REC: Reduction of SO2 and Particulate Emissions: Legal Framework (4.4)

4. Legal Framework (continued)

4.4. Ambient Air Quality Standards

	Some of the standards adopted by the SILAQ countries have already been mentioned in relation to the health impacts (see Section 2.2). These standards are part of a more general system of standards for SO₂ and particulate emissions adopted by the SILAQ countries which refer to air and fuel quality, and emissions from various sources. The basic components of this system are further discussed below in terms of the existing norms in the SILAQ countries, along with comparison with those standards adopted in other countries and harmonization with EU standards.
Health-related Standards	The primary standards (related to health effects) for all pollutants are for short-term (less than 1 hour), medium-term (24-hour average) and long-term (annual averages). To protect populations from any adverse health effects originating from acute exposure to air pollution, short-term standards are introduced, while long-term standards are adopted to protect the population from chronic exposure to air pollution.
Secondary Standards	The secondary standards (those related to ecological effects) augment the primary regulations for all pollutants with only the exception of CO. They serve to protect public welfare, including vegetation, materials and visibility. For example, emissions of SO₂ can result in damage to the foliage of trees and crops, and is an integral component of acid rain, which results in the acidification of lakes and streams, accelerated corrosion of buildings and monuments, and reduced visibility. The primary and secondary standards are the same for most of the criteria pollutants. Air quality standards for the SILAQ countries, the EU and the USA are given in Table 5. Additional information about the WHO (World Health Organization) Air Quality Guidelines for Europe is provided in Box 6.

Some of the standards adopted by the SILAQ countries have already been mentioned in relation to the health impacts (see Section 2.2). These standards are part of a more general system of standards for SO₂ and particulate emissions adopted by the SILAQ countries which refer to air and fuel quality, and emissions from various sources. The basic components of this system are further discussed below in terms of the existing norms in the SILAQ countries, along with comparison with those standards adopted in other countries and harmonization with EU standards.

Health-related Standards

The primary standards (related to health effects) for all pollutants are for short-term (less than 1 hour), medium-term (24-hour average) and long-term (annual averages). To protect populations from any adverse health effects originating from acute exposure to air pollution, short-term standards are introduced, while long-term standards are adopted to protect the population from chronic exposure to air pollution.

Secondary Standards

The secondary standards (those related to ecological effects) augment the primary regulations for all pollutants with only the exception of CO. They serve to protect public welfare, including vegetation, materials and visibility. For example, emissions of SO₂ can result in damage to the foliage of trees and crops, and is an integral component of acid rain, which results in the acidification of lakes and streams, accelerated corrosion of buildings and monuments, and reduced visibility. The primary and secondary standards are the same for most of the criteria pollutants.

Air quality standards for the SILAQ countries, the EU and the USA are given in Table 5. Additional information about the WHO (World Health Organization) Air Quality Guidelines for Europe is provided in Box 6.

TABLE 5: Ambient Air Quality Standards [µg/m³]

Item Bulgaria Czech Rep./Slovakia¹ Poland Romania Slovenia EU² USA³

SO₂ (with regard to health effects)

  a) Short term 500 500 600 750 - - -

  b) Medium term 150 150 200 250 - 250 365

  c) Long term 50 60 32 60 - 80 806

SO₂ (with regard to ecological effects) Not yet adopted Permitted concentrations for special protection areas n/a

  a) Short-term 500 - 250 - 350 - -

  b) Medium-term 150 - 75 - 125 - 507

  c) Long-term 50 - 11 - 50 - -

Particulate Total Suspended Particulate (TSP) (with regard to health effects)

  a) Short-term 500 500 - 500 300 - -

  b) Medium-term 250 150 - 150 175 - -

  c) Long-term 150 50 - 75 70 - -

Particulate PM10 (with regard to health effects)

  a) Short-term - - - n/a 200 - -

  b) Medium-term - - 120 n/a 125 - 150

  c) Long-term - - 50 n/a 50 - 50

Particulates (with regard to ecological effects) Permitted concentrations for special protection areas

  a) Short-term 500 - - n/a 0.350 - -

  b) Medium-term 250 - 60 n/a 0.125 - -

  c) Long-term 150 - 40 n/a 50 - 50

Combined SO₂ and Particulates (with regard to health effects)

  a) Short-term - - - n/a - - -

  b) Medium-term - 250 - n/a - - -

  c) Long-term - - - n/a - - -

1. Standards in the Czech and Slovak Republics are identical.
2 Directive 80/779/EEC
3 National Ambient Air Quality Standards of US EPA

TABLE 5: Ambient Air Quality Standards [µg/m³]
Item	Bulgaria	Czech Rep./Slovakia¹	Poland	Romania	Slovenia	EU²	USA³

