Had a few? Most likely you are not aware that there could be ASBESTOS in beer.
Asbestos beer filters
Filtration of beer is quite a new development, considering the 6,000 year old history of brewing. The first beer filters from the 1880s was made of paper leaves, but the next generation of beer filters, was designed to house pulp cakes which where prepared from cotton fibers mixed with asbestos. [source]
Those filters were sheet filters made of a mixture containing asbestos, in order to entrap micro-organisms. [source]
Naturally, microscopic asbestos fibers will escape from the filters into the filtered fluid, thus resulting in a beer free from micro-organisms but instead full of asbestos fibers.
Are you at risk?
Since the carcinogeric properties of asbestos were regognized, in western nations asbestos was replaced in beer sheet filters with kieselguhr or perlite, allthough in the US it is known that breweries kept on using asbestos in beer filters at least until 1980. [source]
However, asbestos filters is still used for beer brewing in nations where asbestos is not yet banned, as an extension of traditional brewery since many years.
Proceed with caution
Today, when the ongoing trend of trying new brews is apparent, every mans thirst can result in drinking beer imported from nations where asbestos is still legal to use. Thus those beers might have been filtered through the traditional asbestos pulp cake filter.
Most western health authorities are not required to demand laboratory analysis to check for asbestos content in beer or other consumables, so most of those brews will be imported without checks for asbestos content.
Surely, you never thought of this when drinking beer during your lovely vacation in Thailand, or when ordering your asian beer flavour locally at the bar.
Asbestos is extremely cancerous, so is it really safe to drink fluids containing asbestos? While the known danger is when inhaling asbestos fibers, is it really safe to eat or drink items that contain asbestos fibers?