Yupo said:
A little late in having a more focused look at what you said, Yupo - I don't have answers, yet fwiw, as per what is in bold above, there are two categories of asbestos (amphibole and serpentin) fibers, such as the blue type (crocidolite) and the brown's (amosite) of which both are of the amphilole family. This family is cited as being scaled worse (for health) than lets say chrysotile fibers, and it is chrysotile that makes up much of the consumer/industrial products (including house building products) where exposures result (the older brake linings, boiler wrapping, textured ceilings etc.). These asbestos types are not always assured in products, depending on where industry sourced the asbestos, yet products are most often associated with these likley types of asbestos. There are other sub asbestos types in the two categories mentioned.
Not sure if you caught it, however, a few pages back there was a link to the study by Berry and Liddel that looked at these smoking issues, and than further it was noted that the rise in glutathione seemed to be consistent with smoking and reduced asbestos related disease of those who were exposed; I was surprised at first, yet the rise in glutathione made some sort of sense. I was surprised, too, because that is what one always hears, so I don't imagine those studies are popular in certain circles; and perhaps they are not all correct either. Nonetheless, from your work, and you see things as said, you likely well know that asbestosis and mesotheliomas are the two most discussed effects of asbestos exposure, with the latter perhaps not so empirical (alleged effects) due to it being more strongly suggestive in publications.
Anyway, so in most discussion one reads on asbestos disease, they seems to always point to smoking as a causative contributor of said diseases (and you said you could see a correlation), yet I'm starting to question that based on the presents of glutathione when smoking, and its ability in coating the lungs in a protective manner from particulates (perhaps even against silica i.e. silicosis, and other particulates too). I'm just speculating here that the studies that are in favor of asbestosis being increased with smoking being the contributor, just may have some flaws of data, as many smoking studies do, yet I've not spent enough time looking deeply at it. Nonetheless, one example could be that those that work with asbestos; workers, may in their lives have been exposed to other toxins that have either directly contributed or weakened their systems to have allowed for it. Another might be that there is generally a 20 - 30 year time delay from initial exposure of asbestos and the development of asbstosis or mesotheliomas. In North America (as a generality) house products containing asbestos stopped that production in the mid 80's. Working with people in trades going back to the pre 80's, there was a high percentage of workers that smoked then. If workers who then developed the above diseases were asked if they smoked, statistically that would be high in a statistically high population of smokers back then. On the other hand, of all those exposed who never developed said diseases and did smoke, did smoking help? Seems to me that there needs to be many questions asked; what were the exposures, over how many years and what types of asbestos - and many more questions.
One other thing to possibly consider is that asbestos fibers from natural sources (depending within what geoclimatic area and season of influence); albeit in lower fibers per cubic centimeter (f/cc), fibers are essentially in the everyday outdoor air we breathe (and of course indoors, especially if asbestos is part of the structure/products), and is continually made airborne by our winds (or indoors by our ventilation systems and disturbances). So outdoors it exists naturally in and on soil surfaces, and is made more prevalent when it drys and becomes aloft. The point being is that humans are constantly being exposed to asbestos, there is no real avoiding it, yet commercial usage or localized product exposures indeed was or in some part of the world is tremendously high.
Concerning data regarding smoking's contribution to disease, I'm often at an impasse a) because there are many benefits that are documented for some people and, b) it seems that there are so many variants in peoples lives and their day to day exposures that are not looked at or not recorded in studies. An asbestos example of this is that in more serious asbestosis cases, it is said to be accompanied with a breakdown in the immune system. Well that would be logical, however, as discussed above, there are a great deal of factors that could help compromise ones immune system, perhaps smoking is somewhere on the list for some people, yet there is much more here than smoking it would seem, and smoking is the red flag they like to use - if you ask they question and they say yes, I smoked, nothing much else is asked; its a done deal.
It's a curious thing at this point, this data relationship with disease and smoking, and hope to learn more.
:D 