SO₂ (with regard to health effects)
a) Short term	500	500	600	750	-	-	-
b) Medium term	150	150	200	250	-	250	365
c) Long term	50	60	32	60	-	80	806

SO₂ (with regard to ecological effects)	Not yet adopted	Permitted concentrations for special protection areas	n/a
a) Short-term	500	-	250	-	350	-	-
b) Medium-term	150	-	75	-	125	-	507
c) Long-term	50	-	11	-	50	-	-

Particulate Total Suspended Particulate (TSP) (with regard to health effects)
a) Short-term	500	500	-	500	300	-	-
b) Medium-term	250	150	-	150	175	-	-
c) Long-term	150	50	-	75	70	-	-

Particulate PM10 (with regard to health effects)
a) Short-term	-	-	-	n/a	200	-	-
b) Medium-term	-	-	120	n/a	125	-	150
c) Long-term	-	-	50	n/a	50	-	50

Particulates (with regard to ecological effects)	Permitted concentrations for special protection areas
a) Short-term	500	-	-	n/a	0.350	-	-
b) Medium-term	250	-	60	n/a	0.125	-	-
c) Long-term	150	-	40	n/a	50	-	50

Combined SO₂ and Particulates (with regard to health effects)
a) Short-term	-	-	-	n/a	-	-	-
b) Medium-term	-	250	-	n/a	-	-	-
c) Long-term	-	-	-	n/a	-	-	-
1. Standards in the Czech and Slovak Republics are identical. 2 Directive 80/779/EEC 3 National Ambient Air Quality Standards of US EPA

BOX 6: WHO Air Quality Guidelines for Europe

WHO Air Quality Guidelines for Europe aim to protect public health. Ecologically based guidelines for the prevention of adverse effects to terrestrial vegetation and values for protection of vegetation from nitrogen, sulfur oxides and ozone have also been established.
In general, the guidelines address single pollutants, whereas in real-life, exposure to mixtures of chemicals occur, with additive, synergal or antagonistic effects. The guidelines are only tentative, although emissions should be reduced to the lowest achievable level.
Bearing in mind the new scientific data and advances in the field of air pollution toxicology and epidemiology, the Bilthoven Division of the WHO European Center for Environment and Health (in close cooperation with the International Program of Chemical Safety and the European Commission - DG XI) undertook a process of amending, updating and extending the Guidelines. In that respect, further studies on the effect of SO₂ on vegetation were developed in cooperation with the Working Group on Effects of the Convention of Transboundary Air Pollution of the UN ECE. Critical levels for various vegetation categories were established, for ozone, SO₂, nitrous oxides and ammonia. For SO₂, critical loads representing quantitative estimates of deposition were derived.
In 1994, the health risks of exposure to CO, O₃, NO₂, SO₂ and PM10 were evaluated. The effect of these pollutants were considered both individually and in combination. Thresholds for CO, NO2, SO₂ and O3 were established, while for PM10 dose-response information was provided, giving guidance to risk managers about the major health impacts for short and long term exposure to various levels of the pollutant.
The Final Consultation on the update and revision of the WHO Air Quality Guidelines for Europe took place on October 28-31, 1996. The aim of this Consultation was to critically evaluate the recommendations of the various working groups with a view to new emerging information, consistency and transparency in the derivation of the guidelines. The Consultation approved nearly all recommended guidelines and several amendments. The adopted values concerning SO₂ and particulate matter in the WHO Air Quality Guidelines for Europe are as follows:

SO₂ 0.5 mg/m³ for 10 minutes
0.125 mg/m³ for 24 hours
0.05 mg/m³ for 1 year

SO₂ ecotoxic effects

critical level 0.01-0.03 mg/m³ depending on the type of vegetation

critical load 0.25-1.5 eq/ha/yr depending on the type of soil and ecosystem

Particulate Matter Based on exposure-response relationship

As shown in Table 5, ambient air quality standards for SO₂ and particulates have been adopted by all SILAQ countries. When related to health effects, the standards in Bulgaria are found to be the most stringent, but as already seen (Tables 1 and 2), are often violated. Romania applies weaker standards for short and medium-term exposure. With regard to standards concerning the ecological effects, the values in Slovenia are the most stringent in the short and medium-term. While the annual air quality standards are equal for Bulgaria and Slovenia, such standards have yet to be adopted in Slovakia. Regulations concerning critical sulfur levels for forests, natural vegetation and agricultural crops are currently being prepared, as well as an annual critical load for the country of 1-2 g S/m².
With regard to total suspended particulates (TSP) and their effects on health, standards adopted by the Czech Republic and Slovakia are the same as those for SO₂ emissions. For Romania and Bulgaria, greater concentrations are permitted. Slovenia has adopted the strictest short-term standards. Values for the particulate PM 10 are even more stringent, with a separate air quality standard related to health effects. As for the air quality standards related to the ecological effects of particulate matter, the values in Slovenia mirror the values for SO₂, while those in Bulgaria mirror the standards related to the health effects of the TSP.

