Researchers have created a genetically
modified mosquito. Rebecca Williams reports the
scientists hope the mosquito will help save lives:
Transcript
Researchers have created a genetically
modified mosquito. Rebecca Williams reports the
scientists hope the mosquito will help save lives:
Malaria kills more than one million people every year. The disease is
spread by mosquitoes.
Marcelo Jacobs-Lorena is a researcher at Johns Hopkins Malaria
Research Institute. He’s part of a team that has bred a genetically
modified mosquito. It can’t get infected by the malaria parasite.
“If we go to a region where malaria is prevalent and we are able to
substitute the local mosquito population by the modified mosquito that
cannot carry the parasite, then the net effect will be interruption of
transmission.”
Jacobs-Lorena says they’re confident the super mosquito is safe to
release into the wild.
But he says they’ll have to convince a lot of people that it’s okay to let it
out of the lab.
The USDA is testing a new bug spray to ward off mosquitos and other pests (Photo by Lester Graham)
Researchers are working on new chemicals
to keep mosquitoes from biting. The Environment
Report’s Mark Brush reports they might have found
a better alternative to DEET:
Transcript
Researchers are working on new chemicals
to keep mosquitoes from biting. The Environment
Report’s Mark Brush reports they might have found
a better alternative to DEET:
The EPA says DEET is safe to use on your skin. But the repellent’s smell and stickiness
turns some people off. And spraying DEET on your skin won’t protect you from all types
of mosquitoes.
So researchers are working on alternatives.
Uli Bernier is research chemist with the USDA. He says their research team is looking
for a compound that will work against some of the most dangerous mosquitoes.
“DEET works against a great variety of insects, but not against all of them. And in
particular some of the malaria transmitting mosquitoes will bite through DEET without
difficulty.”
Bernier says their research has turned up some chemicals that do a better job than DEET.
The chemicals keep mosquitoes from biting for up to three times longer. Bernier says their
next step will be to test the chemicals for possible human health effects and for their
effectiveness on other insects.
(mosquito buzzing sound)
For The Environment Report (sound of swat) – gotcha – I’m Mark Brush.
A new study says modern humans are in the evolutionary fast lane. Scientists say world
population growth is leading to beneficial genetic mutations. Chuck Quirmbach has
more:
Transcript
A new study says modern humans are in the evolutionary fast lane. Scientists say world
population growth is leading to beneficial genetic mutations. Chuck Quirmbach has
more:
Some scientists contend modern culture and conveniences have basically halted human
evolution. But anthropologist John Hawks says that’s not so. He’s been analyzing data
from an international gene-cataloguing study. He says many genes have rapidly changed
within the last 5-thousand years. For example, Hawks says one positive development is
that humans have more genes that fight off some diseases:
“Things that resist malaria, things that resist smallpox, things that are resistant to new
diseases that have emerged in the last 10,000 years.”
Hawks says there have also been changes related to what some groups can eat and drink,
for example, many northern Europeans can now drink milk their whole lives. The study
of genetic change is published in the Proceedings of the National Academy of Sciences.
A recent report looked at the potential health effects of climate change on people in the Niagara region. The report predicts increased exposure to malaria, dengue fever and yellow fever in coming years. The report was released by the environmental group Pollution Probe, and was done in partnership with the health and environment departments of the Canadian government. The Great Lakes Radio Consortium’s Dan Karpenchuk reports:
Transcript
A recent report says people in the Niagara region expect increased exposure to malaria, dengue fever and yellow fever in coming years because of climate change. The warning is contained in a new report by the environmental group, Pollution Probe. The report was done in partnership with the health and environment departments of the Canadian government. The Great Lakes Radio Consortium’s Dan Karpenchuk reports from Toronto:
The report says the diseases are projected to spread because climate change favors the northward movement of disease carrying birds, insects and rodents. Quentin Chiotti of Pollution Probe says the sudden spread of the West Nile Virus is an example of what to expect.
“Now though, there’s some uncertainty about predicting just when that will happen, without a
doubt the conditions are going to be ripe for these kinds of disease outbreaks.”
Chiotti says there are already twenty confirmed cases of the West Nile Virus in Canada, compared
to none last year. And more than three thousand in the U.S.
Chiotti also says the number of excessive heat days could double to thirty each summer by the
year 2030. He says that could lead to more deaths – as many as four hundred people each
summer in the region.
Pollution Probe says the predictions show the need to tackle greenhouse gas emissions as soon as
possible.
For the Great Lakes Radio Consortium, I’m Dan Karpenchuk in Toronto.
