The following Report was sent by Tony Allan, Castle Cement, to the Webmaster, CANK to support their contention that the new kiln is safe.
 

CANK's Response
       Analysis by Drs Howard and Staats de Yanes, Liverpool University
       CANK Letter d/d 19 January 2000 regarding Dr Roberts' Report

See also further discussion during cross examination of Dr Roberts at the Autumn 2000 Public Inquiry

CANK Note:
It emerged, subsequently,  that Dr Robert's report was based entirely on information furnished by the Environment Agency
which, in turn, had been provided only by Castle Cement.
 
 

Department of Public Health
North Wales Health Authority
Hendy Road
Mold
Flintshire
CH7 1PZ
 

1. Introduction

Castle Cement have applied for permission to build and operate a new cement kiln, kiln 4, at their Padeswood Works in Flintshire. In addition to conventional fuels, the kiln would be able to burn a variety of waste materials. These include Cemfuel (a mixture of various combustible liquid waste), tyres, plastics and paper. Concern has been expressed locally about the health effects of emissions from the kiln, and this document examines evidence on the potential effects on the health of local residents.

The aims of the document are:

• To give a general overview of the mechanism by which health is considered and safeguarded during the statutory consideration of industrial developments in general.
• To describe what is known of the health effects of the main pollutants.
• To examine evidence on the health implications of the proposed development of kiln 4 at the Padeswood Works.
• To consider whether special local health studies would be useful.
• To draw conclusions about the health impact of emissions from the proposed kiln

Even without the involvement of health professionals at a local level, health is an integral part of the assessment of the current application in at least four specific ways. Health is a consideration, directly or indirectly, in the following processes:

a)     Consideration by the Environment Agency (EA) at national level of the BPEO (Best Practicable Environmental Option)
        for the disposal of each category of combustible waste.

b)     Assessment of the environmental impact of the development by the company making an application for Integrated
        Pollution Control (IPC) authorisation. The best practical environmental option (BPEO) is assessed using technical
        guidance from the EA (Note E1 BPEO Assessments for IPC) which specifies acceptable levels for environmental
        pollutants based on guidlines recommended by national and international expert groups from The Department of Health,
        Department for Environment and the World Health Organisation (WHO).

c)    Assessment by the EA of the impact of the development on Local Air Quality Standards. These standards are based on
       the recommendations of the Expert Panel on Air Quality Standards (EPAQS) which considers the health effects of air
       pollution when setting standards.

d)    Finally, the effect on human beings is a material consideration during the Local Authority planning process.
 

3. What are the health effects of the main forms of air pollution?

The UK Committee on the Medical Effects of Air Pollutants (COMEAP) has quantified the health effects of the chemicals responsible for the majority of air pollution. Their findings are based on numerous studies of very large populations exposed over long periods to air pollution from the burning of fuel in vehicles and households, as well as in industry.

Sulphur Dioxide (SO2)
This gas is a respiratory irritant, especially in people with asthma. Significant increases in the daily average SO2 concentration cause a small rise in deaths due to heart and chest problems and, in people over the age of 65 years , increases acute admissions for chest problems. There may also be long term effects on chest problems. There does not appear to be a threshold below which SO2 has no effect on health.

Nitrogen Dioxide (NO2)
Large increases in levels of NO2 result in a small overall increase in deaths.

Particulates
Fine dust (particulates, PM2.5, PM10, etc) are more associated with health effects than coarse dust larger than 10 micrometers in diameter. The chemistry of the particles, for example sulphate particles associated with SO2, is relevant to their effect on health. Significant increases in PM10 concentrations result in a small increase in deaths and acute hospital admissions for chest problems and heart problems. There may be long term effects of exposure to particulates. There does not appear to be a level below which particulates have no effect at a population level.

Ozone (O3)
Ozone is a secondary pollutant because it is not produced directly by burning fuel but is produced by the action of sunlight on nitrogen dioxide in the presence of volatile organic compounds. Significant increases in levels of ozone result in small increases in deaths overall and acute hospital admissions for chest problems. Evidence of an association with asthma admissions is weak. There appears to be a threshold for health effects at 100ug/m3 (8 hour average).

Dioxins and Furans
Polychlorinated di-benzo dioxins and furans are by-products of certain combustion processes. We are exposed to them every day in our diet, which is the source of most of our dioxin exposure. For example the average daily dioxin exposure from diet in the UK is around 125 picogrammes (TEQ)/day, mainly from animal products. WHO has classified the most toxic dioxin - TCDD - a human carcinogen and has set a safe daily exposure level to dioxins of 1 - 4 picogrammes per kilogram body weight.

Anxiety
Anxiety about the health effects of emissions from local sources of pollution may effect the mental and physical health of certain individuals. Anxiety may be exacerbated by episodes of visible pollution or odours, an absence of information on health or misinformation about the level of risk. Therefore, minimising unauthorised releases, effective systems to respond to complaints about visible pollution or odour and the availability of factual information on levels of risk and health effects are important.
 

4. What are the likely health effects of the development of kiln 4?

Both the existing and proposed works release SO2, NO2, particulates, dioxins and other pollutants. This assessment does not take in to account the effect of unauthorised releases, the effect of increased traffic locally or the contribution of non stack emissions (from delivery and movement of materials around the site) to dust and particulate releases.

