What happens if you add a base?

Adding more hydroxide ions to the neutral complex pulls more hydrogen ions off the water molecules to give the tetrahydroxoberyllate ion:

The beryllium hydroxide dissolves because the neutral complex is converted into an ion which will be sufficiently attracted to water molecules.

Why doesn't this happen with, for example, calcium hydroxide?

Calcium hydroxide is truly ionic - and contains simple hydroxide ions, OH-. These react with hydrogen ions from an acid to form water - and so the hydroxide reacts with acids.

However, there isn't any equivalent to the neutral complex. Adding more hydroxide ions from a base has no effect because they haven't got anything to react with.

Note: This has been simplified to bring it into line with the sort of treatment you will meet for the acid-base behaviour of transition metal hydroxides. In particular, the structure of beryllium hydroxide is probably even more complicated than has been suggested above!

Purpose of the Workplace Study

Before this study began, we knew that people exposed to beryllium may develop two forms of beryllium disease, acute and chronic. These are lung diseases caused by exposure to beryllium. The acute form is a rare pneumonia-like disease that occurs shortly after very high exposures to beryllium. The chronic form may develop many years after being exposed to beryllium. Chronic beryllium disease is described in the fact sheet Steps to Protect Your Health.

Our study, however, focused on lung cancer. Some studies had previously linked lung cancer to beryllium exposure. However, this link was uncertain. Thus, we did our study to further examine this issue.

Description of the Workplace Study

We studied 9,225 workers employed at 7 beryllium processing plants between 1940 and 1969.

We based the study on work records that we got from the companies. We also obtained the death certificates of workers who had died. We counted the number of workers who died from each disease.

Then we calculated the number of deaths from each disease that we would expect to find in the workers, based on how often people die of these diseases in the U.S. population as a whole. If the number of deaths in the workers is higher than the expected number, then workplace exposures may be the cause.

What We Found