health data for Wolverhampton, UK showing how domestic smoke affects the outcomes

Smoky and less smoky Wolverhampton - the variations of health outcomes

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Introduction

map

Wolverhampton wards and area not covered by smoke control leglisation

Wolverhampton is a city of a quarter million population on the north west fringe of the West Midlands conurbation in the centre of England. It's economy used to be dominated by various metal industries but is now more mixed. It has higher than average unemployment and is relatively deprived. It is ethnically mixed including one of the highest Sikh populations in the UK and with a substantial afro-carribean population. It is divided into twenty wards used for democratic political representation on the local Council. Wards are also used for social analysis and for health outcome compilation by the national government. Clockwise, from Penn ward to Fallings Park ward, the boundary is mostly rural, the rest borders onto the urban districts of Walsall, Sandwell and Dudley. Wolverhampton has a high population density, particularly so in the areas not smoke controlled which also co-incides with higher ethnic minority populations.

1. Designating the smoky and non smoky area

Wolverhampton does not suffer obviously poor air pollution. Winter smogs are very few, localised and transient. The experience of nasal, bronchial and chest irritation due to a nearby smoky chimney is common. The problem may not be the domestic smoke pollution contribution to the general ambient air but more of heavy localised exposures in built up areas. Much of the housing stock in the non controlled areas is of Victorian teraces of individual plots of 60m2 or less. It is possible that a number of residents not only live less than ten metres from a smoky chimney (excluding their own) but also have over fifty potentially smoky chimneys less than 50m away. Contrast that result to an area of detached housing where there that number may be only half a dozen. See ref: bbc news ;

Designating the smoky part of Wolverhampton and being able to rely upon health data is not easy as:

Domestic smoke crosses ward boundaries.
Non compliance with regulations within smoke controlled zones.
Lack of smoke control does not imply a domestic smoke presence.
Population migration between wards.

Six wards are distinctly more smoky than the rest of Wolverhampton. They are : Blakenhall, Ettingshall, Graiseley, Park, St Peters and Spring Vale.

2. Population profile

Age profile is a strong determiner of health outcomes, especially that proportion over sixty years of age.

	Population 2002	0 - 59	60 - 74	75 +	(of which 85+)
Wolverhampton	236582	78.1%	14.0%	7.8%	(1.85%)
Smoky part	73735	79.7%	12.8%	7.5%	(1.90%)
Rest of Wolverhampton	162847	77.4%	14.6%	8.0%	(1.80%)
England and Wales	52478000	79.2%	13.3%	7.6%	(1.95%)

Smoky Wolverhampton has a younger age profile than the Rest but is not disimilar to the national profile. The Rest of Wolverhampton has an older profile than that nationally and should have worst health outcomes as a consequence. Refs: Wolverhampton ;

3. Deprivation

Deprivation is a general indicator of lower life expectancy and , hence, higher death rates. The government ranks the 8414 wards in order from 1 as most deprived to 8414 as most privileged.

	Average rank order
Smoky Wolverhampton	1027
Rest of Wolverhampton	1808

The six smoky wards are more deprived than the rest of Wolverhampton and should expect slightly worse health outcomes. However, the difference is not large and health outcomes are used as one of the determiners of deprivation which lessens the difference between the two when discussing health outcomes.

4. 2002 Mortality all ages

	All ages number / percentage	under 75 years number / percentage	over 75 years number / percentage
Smoky Wolverhampton	864 / 1.17%	328 / 0.481%	536 / 9.72%
Rest of Wolverhampton	1696 / 1.04%	690 / 0.460%	1006 / 7.76%
England and Wales	535300 / 1.02%	187100 / 0.386%	348200 / 8.71%

Given its younger age profile, smoky Wolverhampton has a very high death rate. The whole of Wolverhampton has a high premature death rate with the smoky part being slightly worse. The over 75 years relatively low death rate for the Rest of Wolverhampton is partially explained by its lower 85 years profile. Refs: lancet review ; comeap ;

5. Diabetes mortality 1999 - 2001

	Number	Average rate per year
Smoky Wolverhampton	38	0.017%
Rest of Wolverhampton	95	0.019%

The prevalence of diabetes is sometimes used as a lifestyle affected mortality. The evidence shows little difference between the two designated parts of Wolverhampton so certain lifestyle factors should not affect other types of mortality such as that due to heart disease. Refs: diabetes UK ; International Diabetes federation .

