Definitions
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 Scottish Ministers consider 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 by regulation 3(1);
“lower assessment threshold” has the meaning given by 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;
“PM2.5” 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); and
“zone” means a part of the territory of Scotland which is designated by Scottish Ministers for the purposes of these Regulations and shown on a map published by the Scottish Executive, Department of Environment, Transport and the Regions, the National Assembly of Wales and Department of Environment Northern Ireland on 19 January 2001, a copy of which is deposited at the offices of the Scottish Executive, Victoria Quay, Edinburgh, EH6 6QQ and displayed on the Scottish Executive website at http://www.scotland.gov.uk/environment/ airquality/publications.asp
(2) In these Regulations, unless the context otherwise requires, any reference to–
(a)a numbered Regulation or Schedule is a reference to the Regulation in, or Schedule to, these Regulations bearing that number; and
(b)a numbered paragraph is a reference to the paragraph in that Regulation or Schedule bearing that number in the Regulation in which the reference appears.