I've heard that bug zappers can actually help transmit
diseases -- how does that happen? Once the mosquito dies, how
can a disease it was carrying be transmitted?
According to recent research, it is true that bug zappers
can end up transmitting the diseases carried by the insects
Two Kansas State University researchers, James Urban and
Alberto Bruce, carried out a study of this effect. They
contaminated house flies with bacteria or viruses either
externally (by way of an aerosol spray) or internally (by
feeding them sucrose solutions containing the bacteria or
virus). They then released the flies into a chamber where a
bug zapper was mounted and sampled the air at various
distances from device.
What they found was that the air around the bug zapper was
contaminated with bacteria and virus particles from the
electrocuted flies (externally-contaminated flies released
more bacteria and virus particles than internally-contaminated
flies). Other research has shown that bug zappers can spread a
mist containing insect parts up to about 7 feet (2 m) from the
device. Urban and Bruce concluded that bug zappers pose a
health risk because of the release of bacteria, viruses and
potential allergens (insect parts) into the surrounding air.
Therefore, if you plan to use a bug zapper at your next
picnic or barbecue, it is probably wise to place it at least
12 feet (3.6 m) away from areas where food is prepared or
eaten and where children play.