Pesticides causing brain cancers in children

Pesticides blamed for some childhood brain cancers.
Apr 07, 2009


Shim Y, SP Mlynarek and E van Wijngaarden. Parental exposure to pesticides and childhood brain cancer: United States Atlantic Coast Childhood Brain Cancer Study. Environmental Health Perspectives doi:10.1289/ehp.0800209.

Synopsis by Heather Hamlin


Little is known conclusively about what causes brain cancer in children, but research studies are consistently finding links to prebirth pesticide exposure.


A new study finds that children who live in homes where their parents use pesticides are twice as likely to develop brain cancer versus those that live in residences in which no pesticides are used. Herbicide use appeared to cause a particularly elevated risk for a certain type of cancer.
This study highlights a new and compelling reason to avoid or limit pesticide use and take necessary precautions during exposure. It also adds to a growing body of research that finds that pesticide exposure -- especially with farm life and pesticide use -- might be contributing significantly to this deadly disease.

Brain cancer is the second most common cancer in children, yet why it develops is not clear. Genetics plays a role in some cases, but researchers believe those not due to associated genes are related to environmental factors and exposures.

The authors explain that "parental exposures may act before the child’s conception, during gestation, or after birth to increase the risk of cancer." Exposures at each time period may trigger different changes that lead to cancers, such as genetic mutations or changes in gene expression or hormone and immune function.
The study evaluated more than 800 fathers and more than 500 mothers that lived in residential areas in four Atlantic Coast states (Florida, New Jersey, New York (excluding New York City) and Pennsylvania). Researchers match and compare every person that is "exposed" to an "unexposed" person of the same age and status. In this case, more than 400 fathers and 250 mothers of exposed children were included.

Researchers assessed -- through telephone interviews with the mothers -- parental exposure to insecticides, herbicides, and fungicides at home and at work beginning two years prior to their child's birth.

Brain cancer cases in children under 10 years old, diagnosed between 1993 and 1997, were included in the study. The children had participated in the original Atlantic Coast childhood brain cancer study. Their illnesses represented a range of cancers, including astrocytomas and primitive neuroectodermal tumours (PNET). Astrocytomas was associated with herbicide use in this study.

The risk of childhood brain cancer was significantly lower for fathers who washed immediately after the pesticide exposure or wore protective clothing versus those who never or only sometimes took precautions.

The parents assessed in this study were generally in contact with the pesticides through residential exposure, including lawn and garden care.

Pesticides increase Parkinson's risk

(NaturalNews) A new study has provided one of the strongest links yet between pesticide use and Parkinson's disease.

A team of researchers from Duke University, Miami University and the Udall Parkinson's Disease Research Center of Excellence has found that people who were exposed to pesticides were substantially more likely to develop Parkinson's disease than closely related people who did not use so many pesticides, according to a study published in the journal BMC Neurology.

Parkinson's disease is a degenerative neurological condition resulting from the damage or death of the brain cells that regulate muscular movement. When cells become unable to produce the neurotransmitter dopamine, a wide variety of problems, such as slurred speech, stiffness, tremors, and problems with balance and movement, occur. Approximately one million people in the United States - one in 300 - suffer from the disease. In the United Kingdom, approximately one in 500 people, or 120,000 people, are affected.

The researchers surveyed 319 people with Parkinson's disease on their pesticide use, and compared that use to more than 200 healthy family members and other unaffected people. The purpose of comparing relatives was to control as much as possible for genetic and non-pesticide environmental factors by looking only at people with similar backgrounds.

"Previous studies have shown that individuals with Parkinson's disease are over twice as likely to report being exposed to pesticides as unaffected individuals," lead researcher Dana Hancock said, "but few studies have looked at this association in people from the same family or have assessed associations between specific classes of pesticides and Parkinson's disease."

People who had been exposed to pesticides had 1.6 times the Parkinson's risk of people who had not been exposed, while those exposed for more than 200 days in a year had more than two times the risk. The pesticides with the strongest connection to Parkinson's disease were insecticides and herbicides. Home and garden exposure were more strongly linked to increased risk than occupational use.

Broken down by sex, men who frequently used pesticides were 2.15 times more likely to develop the disease than men who did not use the chemicals, while women were 2.43 times more likely.

