4: Environmental Processes

Contacts

Preface

Contents

List of Tables
List of Figures

Abbreviations

Main Body

1: Boundaries and Populations
2: Inequalities and Deprivation
3: Ethnicity and Health
4: Environmental Hazards
5: Health related behaviour
    of young people
6: Accidents
7: Cancer
8: Teeth and fluoridation
9: Coronary Heart Disease
10: Communicable diseases

Appendices

4.1    Industrial Processes

There are more than 11 million known chemicals with around 70,000 in regular commercial use (United Nations Environment Programme, 1992) and around 600 new chemicals entering the marketplace each month (Lillbridge SR, 1997). Most of these chemicals have little or no toxicological assessment and may be released into the environment during commercial production, storage, transport, use or disposal. This release may be sudden and violent such as an explosion or following a fire (NHS Executive, 1998) or more long term due to some undetected process failure (Harrad, 1999). Health Authorities are required by Health Service Guidance to identify in advance local sites which represent sources of major chemical hazard (NHS Management Executive, 1993a), to conduct surveillance of possible causative disease factors and to consider the role of point sources of pollution or contamination (NHS Management Executive, 1993b).

The University of Birmingham manages an active surveillance system for chemical incidents which was reported in last year's Key Health Data Report (Cummins et al. 1998) As well as details of acute incidents, it is also important to be aware of the location and type of chemical plant. Intelligence about these sites can be used to ensure that there is adequate expertise available to Health Authorities to deal with releases and also to be prepared for the type of contamination which may occur. This information also enables potentially vulnerable populations to be identified and appropriate surveillance and emergency response plans to be developed.

There are a number of routine data sources available to identify industrial processes. Those installations that represent a potential for catastrophic accidents are regulated under the Control of Major Accident Hazard Regulation 1999 (COMAH) and industrial processes with significant potential to affect environmental media (part 1A processes) are regulated under the Environmental Protection Act 1990 (EPA) by the Environment Agency. These major sites are relatively few in number, around 200 Part 1A and 25 COMAH and were reported in last year's Key Health Data Report. However, experience in this region has been that most chemical releases actually occur in 'lower level' processes. Local authorities regulate smaller businesses under the EPA (part 1B processes). While these may be ostensibly lower risk than COMAH or Part 1A, they are more numerous (over 2000 in the region) and use a wide range of hazardous chemicals. They include trades such as iron and steel processes, incineration, cement and lime manufacture and di-isocyanate processes (see table 4.1). Figure 4.1 shows their distribution throughout the region in 1998. Health Authorities should be liaising with local authorities regarding any potential hazards caused by particular processes or concentrations of processes.

Table 4.1 Regulation of Industrial Processes

It should also be noted that there are many processes that are not authorised under either health and safety or environmental health legislation. Subsequent Key Health Data reports will cover some of these such as closed landfill sites.

Figure 4.1 Location of part 1B industrial processes by West Midlands local authority

4.2    Drinking Water Quality (Lead)

The basic unit of water supply is the Water Supply Zone (WSZ) which is designated by the Water Company normally by reference to a source of water and which contains fewer than 50,000 people. WSZs change regularly and the University of Birmingham maintains up-to-date WSZ maps for the region. The 1998 Key Health Data Report highlighted those areas that exceeded the statutory standards for lead, polycyclic aromatic hydrocarbons and pesticides (Cummins et al 1998). This year we have concentrated on lead as the EU standard is being upgraded. Lead is a cumulative general poison with particularly serious effects for the foetus, infants, children up to six years old and pregnant women (World Health Organisation, 1996).Lead interferes with haem synthesis, calcium metabolism and can induce neurological, behavioural and cognitive effects. Lead is also associated with adverse effects on renal function, blood pressure and reproductive function (World Health Organisation, 1996).

The most important source of lead in tap water is dissolution from household plumbing systems where the pipes, solder, fittings or service connections contain lead (World Health Organisation, 1996). PVC pipes also contain lead compounds that can be leached from them. The amount of lead dissolved in drinking water is dependent on several factors including pH, temperature, water hardness and duration of contact with pipework. Soft acidic water such as that supplied from Elan Valley is the most plumbosolvent. While older properties with long runs of lead pipework are most at risk of elevated lead levels, soldered connections in new homes with copper piping can also release enough lead to cause intoxication in children (World Health Organisation, 1996). While the plumbosolvency of the water can be reduced by treatment prior to mains distribution (e.g. by phosphate dosing) and levels reduced by running the tap water for some time, the only real long term remedy is the removal of the lead pipework.

As a result of increasing concerns about the effect of even relatively low levels of lead, the drinking water standard is being tightened to a maximum of 25 µg/L by the year 2003 and to 10 µg/L by 2013. There were 69 WSZs out of around 250 in the region in 1998 that exceeded the proposed standard for lead serving a population of almost 1.6m. Figure 4.2 shows those WSZs where the proposed standard is currently breached. While it may be possible to achieve the 25 µg/L standard by source treatment, the 10 µg/L level will be a tremendous challenge. While there are still uncertainties about the exact nature of the standard (will it be absolute or based on percentile compliance for example) and the method of sampling, it is unlikely that this standard could be met without major replacement of lead service pipework. The responsibility for this largely rests with the householder who is liable for the lead service pipework from the mains connection to, and throughout, the property. The water company is only responsible for the connection from the mains to the service pipe which is generally a very short length. Given the potential expense to individual householders, Health Authorities should be engaging with water companies and housing providers regarding the strategy for meeting the forthcoming statutory levels.

Fig 4.2 Map of Water Supply Zones exceeding the proposed EU standard for lead (10 µg/L) 1998

REFERENCES

Cummins, C., Kirk, A., Saunders, P., Stevens, A. and Wilson, R. (1998) Key health data for the West Midlands 1998. DPHE 3, University of Birmingham: Department of Public Health and Epidemiology.

Harrad, S. (1999) Polychlorinated biphenyls (PCBs) in indoor air. Chemical Hazard Management 1, 3

Lillbridge SR (1997) Industrial Diasters. In: Noji EK, (Ed.) The Public Health Consequences of Diasters, pp. 354-372. Oxford University Press

NHS Executive (1998) Planning for Major Incidents The NHS Guidance pp.4-5. London: NHS Executive.

NHS Management Executive (1993a) Health Service Guidelines HSG (93)38 Arrangements to deal with health aspects of chemical contamination incidents. Department of Health ,Health Aspects of the Environment and Food Division.

NHS Management Executive (19993b) Health Service Guidelines HSG(93)56 Public health:responsiblities of the NHS and the roles of others. Department of Health ,Health Aspects of the Environment and Food Division.

United Nations Environment Programme (1992) Chemical Pollution: A Global Overview. Geneva: The International Register of Potentially Toxic Chemicals and the Global Environment Monitoring System's Monitoring and Assessment Research Centre.

World Health Organisation (1996) Guidelines for drinking water quality, Second Edition Geneva: World health Organisation.

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