The Air Quality Limit Values Regulations (Northern Ireland) 2002

Definitions and interpretation

2.—(1) In these Regulations—

“agglomeration” means a zone with a population concentration in excess of 250,000 inhabitants or, where the population concentration is 250,000 inhabitants or less, a population density per km² for which the Department considers that the need for ambient air to be assessed or managed is justified;

“alert threshold” has the meaning given by regulation 8(2);

“ambient air” means outdoor air in the troposphere, excluding work places;

“assessment” means any method used to measure, calculate, predict or estimate the level of a relevant pollutant in the ambient air;

“fixed measurements” means measurements taken at fixed sites either continuously or by random sampling, the number of measurements being sufficiently large to enable the levels observed to be determined;

“level” means the concentration of a relevant pollutant in ambient air;

“limit value” has the meaning given in regulation 3(1);

“lower assessment threshold” has the meaning given in regulation 5(5);

“margin of tolerance” means the percentage of the limit value by which this value may be exceeded subject to the conditions laid down in Schedule 1;

“natural events” means volcanic eruptions, seismic activities, geothermal activities, wild-land fires, high-wind events or the atmospheric resuspension or transport of natural particles from dry regions;

“oxides of nitrogen” means the sum of nitric oxide and nitrogen dioxide added as parts per billion and expressed as nitrogen dioxide in microgrammes per cubic metre;

“PM_2.5” means particulate matter which passes through a size-selective inlet with a 50% efficiency cut-off at 2.5 μm aerodynamic diameter;

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

“relevant pollutants” means sulphur dioxide, nitrogen dioxide and oxides of nitrogen, particulate matter and lead;

“upper assessment threshold” has the meaning given in regulation 5(5);

“the Department” means the Department of the Environment;

“zone” means a part of the territory of Northern Ireland which is designated by the Department for the purposes of these regulations and shown on a map published by the Department, the Scottish Executive, the National Assembly for Wales and the Department of Environment, Transport and the Regions in January 2001, a copy of which is deposited at the offices of the Department, Calvert House, 23 Castle Place, Belfast BT1 1FY.

(2) The Interpretation Act (Northern Ireland) 1954(1) shall apply to these regulations as it applies to a Measure of the Northern Ireland Assembly.

(1)

1954 c. 33 (N.I.)