The researchers also compared rates of well-water drinking and living or working on a farm between people with and without the disease. They did not find a correlation between Parkinson's disease and any of these behaviors, which are commonly used as surrogate measures of pesticide exposure. Instead, the effect turned up only when they looked directly at chemical exposure.

Scientists have known for some time that the risk of Parkinson's disease is influenced by genetics, but the gene defects that have been linked to the disease account for only a small fraction of cases. Environmental factors have also been implicated, particularly in light of the fact that the disease was mostly unknown prior to the industrial revolution but has become a common ailment since then.

Prior studies have found links between pesticide exposure and Parkinson's risk, but they have not been thought conclusive. Kieran Breen, director of research at the Parkinson's Disease Society, cites a study of 10,000 Parkinson's patients that found only 1,000 had been exposed to pesticides over the long-term. The current study, Breen said, "strengthened the fact that pesticides play a key role" in risk of the disease.

"I think there is very strong evidence now linking [pesticide exposure and Parkinson's risk,]" Hancock said. The next step, Hancock said, is to discover the biological mechanisms by which pesticides increase the risk of the disease.

The findings of another study on the links between Parkinson's and pesticides, commissioned by the British Department of Environment, Food and Rural Affairs, are expected this summer.
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Home -grown vegetables poisoned with pesticides!

Home-grown veg ruined by toxic fertiliser

Gardeners across Britain are reaping a bitter harvest of rotten potatoes, withered salads and deformed tomatoes after an industrial herbicide tainted their soil.
Caroline Davies reports on how the food chain became contaminated and talks to the angry allotment owners whose plots have been destroyed

What's the solution? Join the debate and find out more on our food blog

Caroline Davies The Observer, Sunday June 29, 2008
http://www.guardian.co.uk/environment/2008...ood.agriculture


Mass spraying of pesticides on farms, pictured here in Florida, is putting gardens at risk. Photograph: David R. Frazier/Alamy

Gardeners have been warned not to eat home-grown vegetables contaminated by a powerful new herbicide that is destroying gardens and allotments across the UK.

The Royal Horticultural Society (RHS) has been inundated with calls from concerned gardeners who have seen potatoes, beans, peas, carrots and salad vegetables wither or become grossly deformed. The society admitted that it had no idea of the extent of the problem, but said it appeared 'significant'. The affected gardens and allotments have been contaminated by manure originating from farms where the hormone-based herbicide aminopyralid has been sprayed on fields.

Dow AgroSciences, which manufactures aminopyralid, has posted advice to allotment holders and gardeners on its website. Colin Bowers, Dow's UK grassland marketing manager, told The Observer that links to their products had been proved in some of the cases, but it was not clear whether aminopyralid was responsible for all of them and tests were continuing. 'It is undoubtedly a problem,' he said, 'and I have got full sympathy for everyone who is involved with this.'

He said the company was unable to advise gardeners that it was 'safe' to consume vegetables that had come into contact with the manure because of pesticide regulations. 'All we can say is that the trace levels of aminopyralid that are likely to be in these crops are of such low levels that they are unlikely to cause a problem to human health.'

The Dow website says: 'As a general rule, we suggest damaged produce (however this is caused) should not be consumed.' Those who have already used contaminated manure are advised not to replant on the affected soil for at least a year.

Aminopyralid, which is found in several Dow products, the most popular being Forefront, a herbicide, is not licensed to be used on food crops and carries a label warning farmers using it not to sell manure that might contain residue to gardeners. The Pesticides Safety Directorate, which has issued a regulatory update on the weedkiller, is taking samples from affected plants for testing.

Problems with the herbicide emerged late last year, when some commercial potato growers reported damaged crops. In response, Dow launched a campaign within the agriculture industry to ensure that farmers were aware of how the products should be used. Nevertheless, the herbicide has now entered the food chain. Those affected are demanding an investigation and a ban on the product. They say they have been given no definitive answer as to whether other produce on their gardens and allotments is safe to eat.

It appears that the contamination came from grass treated 12 months ago. Experts say the grass was probably made into silage, then fed to cattle during the winter months. The herbicide remained present in the silage, passed through the animal and into manure that was later sold. Horses fed on hay that had been treated could also be a channel.

