Almost one-third of adult U.S. women have hypertension, according to the Centers for Disease Control and Prevention.
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Women exposed before birth to the banned pesticide DDT may have a greater risk of developing high blood pressure later in life, according to a study published today.
The study of San Francisco Bay Area women is the first to link DDT exposure in the womb to hypertension, which raises the risk of stroke and heart disease.
A widely used insecticide, DDT was banned in the United States in 1972 because it was building up in the environment. It is still used in Africa to combat malaria-infected mosquitoes.
“Our findings suggest that DDT may be targeting the system in the body that keeps blood pressure under control,” said Michele La Merrill, a toxicologist at the University of California, Davis and lead author of the study published today in Environmental Health Perspectives.
In previous research, pesticide applicators with high blood pressure had higher DDT exposures than those with healthy blood pressure. Research also has suggested that DDT interferes with hormones, and it has been linked to decreased fertility, preterm delivery and diabetes.
In the new study, more than 500 women born between 1959 and 1967 participated. They were the daughters of more than 15,000 women from the Oakland area who were recruited by scientists to investigate how environmental exposures, even those that occur before birth, can affect health over a lifetime.
Because DDT can pass to the child through the placenta, the blood of the mothers, collected shortly before or after birth, served as a proxy for fetal exposure.
Several decades later, 111 of the daughters, 21 percent, reported having been diagnosed with hypertension.
Overall, the women in the highest two-thirds of prenatal DDT exposure were 2.5 to 3.6 times more likely to develop high blood pressure before age 50 than women in the lowest one-third of exposure.
“We are now seeing the potential long-term health consequences of introducing chemicals whose safety we know very little about,” said Jonathan Chevrier, an environmental health scientist at the University of California, Berkeley, who did not participate in the new study.
Almost one-third of adult U.S. women have hypertension, according to the Centers for Disease Control and Prevention. Prevalence in postmenopausal women is much greater than in premenopausal women.
The researchers found that the association between DDT and high blood pressure held after accounting for some factors known to raise the risk of hypertension, including age, race, body mass and diabetes status.
However, it is unclear how factors they did not test, such as how much salt a person eats, may have affected the findings.
It also is impossible to know whether some women had undiagnosed high blood pressure or how blood pressure levels differed across exposure groups.
“The degree of hypertension matters in terms of clinical significance, so from a clinical perspective it’s hard to say anything about the relative importance of the findings,” said Dr. Ted Schettler, science director of the Science and Environmental Health Network, a non-profit organization.
However, he added, “anything that raises the blood pressure of an entire population, even a small amount, can have large public health consequences.”
DDT breaks down slowly, so most people alive today have traces in their bodies, and it remains in the environment and the food web.
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7 Comments
Add CommentAnd yet, I expect that the 655,000 who died from malaria in 2010, would have gladly taken that risk of high blood pressure.
Reply | Report Abuse | Link to thisRe: Postman1's comment: Yes, possibly, but you are comparing two different populations in very different parts of the world that are affected by very different epidemiological conditions. What were you implying? That high blood pressure risk is less morally or spiritually important than the risk of dying from malaria? The two are not comparable.
Reply | Report Abuse | Link to thispriddseren,
Reply | Report Abuse | Link to thisDid you read the study and can you give a real analysis of the weaknesses of this peer reviewed paper? I did read the study and find it quite compelling. Is it the final word on a possible link between DDT and hypertension? Of course not, more research is needed but there have been several studies over the decades that have already found a link between DDT and hypertension.
Also, do you know where the vast majority of malaria deaths occur in the world? Hint, it's not in areas where DDT has been banned. The assertion that banning DDT somehow reintroduced malaria into the world is, at best, a ridiculous one.
And yes, there are many reason to ban DDT that have all been well documented and studied. There is no need for anyone to "invent" a reason to continue the ban.
Postman1,
Reply | Report Abuse | Link to thisThe vast majority of deaths related to malaria occur in regions where DDT is NOT banned. The idea that the indiscriminate use of DDT could somehow eradicate malaria in the developing world has long been abandoned due to: Its cost, its declining effectiveness due to resistant populations that have arisen and better strategies being developed. There are still way too many deaths due to this scourge but the idea that the ban on DDT is somehow responsible has long been debunked. Of course that doesn't stop shills like John Stossel from making assertions that USAID does not fund DDT programs because they are afraid of the left.
The article says that about one third of women in USA have hypertension.
Reply | Report Abuse | Link to thisThis possible 3% due to DDT seems very tenuous going by what other unknown factors may be involved.
What is certain is that at the end of WW2 the Typhus etc raging in the Nazi Concentation Camps was controlled by DDT and it was used in delousing people in copious amounts.
View old newsreels of clouds of DDT around those being deloused.
It saved many thousands of lives then , and those saved would be very grateful for the lifegiving property of DDT.
Rachael with the Book "Silent Spring" did a good job of scaring those who are easily scared by such books.
Some birds are affected by DDT,not all .
Rather like Nuclear Power today.
It is a favorite sport of the Envirenmentals to predict widespread calamity from that form of Energy.
However if you look at how many die annualy from other forms it is really very safe.Repeat safe.
Fukashima and Chernoble taken into account.
I will continue to worry about the drunks and cell phone using morons out on the Highway.
However such articles keep the presses rolling and "investigatgive reporters" employed.
Health and Happiness to all.
Elderlybloke,
Reply | Report Abuse | Link to thisDon't forget that the conclusions of "Silent Spring" have been found to be quite sound; That the indiscriminate use of DDT was causing environmental and ecological damage and that perhaps we should study those effects before we just start throwing it all over the place. I generally tend to agree with you regarding nuclear power but that doesn't mean that we should turn a blind eye and just accept faulty implementations of nuclear power, Fukashima and Chernoble being notable examples.
Sorry elderlybloke, but when you say 'Some birds are affected by DDT, not all' that doen't invalidate the evidence that DDT is harmful to life.
Reply | Report Abuse | Link to thisThe birds most affected by DDT are the ones which have the most DDT in their bodies. And the reason for that is that the most affected birds are the ones at the top of the food chain, which have therefore accumulated the most DDT from all the other animals they've eaten, because DDT accumulates in body fat. Birds at the bottom of the food chain are less affected by DDT precisely because they don't have as much DDT in their bodies.
Yes of course DDT has also done many thousands or millions of people a service because DDT has killed insects which pass on some terrible diseases such as malaria. But DDT is not the only insecticide in existence, and using insecticides is not the only - or the best - way of preventing disease.
And you imply that high blood pressure is not such a terrible thing. The trouble is it can also lead to things like heart disease, strokes, and vascular dementia. None of these things are any fun at all.
If we want to live long, healthy lives which are not blighted by misery in the last few years then we need to keep our blood pressure down. There are many factors involved in high blood pressure, and we need to deal with all of them. Perhaps the legacy of DDT (still out there years after it was banned) is not the most important factor, but it helps to know about it.
There is an interesting parallel between this story and
http://www.scientificamerican.com/article.cfm?id=long-lasting-chemicals-may-harm-sea-turtles