The contribution of the proposed kiln 4 to peak ground level concentrations of the main pollutants in the area is, according to modelling, small (Table 1). Average contributions will be lower than those shown in the table.

Table 1: Contribution of kiln 4 to ground level pollutants in the area around the works.

As SO2 and particulates do not have a lower threshold below which they have no health effect, it is not possible to say that emissions of these compounds will have no effect on health. However, the absolute levels that kiln 4 will contribute to peak levels of local pollution (Table 1) would be categorised by the Department of Environment as very good and for which "harmful effects are unlikely to occur even in sensitive groups". If kiln 4 goes ahead and existing kilns are "mothballed" as has been proposed, and used only occaisionally and for a limited period each year, then there will be less pollution overall due to SO2, NO2 and dust from the proposed development in comparison to the existing works.

Ozone levels are likely to be well below the threshold for health effects.

For metals and dioxins, current medical knowledge does not allow us to estimate the effects on health of any specific level of these pollutants in the environment. However, it is possible to compare predicted emissions to "safe" levels set by expert groups (see Section 1b).

Using the methodolgy developed by the Environment Agency, emissions of metals, including heavy metals, from the proposed kiln are expected to be very low and are unlikely to have any significant effect on health. The emissions of volatile organic compounds (VOCs) are also reported to be "very small".

Significant concern has been expressed about the emission of dioxins, therefore this issue has been explored in four different ways. First, by examining theoretical maximum exposure to emissions from similar works at Ketton. Second, by comparing the findings of research on the health impact of emissions from municipal waste incinerators to planned emissions from the proposed kiln. Third, by looking at historical monitoring data from around the site. Finally, by comparing the existing emissions from conventional fuels with predicted future emissions from Cemfuel and tyres.

First, calculations of "worst case" dioxin exposure of residents living near the Ketton works were examined. This calculated the dioxin uptake for a hypothetical individual who breathed only air containing the maximum ground level concentration of dioxin and ate only produce coming from land subjected to the maximum ground level concentration of dioxin. Those calculations showed that the hypothetical individual would take in 131 picogrammes/day of dioxins, compared to the average intake in the UK of 125 picogrammes/day. In reality, no residents would ever be exposed to this extent, but the method shows that the maximum theoretical exposure could not exceed 5% of the normal daily intake of dioxins.

Second, research on the extent of exposure to dioxin and furan emissions and the risk to human health experienced by populations living near Municipal Waste Incinerators was studied. The study, carried out for the Department of the Environment in 1996, considered all the possible routes of exposure such as inhalation, food and ingestion of soil (eg on vegetables) to all possible ages, infants to adults, including farmers. In all the possible scenarios they examined, the total of the "normal" background dose added to the dose from the incinerator emissions of polychlorinated dibenzo-p-dioxins (PCDDs) and polycholrinated dibenzofurans (PCDFs) were well below the safe daily exposure levels set by the WHO. When the findings of that research are applied to individuals living near the proposed kiln, it suggests that the kiln will, on average, add less than 0.1% to the "normal" background intake of dioxins and furans in local people.

Third, local monitoring data is available on dioxin and furan levels in the soil from the perimeter of the works and other locations 1km and 2km away, near the centre of Penyffordd, Rhos-y-Brwynmer, and Meadowslea Hospital. Examination of this data suggests that the existing works have not resulted in significantly increased levels of these pollutants in the local environment.

Finally, the results of monitoring similar kilns at Ketton and Clitheroe shows that dioxin emissions from those kilns are very low, and dioxin emission did not increase when Cemfuel and tyres were added to coal, compared with burning only coal. Assuming similar waste materials will be burned at Padeswood works, the concentration of dioxins in emissions from the proposed kiln is not expected to increase compared to the existing works. Therefore, the planned emissions of dioxins and furans from the proposed kiln are negligible alongside the normal daily intake of these chemicals and will have no significant health effects.

The Committee on the Medical Effects of Air Pollutants (COMEAP) reported in November 1998 on health impact of Cemfuel in the Clitheroe area of Lancashire. They found that the concentrations of substances detected in air samples taken around the works, including particulates and dust, did not indicate any concern for health. They also noted that data on respiratory diseases collected by the East Lancashire Health Authority did not show any adverse effects among residents living in Clitheroe when compared to people living elsewhere in the health authority.
 

5. Would special local health studies be useful?

The effects of even very large increases in levels of air pollution on small populations are not measurable because of the small number of cases that would result.

For example, if the current local background levels of pollution from sulphur dioxide doubled (an increase of 100%) this would increase deaths and hospital admissions by 1% for as long as the levels were increased. In a population of 10,000 people this is equivalent to around one extra admission to hospital for every year of increased pollution and around one additional death for every ten years of increased pollution. These effects would not be measurable against the normal background of deaths and admissions. The predicted contribution of the proposed kiln to the current peak (not average) background levels of pollution is actually around 5% (Table 1).

Therefore special local health studies will not be useful. However, the normal surveillance of the health of the local population by general practitioners, hospital consultants and public health authorities will continue.
 

6. Conclusion

Individuals living in the area of the works are very unlikely to suffer any harmful effects from authorised emissions of any pollutant, including dioxins, from the proposed kiln.

Dr R.J. Roberts, Consultant in Public Health Medicine, November 1999

Acknowledgement
I gratefully acknowledge the help of a number of individuals and organisations in drawing together the documents which formed the basis of this assessment.