It’s a question that is often asked – can just a one-time exposure to asbestos eventually lead to the development of an asbestos-related disease? The answer is not so straightforward, and tragically, it can appear to be all too true. Just one brief period of a long forgotten exposure can cause so much unexpected devastation to a victim and their family in their retirement years.

In one recent case, a former ex-merchant seaman argues that it was his exposure to the deadly brown ‘amosite’ asbestos for just 6 hours in the late 1970s that caused his mesothelioma, the incurable cancer of the lung linings, nearly 40 years later.

Historically, the majority of mesothelioma cancer or asbestosis disease victims were men employed in British shipbuilding, heavy engineering, construction, electrical, plumbing and heating maintenance. During the peak years of use during the 1960s and 70’s, it was mostly those who regularly and frequently handled fibre insulation products and breathed in the airborne fibre dust over one or more extended periods of time during the course of their working lives who most often became victims.

Men aged under 30 more likely to be at an increased risk

During this period, the relative lack of health and safety culture in the workplace meant most men had simply no asbestos awareness to the long term health risks. Many companies also neglected to provide any kind of breathing equipment, protective clothing or warnings about the health dangers of working directly with the fibre insulation.

Medical research has also found that it was men aged under 30 when they were first exposed who were more likely to be at an increased risk of developing an asbestos-related condition later in life. In most cases, the first asbestosis symptoms of breathlessness, coughing and tight chests would only appear between 15 and 50 or more years later, and may not be immediately linked with a possible asbestos exposure decades earlier.

The former merchant seaman, however, can clearly recall the events of 1978/79, which he claims to be the one and only time he ever came into contact with asbestos.

Asbestos up to 12 inches thick was removed by hand

The seaman was employed between the late 1970s and early 80s as a deck officer by a multinational oil company on North Sea oil trade routes. One night a fault occurred to the vessel’s high pressure turbine housed in an enclosed engine room without ventilation. Before the turbine could be looked at, a number of crew members were required to remove the asbestos insulation from pipes and turbine casings, which took around 6 hours. Although it was not part of his usual duties, the deck officer was included in the emergency repair.

The insulation, which was up to 12 inches thick, was removed by hand with cutting tools, hammers and chisels, and removed in bags. Despite working without any protective breathing equipment, assurances were made that the insulation was safe to handle because it was not “blue” asbestos.

However, supporting medical evidence strongly concluded that the insulation was likely to be “brown” asbestos. Consequently, exposure over the 6 hours was likely to have increased the risk of developing mesothelioma. Both brown amosite and blue crocidolite asbestos were later banned in the mid 1980s, as they were identified as the most dangerous of the commonly used insulation materials because of their long, sharp needle fibres, which could easily and more permanently be embedded into the soft pleural tissue linings.

Risk of developing mesothelioma after an initial exposure never reduces

One recent study, which included 862 mesothelioma cases from more than 22,000 individual exposures across Europe, and as far afield as Australia, suggest that the risk of developing mesothelioma after an initial exposure never reduces, regardless of life expectancy.

The research revealed that nearly 45 per cent of pleural (lung lining) mesothelioma cases, and more than 50 per cent of peritoneal (stomach) mesothelioma cases, were diagnosed at least 40 years after a first exposure. Even after 50 years, there were still over 13 per cent of pleural cases and 23 per cent of peritoneal cases recorded. It was also found that the rate and risk of pleural mesothelioma actually intensified for 45 years following a first exposure.

Medical research has also found that some individuals have inherited genes with a potentially greater risk of mesothelioma cancer developing.

Each year around 13,000 deaths from occupational lung disease and cancer are estimated to have been caused by past exposure, primarily to chemicals and dusts at work, which includes mesothelioma fatalities.