6. Lung cancer mortality (all ages) 1999 - 2001

	Number	Average rate per year
Smoky Wolverhampton	100	0.0452%
Rest of Wolverhampton	336	0.0688%

Air pollution is a cause of lung cancer mortality but it is small compared with tobacco smoking (ten percent of lung cancers are due to air pollution) and the mortality rates are a good but inprecise indicator of smoking patterns. Smoky Wolverhampton has a similar rate to that nationally but the Rest of Wolverhampton has a much higher rate which means it also should have a much higher rate of cardiovascular and respiratory mortality. Refs: Jama study ; possible NO2 link ; ten percent report ; indoor coal smoke ; Danish study ; China studies Pubmed ; China Study EPA ; overview pdf ;

7. Respiratory mortality (all ages J00 - J99) 1999 - 2001

	Number	Average rate per year
Smoky Wolverhampton	397	0.179%
Rest of Wolverhampton	755	0.155%

A 15.5% increase in Smoky Wolverhampton over the Rest despite a much lower prevalence of smoking. Refs: WRI Study ;

8. 2001 Respiratory mortality sub group of Bronchitis, Emphysema and COPD (all ages J40 - J44)

	Number	Average rate per year
Smoky Wolverhampton	37	0.050%
Rest of Wolverhampton	66	0.040%

Again, a greater rate in the Smoky six wards. Refs: bbc news ; UK lung deaths twice EU average study ; bbc article on COPD;

9. Circulatory system mortality (all ages) 1999 - 2001

	Number	Average rate per year
Smoky Wolverhampton	1072	0.476%
Rest of Wolverhampton	2136	0.432%

There is 10.2% more cardiovascular deaths in the Smoky part than in the Rest despite the apparent difference in smoking rates. Refs: heart disease and air pollution ; American heart association ; Celcius ; comeap ;

10. Ischaemic heart disease mortality sub group (all ages) 1999 - 2001

	Number	Average rate per year
Smoky Wolverhampton	542	0.245%
Rest of Wolverhampton	1141	0.234%

Similar rates despite the dissimilar smoking patterns. The age standardised rate nationally is about 0.2% (see HSQ 21, page 71) See also: American heart association ;

11. Ischaemic heart disease mortality under 65 years age standardised 1994 - 98

	rate per 100 000
Smoky Wolverhampton	130
Rest of Wolverhampton	102

Ward population weighting were used in the averaging. A much higher rate in the Smoky part of the city.

12. Stroke (cerebrovascular) mortality sub group (all ages) 1999 - 2001

	Number	Average rate per year
Smoky Wolverhampton	304	0.137%
Rest of Wolverhampton	556	0.114%

A much increased rate in Smoky Wolverhampton. Of the four neighbouring urban districts, only Dudley has a total ban on smoky fuel and which has a much lower hospital admission rate for the under 65's compared with the other three. See also ref: bbc news ; American heart association ; China stroke study pdf ;

13. Circulatory mortality age standardised under 75 years

	1994 -98 average rate / 100000	1995 -99 average rate / 100000
Smoky Wolverhampton	207	196
Rest of Wolverhampton	162	161

The national rate over this period is about 135 / 100000 and falling. Increased smoking rates account for the rest of Wolverhampton but not for Smoky Wolverhampton where the mortality rate due to cardiovascular disease is high.

14. All cancer mortality age standardised under 75 years

This table is for illustration only. The figures are not ward population weighted. The less smoky part of Wolverhampton is a bit above the national level probably due to higher smoking rates.

