More Hygienic Health Concerns

I’ve written here a couple of times before about variants of the “hygiene hypothesis” — the idea that our environments, which are extraordinarily clean by evolutionary standards, are keeping some children’s immune systems from developing normally, because they are not exposed to the range of microorganisms that the immune system needs to “see” in order to calibrate itself.  There has also been concern that over-use of anti-microbial agents to remove bacteria from the environment may contribute to antibiotic resistance.

The New Scientist today has a short article relating concerns about another widely used compound, triclosan, which is used as an anti-bacterial and anti-fungal agent in soaps, toothpaste, deodorant, mouthwash, other cosmetic products, and household cleaning supplies. There is some evidence that its use in toothpaste may help in the prevention of gingivitis, but there is no clear health case for its widespread use.

Although there have been, in the past, some concerns expressed about the possibility that triclosan might contribute to anti-biotic resistance, more recent concern has focused on its possible role as an endocrine hormone disruptor.

Over the next year, the FDA will look at evidence that triclosan might affect the development of the nervous system, in which thyroid hormones play a key role, or the reproductive system.

Animal studies suggest that triclosan can lower the levels of thyroid hormone, and boost the effect of estrogen and testosterone.

It seems that we have, for some time now, been engaged in a large and uncontrolled experiment that will determine the effect this and many other chemical substances will have on human health.  We should not, perhaps, be entirely surprised if we do not like the answer.

Adobe Updates Reader, Acrobat

Adobe has released a new version, 9.3.2, of its popular Reader software, to address several critical security vulnerabilities.  The problems affect all prior versions of Reader for Windows, Mac OS X, and UNIX/Linux, and prior versions of Acrobat for Windows and Mac OS X.  Further information on the vulnerabilities is in the Adobe Security Bulletin APSB10-09.   The fixes can be downloaded via the automatic update mechanism (from the main menu, Help / Check for Updates).  Alternatively, users can download the new version of Reader from the following links:

• Windows (You want the 9.3.2 Update.)
• UNIX / Linux  (This is full new version.)
• Mac OS X (You want the 9.3.2 Update)

Acrobat users should see the Security Bulletin for update information.

Since Adobe Reader is very widely installed, it is a popular target for malicious software developers.  I recommend applying the updates as soon as you conveniently can.

Another Java Security Update

Oracle / Sun has released a new version of the Java run-time environment to address a serious security vulnerability that existed when Java was run from within a browser. (Details of the vulnerability are given in the Oracle Security Alert CVE-2010-0886.  Brian Krebs also has a write-up on the flaw at his “Krebs on Security” blog.)  According to Oracle, the problem only affects browsers on 32-bit systems.

You can download the updated version, Java 6 Runtime Environment Version 6 Update 20, from this page.   If you have automatic updating enabled, you should receive the fixes within a couple of week.  Further information on changes in this version is in the Release Notes.

Happy Birthday, Leonardo

Today, April 15, is “income tax day” here in the US, the day on which most income tax returns from individual tax payers are due.  (One can make too much of this — it has been possible for many years to get an automatic extension of the time allowed just by sending a short form to the IRS.)

As Wired‘s “This Day in Tech” feature reminds us, it is also the 558th anniversary of the birth of Leonardo da Vinci, born in 1452 in a hill town, Vinci, in Tuscany.  He is, of course, the artist responsible for some of the most instantly recognizable paintings in the world, including the Mona Lisa and The Last Supper.  He also really does epitomize the title “Renaissance Man”, having been, in addition to an artist, an anatomist, architect, and engineer.  Working for the Duke of Milan (Italy as a country was still a few centuries in the future), he designed fortifications and sketched ideas for  military machines, including a multiple-barrel gun, and a helicopter.

Leonardo died in France in 1519, at the age of 67.