For some time, concerns have grown that children are more vulnerable to asbestos fibres than adults. It has been suggested that, as a child’s lungs are still developing, he or she may be more vulnerable to contracting asbestos-related diseases than adults. With asbestos in schools such an emotive issue, this is clearly a sensitive question. Nigel Bryson considers the challenges ahead.
As a result of concerns raised by various individuals and organisations, the Department for Education (DfE) asked for advice from the Committee on Carcinogenicity (CoC) in 2011 about whether or not children were more vulnerable to asbestos fibres than adults. The request actually originated from an advisory group within the DfE called the Asbestos in Schools Steering Group. This group aims to promote effective management of asbestos in schools and contributes to the development of management guidance on asbestos.
In June 2013, the CoC stated: “we conclude that exposure of children to asbestos is likely to render them more vulnerable to developing mesothelioma than exposure of adults to an equivalent asbestos dose.”
So how did they come to this conclusion and what does it mean?
Balance of probabilities
The review essentially considered two issues.
The effect of age when someone may be exposed to asbestos and life expectancy.
A child’s susceptibility to injury, for example whether the lungs of a child are more susceptible to the damage caused by asbestos fibres than an adult.
The CoC undertook an assessment that included evaluating and reviewing the following.
The available epidemiology literature on childhood exposure to asbestos and risk of developing mesothelioma in later life.
Animal studies that had compared changes related to asbestos fibre exposure of juvenile animals, contrasted with exposure in later life.
The differences between adults and children in relation to lung structure, inflammation and fibre amounts in the lungs.
Potential concentrations of asbestos to which children may be exposed, particularly in schools and residential properties.
The information on low-level exposure to asbestos available from the scientific committee of the Health and Safety Executive (HSE) Advisory Committee on Toxic Substances, known as WATCH.
This review took around two years and the CoC reported its findings publicly in June 2013. In its statement, the CoC acknowledged that there were uncertainties in some of the evidence. It confirmed the carcinogenic properties of asbestos and that buildings with asbestos that had been disturbed or in a poor condition are likely to give rise to most fibres in the atmosphere.
The CoC observed that most data regarding asbestos levels in schools was historic, “and there is a lack of contemporary data on asbestos in schools”. It suggested more recent exposure data should be obtained in view of “the importance of the issue”. It also concluded that asbestos exposure could arise at home as well as at school. Elevated levels would only be likely where the materials had been disturbed.
With regard to the possibility of developing mesothelioma, the CoC concluded that there was good epidemiological evidence to suggest that “childhood exposure to asbestos can cause mesothelioma in later life”. However, this was not due to the immature physiology of children’s lungs but rather the fact that the children were exposed to asbestos for longer than those exposed in their adult years. The CoC found, for a given dose of asbestos, the following.
Considering differences in life expectancy, the lifetime risk of developing mesothelioma is predicted to be 3.5 times greater for a child first exposed to asbestos at the age of 5 compared to an adult first exposed at the age of 25.
Where a child is first exposed to asbestos at the age of 5 compared to an adult first exposed to asbestos at the age of 30, the lifetime risk of developing mesothelioma is predicted to be 5 times that of the adult.
So, in relation to life expectancy from early exposure, children are more likely to be vulnerable to developing mesothelioma compared to an adult for a given amount of asbestos fibres.
When the differences in respiratory and immune systems between children and adults were considered, the evidence was unclear. There was evidence to indicate that children’s lungs were more susceptible to injury in the first four years of life. However, the CoC could not determine whether fibre inhalation before the age of five would affect lung function or whether any effect would persist.
When the CoC considered the position overall, it could not conclude that children are fundamentally more susceptible to asbestos-related injury. However, given the nature of mesothelioma and the long latency period in developing the symptoms from initial exposure, children are more likely to be susceptible than adults when exposed to a given dose. The CoC highlighted that there were “a number of uncertainties and data gaps” in its information on which to base a conclusion.
At the Education Select Committee Hearing on Asbestos in Schools in March 2013, the Minister for Schools, David Laws, indicated that the Government would review its policy on asbestos in schools in the light of the CoC report. At the Select Committee the Minister and the HSE maintained that the current policy was to ensure that asbestos is schools was properly managed according to the legal requirements.
Certain members of the Select Committee suggested that surveys be carried out and a national register of asbestos in schools considered. This was not considered necessary and too costly. Professor Peto, an expert in asbestos epidemiology, suggested that identifying schools where asbestos was in poor condition was the priority. He argued that it is the concentration of fibres in the air that is important. He also gave some indication of the anticipated mesothelioma deaths from exposure of asbestos at school. He said: “It is reasonable to say that something of the order of 100 or 150 deaths per year from mesothelioma in women could, in the future, be due to asbestos levels in schools up to the 1960s and 1970s.”
It could be assumed that a similar number of males could die of mesothelioma due to asbestos levels in schools. As we no longer work with asbestos — blue and brown asbestos were effectively banned in the 1980s and white asbestos in 1999 — people born after 1962 were unlikely to work directly with the most potent forms. Professor Peto supported this assertion by stating that the amounts of asbestos in the lungs of people from the general population born in 1975 was tenfold less than those born around 1960. He then indicated that in 50 years’ time there may be around 10–15 mesothelioma deaths in women and a similar number in males related to exposure in schools.
The teaching unions and various other individuals and organisations have been calling on the Government to adopt a more proactive approach to identifying asbestos in schools. Some have called for a phased removal of all asbestos in schools. The report from the CoC is likely to be used by them to put pressure on the Government to modify its existing policy.
For those responsible for schools, the spotlight is going to be increasingly on how asbestos is managed. In the light of the CoC report, it may be a good time to ensure that all the control measures that should be in place are actually in place.
CC/13/S1: Committee on Carcinogenicity of Chemicals in Food, Consumer Products and the Environment: Statement on the Relative Vulnerability of Children to Asbestos Compared to Adults (June 2013).