121 Exhibit P152 is a document dated 29 March 1966 signed by Dr S F McCullagh, and entitled "Notes and Comment, Biological Effects of Asbestosis, Annals of the New York Academy of Sciences, Volume 132, pages 1 - 766, 31 December 1965". Dr McCullagh's letter head describes his practice as industrial and preventive medicine. He later became James Hardie's chief medical officer and was titled the company's Federal Medical Officer. Dr McCullagh writes that in the US the accepted safe upper limit is 5 million particles per cubic foot while the British adopt a rather lower level expressed as 4 fibres per millilitre. However, in both the US and the UK it is said that there is no safe upper limit, that all fibre and any fibre is dangerous. In the UK there is reason to believe that in some plants dust is now so well controlled that it no longer is any danger - though it would be years before it can be established that this is so. Dr McCullagh noted that it seems that once a sufficient exposure has occurred it is simply a matter of time before asbestosis develops, one is concerned with time from first exposure rather than with the duration of the exposure, but he could find no certain information as to what is a sufficient exposure. Dr McCullagh said it was fair to say that asbestos fibre is generally held to be associated with and probably the cause of two forms of cancer, bronchogenic carcinoma and mesothelioma (cancer of the pleura, or, less commonly, of the peritoneum in the abdomen). Dr McCullagh noted that it was suggested that even a brief and slight exposure may result in mesothelioma. Dr McCullagh noted that it was suggested that the increasing use of asbestos products, with their slow disintegration and the release of "indestructible" asbestos fibres, was leading to a dangerous pollution of the urban atmosphere throughout the world.