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UK Emissions of Air Pollutants 1970 to 1998
(1970 to 1996 version) (1970 to 1997 version)
- The following report constitutes the twelfth
annual report from the UK National Atmospheric Emissions Inventory (NAEI), and
is produced by the National Environmental Technology Centre.
- UK air pollutants - This report presents the latest estimates
of emissions to the atmosphere from the UK for the period 1970 to 1998 in a
UN/ECE format where appropriate. The total number of pollutant species included
in the 1998 annual inventory is 33- however this includes seven pollutant
groups (NMVOC, Particulate Matter, PCDD/F, PAH, PCB, HFC and PFC). Of these
pollutant groups size fractionation is available for particulate matter and
speciation is available for: NMVOCs, PAHs and PCBs. This speciation gives
individual emissions of the 500 most significant NMVOCs, the 16 PAHs identified
as "priority pollutants" by the USEPA and speciated PCB emissions. The
pollutants considered in this report are:
- carbon dioxide, CO2
- methane, CH4
- nitrous oxide, N2O
- hydrofluorocarbons (HFC)
- perfluorocarbons (PFC)
- sulphur hexafluoride
- PM10 , PM2.5 ,
PM1 , PM0.1
- black smoke
- carbon monoxide, CO
- benzene
- 1,3-butadiene
- nitrogen oxides, NOx
- sulphur dioxide, SO2
- hydrogen chloride, HCl
- non-methane volatile organic compounds (NMVOC) and associated
speciation
- ammonia, NH3
- polyaromatic hydrocarbons (PAH) and associated
speciation
- dioxins and furans (PCDD/F)
- polychlorinated biphenyls (PCB) and associated speciation
- pesticides
- lindane
- hexachlorobenzene
- pentachlorophenol
- arsenic, As - cadmium, Cd - chromium, Cr
- copper, Cu - lead, Pb - mercury, Hg
- nickel, Ni - selenium, Se - vanadium, V
- zinc, Zn
- CO2 Emission estimates for CO2
(as Carbon) from the UK show an overall decrease from 185 Mt in 1970 to 148 Mt
in 1998. The most significant reductions arise from the public power and
industrial combustion sectors. 1998 road transport emissions account for 21% of
the total emission and indicate a small decrease on the 1997 emission
estimates. Since 1990 total emissions have declined by 7.0%.
- CH4 - Estimates of methane emissions show a decline
from 3.78 Mt in 1970 to 2.64 Mt in 1998. The largest sources are landfills,
agriculture, natural gas distribution and coal mining. The reduced emissions
are dominated by the decline in the coal mining industry- in addition,
increased levels of methane recovery are now present on landfill sites. The
uncertainties associated with the emission estimates of methane are high.
- N2O - UK emissions of nitrous oxide were 0.181 Mt
in 1998. Emissions of nitrous oxide are dominated by agricultural emissions and
the production of nylon and nitric acid. Reductions have primarily arisen from
the production processes sector.
- HFC,PFC and SF6- Estimates of emissions of
halocarbons which contribute to global warming are discussed. The 1998 UK
emissions were 3.7 kt HFCs, 94 t PFCs and 54 t sulphur hexafluoride.
- PM The UK emissions of PM10 declined from
0.49 Mt in 1970 to 0.16 Mt in 1998. This reflects a trend away from coal use
particularly by domestic users. However, more recent increases in road
transport emissions (particularly from diesel road transport) have off-set a
more dramatic decline in PM10 emissions. Coal use and road transport
contribute 51% of UK emissions of PM10 in 1998. Other PM size
fractions are also included here. PM2.5 emissions have also fallen-
the largest source sector being road transport, accounting for 35% of the 1998
total emission.
- BS - Black smoke emissions in the UK declined from 1.07 Mt in
1970 to 0.28 Mt in 1998. This is largely due to a switch away from coal to
solid smokeless fuels and natural gas by domestic users. The reduction in
emissions from domestic sources has been partially offset by an increase in
emissions from diesel engined vehicles.
- CO - UK emissions of CO are dominated by those from road
transport (73% of UK emissions in 1998). Emissions in 1998 (4.78 Mt) represent
a 43% reduction on the 8.41 Mt emission in 1970 and a 31% decrease on the 1990
emission of 6.94 Mt. The change in emissions between 1990 and 1998 is dominated
by the reduction in emissions from the road transport sector, caused by the
increased use of catalytic converters in cars.
