2. Protection of human health

(a)

Sampling points directed at the protection of human health shall be sited in such a way as to provide reliable data on all of the following:

(b)

sampling points shall in general be sited in such a way as to avoid measuring micro-environments in the immediate vicinity of the sampling point, which means that a sampling point shall, where feasible, be sited in such a way that the air sampled is representative of air quality for a street segment no less than 100 m in length at locations measuring the contribution of road traffic, at least 25 m × 25 m at locations measuring the contribution from domestic heating, and at least 250 m × 250 m at locations measuring the contribution from industrial sites or other sources such as ports or airports;

(c)

where the objective is to assess air quality at air pollution hotspots, sampling points shall be installed in the areas within zones with the highest concentrations to which the population is likely to be directly or indirectly exposed for a period which is significant in relation to the averaging period of the limit values or target values; such sampling points shall be located, where relevant and to the extent possible, in areas where sensitive population and vulnerable groups are likely to be directly or indirectly exposed for a period which is significant in relation to the averaging period of the limit values or target values, including but not limited to residential areas, schools, hospitals, assisted living facilities, or office areas;

(d)

sampling points in urban background locations shall be located so that their pollution level is influenced by the integrated contribution from all relevant sources; the pollution level shall not be dominated by a single source unless such a situation is typical for a larger urban area; those sampling points shall, as a general rule, be representative for several square kilometres;

(e)

sampling points in rural background locations shall be located so that their pollution level is influenced by the integrated contribution from relevant sources but not by urban areas, major roads or industrial sites in their vicinity, i.e. closer than 5 km;

(f)

where the objective is to assess the contribution of road traffic, sampling points shall be located in such a way as to provide data on the streets where the highest concentrations occur, taking into consideration traffic volume (representing the largest traffic density in the zone), local dispersion conditions and spatial land use (for example, in street canyons);

(g)

where the objective is to assess the contribution of domestic heating, sampling points shall be installed downwind of the main sources within the relevant predominant wind direction of those sources;

(h)

where the objective is to assess the contributions of industrial sources, ports or airports, at least one sampling point shall be installed downwind of the main source within the relevant predominant wind direction in the nearest residential area; where the background concentration is not known, an additional sampling point shall be situated upwind of the main source, relative to the relevant predominant wind direction; the sampling points may be sited such that the application of BAT can be monitored;

(i)

sampling points shall, where possible, also be representative of similar locations not in the immediate vicinity of the sampling points; in the zones where the level of air pollutants is above the assessment threshold, the area which each sampling point is representative of shall be clearly defined; the whole zone shall, where possible, be covered by the different areas of representativeness defined for those sampling points; concentrations in areas in a zone that are not covered by that zone’s sampling points shall be assessed with appropriate methods;

(j)

account shall be taken of the need to locate sampling points on islands where that is necessary for the protection of human health;

(k)

sampling points measuring arsenic, cadmium, lead, mercury, nickel and polycyclic aromatic hydrocarbons shall, where possible, be co-located with sampling points for PM10.