a daily basis, and
(ii)in the case of hourly values for nitrogen dioxide and sulphur dioxide, where practicable, on an hourly basis.
(3) The information required to be made available by paragraph (1)(c) must be updated—
(a)at least on a daily basis; and
(b)where appropriate and practicable, on an hourly basis.