	1994 -98 average rate / 100000	1995 -99 average rate / 100000
Smoky Wolverhampton	144	137
Rest of Wolverhampton	152	145

15. Low Birthweight 1996 -99

	Total births	Number < 2500g	percentage low birthweight
Smoky Wolverhampton	4010	475	11.75
Rest of Wolverhampton	8552	818	9.57

The national average over this period is about 8%. Wolverhampton has a higher than average teenage pregancy rate which explains a general elevated level. The lowbirthweight rates are one of the worst nationally. Refs: New York 9/11 ; Czech study ; entlink review ; Ambient CO link to birthweight ; Review of CO link ; WHO study ;
Sao Paulo study ; EHP Review ;

16. Infant mortality 1986 - 99

Air pollution has been alleged to be a cause of some infant mortality. These figures must be treated with caution as the averaging did not take into account birth number variations in the wards. They are averages of rates per 1000 births in each ward. The average nationally over this period is about 8 (decreasing from 10 to 6 ref: HSQ 21). Refs: birth defects ;

	rate per 1000
Smoky Wolverhampton	10.1
Rest of Wolverhampton	8.1

17. Wolverhampton and Dublin

The capital city of Ireland introduced a city wide ban on the use of bituminous coal for domestic heating in 1990. A study carried out in 2002 studied the mortality differences due to respiratory and cardiovascular disease. The researchers studied the death rates for six years prior to the ban to the six years after.

	Dublin decrease in the annual rate after coal ban	Increase between Smoky Wolverhampton over the Rest
Respiratory mortality	15.5%	15.5%
Cardiovascular mortality	10.3%	10.2%

The figures may be a co-incidence but the similar variation between cardiovascular and respiratory mortality is indicative of strong evidence that domestic smoke is causing an increased death rate in Wolverhampton. The actual excess number is fifty but the total is probably more due to some domestic smoke related deaths occuring in the less smokier part of Wolverhampton. Dublin air pollution as measured by black smoke fell by 70%. Perhaps the smokier parts of Wolverhampton has 70% greater pollution than the cleaner parts of Wolverhampton or that average exposure is 70% greater because of high density housing which is more likely. Refs: Irish health ; vhi healthcare ; Harvard University gazette ; airmap pdf ; Harvard medicalnews ; Lancet 19-10-2002 (Main reference);

18. Discussion

Exposure to air pollution is a cause of increased cardiovascular mortality, repiratory mortality, lung cancer mortality and low birthweight babies. It may be a cause of other health outcomes. The evidence of the health outcomes presented here is consistent with the evidence of many research papers which have linked air pollution to worsened health outcomes, both in the actual outcome and size of effect. A city wide ban on the domestic use of bituminous coal in Wolverhampton would save over fifty lives each year. Bituminous coal is a lot smokier (in terms of its pm10 emission factor) than either "smokeless" (smokless fuels such as anthracite are smoky but their concentrations are sufficiently low as to be invisible) or wood fuels, but the evidence indicates that even these fuels are potentially dangerous especially in built up areas. To safeguard people's health, it would make sense to only allow fuels burnt in domestic appliances to have an emission factor no more than 0.1g/kg in high density housing areas and no more than 1g/kg elsewhere in built up areas. For low density housing and for isolated properties a more relaxed standard can be implemented. Other smoke/air pollution sources are also a problem, transport, passive cigarette smoke, cooking, industrial activity and cause ill health and they too should be tackled. A nation wide switch to the clean domestic fuels such as gas and electricity would save lives, many lives. Refs: Hong Kong ; Armidale health review ; Burning Issues Review ; China review ; World Bank indoor air review ; itdg indoor air review ; New Zealand domestic emissions standard pdf ; New Zealand domestic heating;

19. References used to compile the data on this web page:

Vital Statistics Tables VS4d 1999 National Statistics (UK Government)
Vital Statistics Tables VS4d 2000 National Statistics (UK Government)
Vital Statistics Tables VS4d 2001 National Statistics (UK Government)
Vital Statistics Tables VS4 2002 National Statistics (UK Government)
Our Children Our Future; Report of the Public Health of Wolverhampton 1999 (available from Wolverhampton Primary Care Trust)
New City New Century; Report of the Public Health of Wolverhampton 2001 (available from Wolverhampton Primary Care Trust)
Health Statistics Quarterly HSQ20 winter 2003 downloadable from www.statistics.gov.uk
Health Statistics Quarterly HSQ21 spring 2004 downloadable from www.statistics.gov.uk
Wolverhampton statistics from http://neighbourhood.statistics.gov.uk/

20. Measuring ambient air quality in Wolverhampton:

Photos and bonfire and Wolverhampton Council Air Quality site