US property and casualty insurers can expect asbestos liability losses to reach $US100 billion ($133.8 billion), AM Best says.

The ratings agency has raised its forecast by about 18% or $US15 billion ($20.1 billion) to reflect evolving litigation, new secondary exposure cases and longer life expectancy, resulting in more lung cancer cases being linked to asbestos.

“With no way of knowing where the end is, and given that total funding for the industries’ asbestos losses has now reached nearly $US85 billion ($113.7 billion), it is clear the asbestos issue will continue for years to come,” it says.

The property and casualty insurance industry is incurring about $US2.1 billion ($2.8 billion) in losses per year, while paying out nearly $US2.5 billion ($3.3 billion).

AM Best says longer life spans mean more people live to suffer the effects of exposure compared with four decades ago, when people died earlier of unrelated health problems.

The average age of a person diagnosed with the asbestos-linked cancer mesothelioma is 74. Average US life expectancy has risen to 78.8 from 71.4 in 1973.

“The outcome of all legislative and medical changes in more recent years has likely contributed to a higher level of claims activity,” AM Best says.

The US no longer produces asbestos, but it is still found in products such as car brake pads and clutches, vinyl tiles and roofing materials.

AM Best has maintained its environmental loss estimate at $US42 billion ($56 billion), despite more stringent clean-up standards for polluted sites and the potential for larger settlements when revisited sites are found to be more toxic than first thought.

“With the majority of ‘mega’ losses long since settled, it appears the industry has funded most of the environmental liabilities,” it says.