Paragraph 3 I1

England and Wales

(1)

An annual mean is a mean which is calculated on a yearly basis, yielding one annual mean per calendar year. The annual mean for a substance at a particular location for a particular calendar year is:

(a)

in the case of lead, the mean of the daily levels for that year;

(b)

in the case of nitrogen dioxide, the mean of the hourly means for that year; F1...

(c)

in the case of PM₁₀, the mean of the 24 hour means for that yearF2; and

(d)

in the case of benzene, either the mean of the daily levels for that year or the mean of the hourly means for that year.

(2)

For the purpose of the calculation of the annual mean for lead, the daily level for lead at a particular location for a particular day is the level at which lead is recorded as being present in the air at that location during the week in which the day occurs on the basis of a continuous sample of air taken throughout that week (each day in that week therefore being attributed with the same daily level).

(3)

“PM₁₀” means particulate matter which passes through a size-selective inlet with a 50% efficiency cut-off at 10μm aerodynamic diameter.

F3(4)

For the purpose of any calculation of the annual mean for benzene on the basis of the mean of the daily levels, the daily level for benzene at a particular location for a particular day is the level at which benzene is recorded as being present in the air at that location during the fortnight in which the day occurs on the basis of a continuous sample of air taken throughout that fortnight (each day in the fortnight therefore being attributed with the same daily level).

Annotations

Textual amendments

F1: Word in Sch. Pt. 2 para. 3(1)(b) omitted (31.12.2002) by virtue of The Air Quality (Amendment) (Wales) Regulations 2002 (S.I. 2002/3182), regs. 1(1), 2(3)(b)(i)
F2: Sch. Pt. 2 para. 3(1)(d) and word inserted (31.12.2002) by The Air Quality (Amendment) (Wales) Regulations 2002 (S.I. 2002/3182), regs. 1(1), 2(3)(b)(ii)
F3: Sch. Pt. 2 para. 3(4) substituted (31.12.2002) by The Air Quality (Amendment) (Wales) Regulations 2002 (S.I. 2002/3182), regs. 1(1), 2(3)(b)(iii)

Commencement

I1: Sch. Pt. 2 para. 3 in force at 1.8.2000, see reg. 1(1)