- Benzene Fuel combustion in the road transport sector is
the most significant source of benzene, accounting for some 62% of the 1998 UK
emission. The use of benzene in the chemical industry give rise to stack and
fugitive emissions, which sum to contribute 14% to the UK total emission.
- 1,3-Butadiene Emissions of 1,3-butadiene are dominated
by fuel combustion in the road transport sector, which account for some 88% of
the 1998 UK emission. There have been significant reductions in the emissions
from this sector due to the increase in the number of cars equipped with
catalytic convertors.
- NOx - UK emissions of NOx were 2.50 Mt
in 1970, and 2.79 Mt in 1990. However, emissions have fallen significantly to
1.75 Mt in 1998, representing a 37% reduction on the 1990 emissions estimate.
This is primarily a consequence of: abatement measures in road transport,
abatement measures in coal fired power stations and the increased use of other
fuels for power generation. Road transport and coal combustion combine to
account for 64% of UK emissions in 1998.
- SO2 - UK emissions of sulphur dioxide have fallen
from 6.51 Mt in 1970 to 1.62 Mt in 1998. This is a result of reduced emissions
from the industrial and public power sectors arising from the decreasing use of
coal, and increasing use of abatement equipment. However, coal combustion still
accounts for 72% of the 1998 UK SO2 emissions.
- HCl - UK emissions of hydrogen chloride have fallen from 0.33
Mt in 1970 to 0.09 Mt in 1998 largely as a result of declining coal use.
- NMVOC - UK emissions of NMVOC are estimated as 2.27 Mt for
1970, 2.62 Mt for 1990 and 1.96 Mt for 1998. Reductions from 1990 to 1998 arise
primarily from the road transport and industrial sectors. NMVOC emission
estimates have been significantly improved since the 1997 inventory, and more
certain speciation is available.
- NH3 - The total UK emission of ammonia for 1998 is
estimated at 0.35 Mt, comparable to the 1990 estimate of 0.37 Mt. The
agricultural sector dominates the total ammonia emissions, and the reductions
more than offset the increased emission from the road transport sector (caused
by increased use of catalytic convertors).
-
- POPs The 1998 UK emissions of persistent organic compounds may
be summarised as follows: 1745 t PAH (USEPA 16), 325 gTEQ PCDD/F (grammes of
"toxic equivalent" of dioxins & furans) and 2.75 t PCB. Emissions from all
three of these pollutant groups have greatly decreased. Emissions in 1998
equate to decreases of 74%, 70% and 61% on the 1990 emission, for PAHs, PCDD/Fs
and PCBs respectively.
- Pb - UK Emissions of lead have declined sharply following
reductions in the lead content of leaded petrol and the increasing use of
unleaded petrol. Emissions in 1998 are estimated to be 1.03 kt compared with
7.56 kt in 1970. Road transport still contributes 57% of UK emissions in 1998.
Emissions of other metals are also reported, and show a strongly declining
trend.
- The 1998 emission inventory indicates that many of the total emission
estimates for pollutants are dominated by emissions from road transport and the
use of coal see table below.
Contribution to UK 1998 emissions from road transport and coal
combustion
Pollutant |
Total Coal
Combustion |
Road
Transport |
Total
Contribution |
HCl |
99% |
0% |
99% |
1,3-butadiene |
0% |
91% |
91% |
BS |
27% |
55% |
82% |
CO |
6% |
73% |
79% |
SO2 |
72% |
1% |
73% |
benzene |
2% |
65% |
67% |
NOx |
18% |
46% |
64% |
Pb |
6% |
57% |
64% |
PM10 |
30% |
24% |
54% |
Cu |
46% |
1% |
47% |
Benzo[a]pyrene |
20% |
26% |
46% |
CO2 as
CARBON |
23% |
21% |
44% |
Cr |
42% |
1% |
42% |
Se |
34% |
0% |
34% |
PAH (USEPA
16) |
24% |
8% |
32% |
Zn |
7% |
25% |
33% |
Hg |
31% |
0% |
31% |
VOC |
1% |
27% |
28% |
Ni |
21% |
1% |
21% |
Cd |
9% |
4% |
13% |
It is therefore likely that future trends in
emissions will be substantially determined by market demand and UK
Government/devolved administration policies associated with these
areas.
- A copy of this report may be found at the NAEI web site
(/netcen/airqual/index.html) along with a facility for
local interrogation of the data and links to data on emissions in other
countries.