§ John Barrett
To ask the Secretary of State for Environment, Food and Rural Affairs what the average air quality levels were in England in each year between 1985 and 1995. 
§ Mr. Bradshaw
Comprehensive information on concentrations of air pollutants in England between 1985 and 1995 is available from the Air Quality Archive at www.airquality.co.uk. The following table shows, for urban and rural air monitoring site sin England, the average number of days for the years between 1985 and 1995 on which levels of any one of a basket of five pollutants (carbon monoxide, nitrogen dioxide, ozone. fine particles and sulphur dioxide) were 'moderate or higher' according to the Air Pollution Information Service bandings. These data are the headline air quality indicator, one of 15 headline indicators of sustainable development.
Data are missing for some years because there were, at that time, not enough air monitoring sites operating to provide data on all pollutants. Data for 2002 for England are available at www.sustainable-development. gov.uk/indicators/regiona1/2002/h10.htm and for 1987–2003 for the UK at http://www.defra.gov.uk./news/ 2003/030508a.htm.
When the indicator was established in 1998, the back time series was constructed from results from an increasing set of monitoring sites as the network (particularly the urban network) was developed. Research demonstrated that the increasing number of sites used in the indicator in fact had little effect on the overall trend produced. However, caution should be taken when comparing data for the early years of the urban network, as the number of sites was much lower than present that could have resulted in a lower number 521W of exceedences being detected. The number of urban sites increased from three in 1992 to 35–40 from 1998 onwards, while the number of rural sites has remained fairly constant since it started.
The table also shows average concentrations of black smoke and sulphur dioxide (SO2) in the UK between 1985 and 1995. These two combustion-generated pollutants are also a good indicator of average air quality for the years in question.
There is no clear trend in the average number of days of 'moderate' or 'higher' air pollution between 1985 and 1995. There is annual variability due mainly to differences in weather conditions from year to year. Data since 1995 show a long-term improvement in the number of days of 'moderate' or 'higher' air pollution as a result mainly of reduced emissions from road vehicles, electricity production and industry. There is an improving trend in average UK concentrations of black smoke and sulphur dioxide between 1985 and 1995, which have almost halved.
Average air quality levels between 1985–1995 England air quality
(number of days)
(Micrograms per metre
1985 — — 17.5 41.2 1986 — — 17.7 41.1 1987 23 — 17.0 39.1 1988 34 — 15.9 36.5 1989 58 — 14.7 35.3 1990 58 — 14.3 35.6 1991 60 — 13.4 32.8 1992 52 — 11.6 29.6 1993 44 59 11.0 28.2 1994 52 50 9.0 24.6 1995 53 50 10.6 24.4
§ Norman Baker
To ask the Secretary of State for Environment, Food and Rural Affairs what the total amount of recognised carcinogens released to the air was(a) in England and (b) broken down by Government region in each year since 1997. 
§ Mr. Bradshaw
The National Atmospheric Emission Inventory (available on-line http://www.naei.org.uk/) compiles annual air pollutant emissions for the United Kingdom. The most recent year for which emissions have been calculated is 2001. Emissions of four known or probable human carcinogens are calculated: benzene, 1,3-butadiene, benzo[a]pyrene and dioxins. Table 1 shows the national annual emissions since 1997 taken from the National Atmospheric Emission Inventory.
Emissions are generally calculated using statistics that are available on a national scale (e.g. fuel use). Inventory experts are gathering the regional information in order to undertake the complex process of calculating regional totals. So far, emissions for England have been calculated for 2001, but emissions for each Government region are not yet available.522W
Table 1: UK emissions 1997 to 2001 Units 1997 1998 1999 2000 2001 Benzene kt 35.8 31.7 28.7 15.7 15.4 1,3-Butadiene kt 7.3 6.4 5.9 5.1 4.5 BaP t 11.2 9.7 8.6 6.7 7.2 Dioxins gTEQ 471 411 395 346 341
Table 2: England emissions for 2001 Units 2001 Benzene kt 11.8 1,3-Butadiene kt 3.7 BaP t 6.1 Dioxins gTEQ 272
1. BaP = benzo[a]pyrene (a carcinogen in its own right and a marker for carcinogenic polycyclic aromatic hydrocarbons in ambient air;
2. The term dioxin refers to a range of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran compounds. The emissions of dioxins are presented in terms of the sum of the weighted emissions expressed as gTEQs. TEQs weight the toxicity of the less toxic congeners as fractions of the toxicity of 2,3,7,8-TCDD, the most toxic congener.