In The Trenches
how people perceived the safety of that
service, but the anthrax mailings had
many ordinary people afraid to open
their mail. (I knew some. You probably
did, as well.) Why the difference?
Without being political, the basic
reason is that the anthrax letters were
publicized to a huge extent. They
were very political and initially
appeared to be related to the events
of 9-11. People generally reacted
emotionally — rather than intellectually
— to the danger. The result was that
their risk assessments were flawed.
For many people, the risk appeared
much greater than it really was. What's
more, this is not at all uncommon.
Low probability events are peddled everyday by salesmen, politicians,
and others who have public agendas.
It's everywhere and has probably been
around forever: bomb shelters in
the 1960s, duct tape, and plastic more
recently, lotteries, water purity, antibiotic counter cleaners, CRT radiation.
I'm sure you can think of more.
Conversely, other very serious
risks are downplayed or simply
ignored. According to the Department
of Transportation ( www.dot.gov),
17,400 people died in traffic accidents
in 2002. CBS News (www.cbsnews.
com), referencing the World Health
Organization, pointed out that
4,900,000 people died from tobacco-related illnesses worldwide in 2002
alone — nearly five million people! A
recent Washington Post story says,
"According to the Harvard Center for
Risk Analysis, the annual odds of
dying of heart disease are 1 in 397 ...
cancer are 1 in 511 ... car accident are
1 in 6,745 ... homicide are 1 in 15,440
... bioterrorism are 1 in 56,424,800."
The point I'm trying to make is
that proper risk assessment starts
with an individual who is willing and
able to analyze a situation and come to
a reasonable conclusion about what to
expect. Engineers are supposed to be
good at doing exactly this. Engineers,
as a group, have analytical minds and
are independent. Unfortunately,
engineers are people, too; it's easier
not to think. I should also say that such
fundamental risk assessments don't
require a pencil and paper. It's just a
basic understanding of probability and
statistics. (There are lots of good
books on various aspects of risk.)
NUTS & VOLTS
Circle #151 on the Reader Service Card.
As I said before, the most important elements in safety are knowing
and thinking. Common sense goes a
long way. I like the saying, "The most
dangerous tool is the one in your
hand." Don't force tools to do
something they weren't designed to
do. Don't try to drill glass with regular
bits. Don't measure high voltage with
a low-voltage probe. Stop and think.
Don't wear metal jewelry on your
hands or wrists when reaching into
something electrical. Obviously, they
can touch contacts and conduct
electricity into you. Worse, there is
generally more sweat under the metal
because the perspiration can't evaporate. This salt water creates a low
conductivity path and can significantly increase current through the flesh.
Just because the voltage is low
doesn't mean you are safe. A mechanic
was changing a starter switch in a car
and didn't disconnect the battery. His
ring touched the power terminal of the
switch and the chassis at the same
time. The full power of the battery
surged through the ring. It first
welded it in place and then it heated it
red hot. The results weren't pleasant.
Don't work alone with anything
that can get you into trouble. You
may not need to have someone
looking over your shoulder, but
someone should be within shouting
distance. Don't rely on a cell phone. If
you're out cold, you can't make a call.
For example: A worker got in early to
do some drywall work, but, when he
removed a piece of drywall from a
stack which was leaning against a
wall, the stack fell over onto him. He
was pinned for over two hours until