Bryn Pugh, legal consultant at the National Society of Allotments and Leisure Gardeners, said he was preparing claims for some members to seek financial compensation from the manure suppliers. But it was extremely difficult to trace the exact origins of each contaminated batch. 'It seems to be everywhere. From what I know, it is endemic throughout England and Wales. We will be pressing the government to ban this product,' he said.

Aminopyralid is popular with farmers, who spray it on grassland because it controls weeds such as docks, thistles and nettles without affecting the grass around them. It binds itself to the woody tissue in the grass and only breaks down when exposed to bacteria in the soil.

Shirley Murray, 53, a retired management consultant with an allotment near Bushy Park in Hampton, south-west London, said several of her allotment neighbours had used the same manure bought from a stables and all were affected. 'I am absolutely incensed at what has happened and find it scandalous that a weedkiller sprayed more than one year ago, that has passed through an animal's gut, was kicked around on a stable floor, stored in a muck heap in a field, then on an allotment site and was finally dug into or mulched on to beds last winter is still killing "sensitive" crops and will continue to do so for the next year,' she said.

'It's very toxic, it shouldn't get into the food chain. You try to be as organic as you can and we have poisoned ourfood. I've been everywhere, emailed all the right people, but nobody will speak on the record to guarantee what is safe to eat. We all think it is a scandal. Not to mention what it has cost in time and money.'

Pesticide expert Professor Vyvyan Howard, a toxico-pathologist at Ulster University, said it was 'a very powerful herbicide' but in his opinion was 'unlikely to pose any human health risks'. However, advice about its use should be strengthened, he said. 'I think the thing that is going to drive this is the commercial damage that could be done to market gardeners,' he said.

Guy Barter, the RHS head of horticultural advisory services, said they were receiving more than 20 calls a week. 'Our advice is not to eat the vegetables because no one seems to have any idea whether it is safe to eat them and we can't give any assurances,' he said. 'It is happening all over the country. A lot of cases we are seeing is where people have got manure from stables and the stable have bought their hay from a merchant, and the merchant might have bought hay from many farmers, possibly from different parts of the country. So they have no idea where the hay came from. So finding someone to blame is quite difficult.' Weedkiller in the soil should dissipate by next year, but in stacks of contaminated manure it might take two or more years to decay, he added.

Dow is planning a major publicity campaign to reiterate warnings to farmers over usage, and to encourage allotment holders to check the provenance of manure that they put down in an effort to prevent the problem escalating. On compensation, it was less forthcoming. 'There is no easy answer to that,' said Bowers. 'The first port of call is always where the manure comes from. From that point on, I can't really comment.

'The chain is horrendously complicated. In the cases we have managed to trace back, we might find that the farmer who supplied the manure didn't spray anything himself, but he might have bought in a couple of bales of silage from one of his neighbours, and that farm might have sprayed.'

Robin and Christina Jones spread a large amount of manure over their flower garden and vegetable patch at their home in Banstead, Surrey. When the potatoes failed, Robin took a sample to the RHS, which identified aminopyralid. His neighbour, who bought from the same source, suffered the same problems. 'We have lost 80 per cent of our vegetable patch,' said Jones, 65, a retired sound engineer. Raspberries, French beans, onions, leeks, even a newly planted robina tree were all affected. 'We are distraught. But what worries me is that the courgettes look very healthy. Had we not had the problem with the potatoes, we might never have realised. Now we are advised not to eat them.

'This is a very serious issue, and people must be made aware of the advice not to eat vegetables grown in contaminated manure.'

Sue Ainsworth, 58, an education consultant, said around 20 allotments at her site in Hale, Cheshire, had been affected. 'We first noticed with the potatoes. As they came through, they were deformed, all curled over and rotten underneath. But the worry is that the courgettes also planted on the manure are fine - but are they safe to eat? This must have affected thousands of people. I am really worried about this product and really think it should be withdrawn.'

She said the farmer who supplied the manure said he had used nothing unusual. 'But he may have bought in the straw and genuinely knew nothing about the herbicide used.'

Susan Garrett, 57, an IT consultant, said 20 plots were affected at her allotment in Wakefield, West Yorkshire. 'And that is just the plants we can see are damaged. We are angry it has been allowed to happen - not with the chemical company, but because there doesn't seem to be any protection for us or anything to stop it happening again.'