The Culex pipiens quinquefasciatus
mosquito - one of the mosquitoes responsible for the transmission of West Nile virus. Photo courtesy of the USGS.
The West Nile virus has claimed 28 lives and at least 550 people have been infected in the nation so far this summer. And evidence of the virus has already been found in 41 states. The carriers of the virus, mosquitoes, have been a concern and a nuisance for public health officials. Many citizens are demanding more visible action on the officials’ part to get rid of the bad bugs…like spraying chemicals to kill adult mosquitoes. The Great Lakes Radio Consortium’s Annie MacDowell reports:
Transcript
The West Nile virus has claimed 28 lives and at least 550 people have been infected in the nation so far this summer. And evidence of the virus has already been found in 41 states. The carriers of the virus, mosquitoes, have been a concern and a nuisance for public health officials. Many citizens are demanding more visible action on the officials’ part to get rid of the bad bugs…like spraying chemicals to kill adult mosquitoes. The Great Lakes Radio Consortium’s Annie MacDowell reports:
You might not expect to find a breeding ground of controversy in the suburbs, but
then again, you wouldn’t expect to find an exotic disease breeding there, either.
With the West Nile virus threatening any place that has mosquitoes…which is almost
anywhere…people are fighting over whether to spray or not to spray.
Spraying means releasing pesticides into the air to kill adult mosquitoes.
Pro-sprayers say the threat of West Nile virus necessitates this chemical
treatment. But some people who live in spraying districts are worried about the
possible dangers of the pesticides. Dr. Kim Stone is the Executive Director of the
Safer Pest Control Project in Chicago. As we walk around a nature preserve, she
tells me they’ve started spraying in her neighborhood and she’s worried about her
kids. Passing the pond and a grove of trees, she says the pesticides could kill fish
that eat mosquito larvae and birds that eat the adults. But she’s more concerned
about their possible threat to humans.
“I believe that the health impacts of the pesticides are a greater danger than the health impacts of West Nile virus. A local hospital had seen many people who thought that they had West Nile virus, came in with headache, nausea, and the hospital said that they did not have West Nile virus, but suspected that it might be related to the pesticides, because it was the morning after pesticides were sprayed in those neighborhoods.”
Stone recommends a different form of mosquito abatement…larvaecide.
Larvaecide is a preventative form a treatment that kills mosquito larvae before they
hatch. Pellets of larvaecide are dropped into lagoons, or a blower is used to spread
granules over the water. The chemicals are less toxic, she says, and they’re
species-specific. That means they won’t kill other animals. Dr. William Paul is with
the Chicago Department of Public Health. He says the city of Chicago hasn’t started
spraying because larvaecide is much more effective.
“We would really, in terms of mosquito control, want to focus on the long run,
breeding sites, and larval breeding sites, because that’s in the long run what’s going to be more effective. Using sprays for adults to kill the northern house mosquito… it’s challenging, you need tightly spaced applications of the product. And it’s not just a going up and down the streets kind of thing.
But spraying is a more visible treatment than larvaecide. Paul says people like to
see their government doing something to combat the mosquitoes. It makes them
feel better, he says. Other government officials can relate. Dr. Kiahn Liem has
been the head of the South Cook County Mosquito Abatement District in the Chicago area for 28 years. He’s has been working with mosquitoes since he was a little boy. He says watching many of his fathers’ patients die of malaria in his native country led him to his current profession of killing mosquitoes.
“I grew up in Indonesia, and malaria is a big killer of people there. Almost six to ten million people every year get killed by malaria. And there’s probably ten times more mosquitoes there than here.”
Liem uses larvaecide in his district. He hasn’t sprayed since 1977, after the
outbreak of St. Louis encephalitis, another virus carried by mosquitoes. He says
spraying was not effective then, and it still isn’t now, as most mosquitoes hide out in
people’s back yards, in the bushes or under leaves. He says the spray released from
trucks in the street just doesn’t reach them. But many of his citizens demand a
visible fight against the mosquitoes.
“They want to see you working. But if you work and you don’t do anything for them, you’re just fooling them. We have many of them that call us, and say, I want you here, I want you to show me that you’re doing something for my money. And we do that just to appease them.”
If people really want peace of mind, personal protection is what most experts
recommend. They say to wear long sleeves and pants between dusk and dawn
when mosquitoes are out in force. If you’re going outside, use mosquito repellent.
And routinely change standing water on your property, such as kiddie pools and bird
baths, to cut down on available mosquito breeding sites.
For the Great Lakes Radio Consortium…I’m Annie MacDowell.
(Photo courtesy of the US Geological Survey)