EU Values In general, the adopted EU standard values are looser than those in the SILAQ countries, but they account for the combined effect of SO₂ and particulates. This is the reason two values appear for SO₂ depending on the concentration of the particulate matter. The synergetic effect of SO₂ and particulate matter on human health is only taken into account by the Czech and Slovak Republics among the SILAQ countries.
The US EPA has established National Ambient Air Quality Standards (NAAQS) for six pollutants (CO, Pb, NO₂, O₃, PM10, SO₂) for the protection of health and welfare. The values for SO₂ and PM10 air quality standards have been effective since 1995 (The National Air Quality and Emission Trends Report, 1995).
For particulates, the annual arithmetic mean standard is attained when the concentration is less than or equal to 0.05 mg/m³, while the 24-hour standard is attained when the expected number of days per year with concentrations >0.15 mg/m³ is <1. The 24-hour and 3-hour standards for SO₂ are not to be exceeded more than once a year.
In Japan, for example, an extensive regulation scheme exists for SO₂. This consists of an environmental quality standard that refers to a desirable environmental quality that maintains human health and nature (1974); a so-called K-value Regulation which prescribes permissible SO₂ emission limits with regard to the height of stacks (1968); a Total Mass Emission Control for SO₂ that details permissible amounts of total SO₂ emissions; and a Regulation on the Sulfur Content of Fuel set in 1971 and upgraded in 1976 to a S content within the range of 0.5-1.2 percent.
Most of the SILAQ countries revised their air emission standards during 1991 and 1995 and these standards were harmonized with international values. In Bulgaria in 1994, for example, emission standards were harmonized with International Standards Organization (ISO) and those of the World Health Organization.

	As shown in Table 5, ambient air quality standards for SO₂ and particulates have been adopted by all SILAQ countries. When related to health effects, the standards in Bulgaria are found to be the most stringent, but as already seen (Tables 1 and 2), are often violated. Romania applies weaker standards for short and medium-term exposure. With regard to standards concerning the ecological effects, the values in Slovenia are the most stringent in the short and medium-term. While the annual air quality standards are equal for Bulgaria and Slovenia, such standards have yet to be adopted in Slovakia. Regulations concerning critical sulfur levels for forests, natural vegetation and agricultural crops are currently being prepared, as well as an annual critical load for the country of 1-2 g S/m². With regard to total suspended particulates (TSP) and their effects on health, standards adopted by the Czech Republic and Slovakia are the same as those for SO₂ emissions. For Romania and Bulgaria, greater concentrations are permitted. Slovenia has adopted the strictest short-term standards. Values for the particulate PM 10 are even more stringent, with a separate air quality standard related to health effects. As for the air quality standards related to the ecological effects of particulate matter, the values in Slovenia mirror the values for SO₂, while those in Bulgaria mirror the standards related to the health effects of the TSP.
EU Values	In general, the adopted EU standard values are looser than those in the SILAQ countries, but they account for the combined effect of SO₂ and particulates. This is the reason two values appear for SO₂ depending on the concentration of the particulate matter. The synergetic effect of SO₂ and particulate matter on human health is only taken into account by the Czech and Slovak Republics among the SILAQ countries. The US EPA has established National Ambient Air Quality Standards (NAAQS) for six pollutants (CO, Pb, NO₂, O₃, PM10, SO₂) for the protection of health and welfare. The values for SO₂ and PM10 air quality standards have been effective since 1995 (The National Air Quality and Emission Trends Report, 1995). For particulates, the annual arithmetic mean standard is attained when the concentration is less than or equal to 0.05 mg/m³, while the 24-hour standard is attained when the expected number of days per year with concentrations >0.15 mg/m³ is <1. The 24-hour and 3-hour standards for SO₂ are not to be exceeded more than once a year. In Japan, for example, an extensive regulation scheme exists for SO₂. This consists of an environmental quality standard that refers to a desirable environmental quality that maintains human health and nature (1974); a so-called K-value Regulation which prescribes permissible SO₂ emission limits with regard to the height of stacks (1968); a Total Mass Emission Control for SO₂ that details permissible amounts of total SO₂ emissions; and a Regulation on the Sulfur Content of Fuel set in 1971 and upgraded in 1976 to a S content within the range of 0.5-1.2 percent. Most of the SILAQ countries revised their air emission standards during 1991 and 1995 and these standards were harmonized with international values. In Bulgaria in 1994, for example, emission standards were harmonized with International Standards Organization (ISO) and those of the World Health Organization.

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