Toxic pollen

Toxic pollen from genetically modified corn kills monarch butterflies, researchers find in lab tests

By Blaine P. Friedlander Jr.
http://www.news.cornell.edu/chronicle/99/5...xic_pollen.html

An increasingly popular commercial corn, genetically engineered to produce a bacterial toxin to protect against corn pests, has an unwanted side effect: Its pollen kills monarch butterfly larvae in laboratory tests, according to a report by Cornell researchers.

Writing in the May 20 issue of the journal Nature, the researchers note that this hybrid crop, known as Bt-corn, has genes from the bacterium Bacillus thuringiensis (Bt) spliced into the plant genes. These hybrids are very effective against the ravenous European corn borer, a major corn pest that is destroyed by the plant's toxic tissue. The engineered corn is safe for human consumption.

Unlike many pesticides, the Bt-corn has been shown to have no effect on many "nontarget" organisms -- pollinators such as honeybees or beneficial predators of pests like ladybugs. But the Bt-modified corn produces pollen containing crystalline endotoxin from the bacterium genes. When this corn pollen is dispersed by the wind, it lands on other plants, including milkweed, the exclusive food of monarch caterpillars and commonly found around cornfields.



John E. Losey, Cornell assistant professor of entomology and the primary investigator on the study, said: "We need to look at the big picture here. Pollen from Bt-corn could represent a serious risk to populations of monarchs and other butterflies, but we can't predict how serious the risk is until we have a lot more data. And we can't forget that Bt-corn and other transgenic crops have a huge potential for reducing pesticide use and increasing yields. This study is just the first step; we need to do more research and then objectively weigh the risks versus the benefits of this new technology."

Like all grasses, corn is wind-pollinated, and the pollen can be blown more than 60 yards from the edge of cornfields. "Pollen is that yellow dusting your car gets on spring and summer days; pollen is everywhere," explained Losey. "That's why we are concerned about this problem."

Other researchers on the study were Linda S. Rayor, Cornell instructor in entomology, and Maureen E. Carter, Cornell research aide.

"Monarchs are considered to be a flagship species for conservation. This is a warning bell," said Rayor. "Monarchs themselves are not an endangered species right now, but as their habitat is disrupted or destroyed, their migratory phenomena is becoming endangered."

In the laboratory tests, monarchs fed milkweed leaves dusted with so-called transformed pollen from a Bt-corn hybrid ate less, grew more slowly and suffered a higher mortality rate, the researchers report. Nearly half of these larvae died, while all of the monarch caterpillars fed leaves dusted with nontransformed corn pollen or fed leaves without corn pollen survived the study.

The toxin in the transformed pollen, the researchers say, goes into the gut of the caterpillar, where it binds to specific sites. When the toxin binds, the gut wall changes from a protective layer to an open sieve so that pathogens usually kept within the gut and excreted are released into the insect's body. As a result, the caterpillar quickly sickens and dies.

Bt-engineered corn is among the first major commercial successes for agricultural biotechnology. Last year, more than 7 million acres of the hybrid crop were planted by U.S. farmers primarily to control the European corn borer. Before the advent of Bt-corn, this pest was extremely difficult to control because it bores into the stalk, where it is protected from pesticides. It produces several generations a year. Because it was so difficult to control effectively with pesticides, annual losses averaged $1.2 billion.

In contrast, Bt-corn provides essentially total season-long control at a reasonable cost without the use of pesticides. At least 18 different Bt-engineered crops have been approved for field testing in the United States. As of last year, transformed corn, potatoes and cotton had been approved by the U.S. Department of Agriculture for commercial use.

Several factors make monarch caterpillars particularly likely to make contact with corn pollen, Losey said. Monarch larvae feed exclusively on milkweed because it provides protection against predators. The plant contains cardenolides, which are toxic, bitter chemicals that the monarch caterpillar incorporates into its body tissues, rendering it unpalatable to predators. Milkweed grows best in "disturbed" habitats, like the edges of cornfields, Losey noted.

The butterflies overwinter in Mexico and by the spring begin migrating north. The first generation of the year crosses into Texas, other Gulf Coast states and Florida, seeking milkweed on which to lay their eggs and feed. By late May or early June, the second generation of adults has emerged and heads north to areas including the Midwest Corn Belt. Monarch caterpillars are feeding on milkweed during the period when corn is shedding pollen, Losey said. Thus "they may be in the right place at the right time to be exposed to Bt-corn pollen."


May 20, 1999