Sunday, October 14, 2007

Cleaning sprays cause asthma?

Asthma can be triggered by many things so it is not suprising to find that some household sprays may trigger it in some people. The claim that one in seven asthma cases could be accounted for by cleaner use is however an excessive extrapolation. Many of the asthma sufferers concerned presumably did lots of other things as well as clean their houses so how can we know that it was their use of cleaning products that was the critical factor? And maybe big users of cleaners are obsessional or neurotic personalities who do other crazy and unhealthy things and it is those things that cause the problem. Neurotic personalities certainly report more illnesses generally. Or maybe people who are already aware of a susceptibility to asthma (for familial or other reasons) use more cleaning products! One would in any case think that anyone who had an adverse reaction to a particular spray would stop using it! The effect must be very weak indeed if people are unaware of it: Asthma is a very conspicuous and distressing ailment with rapid onset. This would appear to be another data-dredged relationship with causal inferences made purely on faith. Abstract here

Using cleaning sprays and air fresheners while doing housework could account for up to one in seven cases of asthma in adults, a study has found. The modern penchant for using labour-saving cleaning sprays and air fresheners has been found to raise significantly the risk of symptoms. Just spraying a cleaner once a week can trigger an attack, according to the research. The risk rose the more that the sprays were used. "Frequent use of household cleaning sprays may be an important risk factor for adult asthma," said Jan-Paul Zock, of the Municipal Institute of Medical Research, in Barcelona. "The relative risk rates of developing adult asthma in relation to exposure to cleaning products could account for as much as 15 per cent, or one in seven, of adult asthma cases."

Furniture sprays, glass-cleaners and air freshener sprays were associated with the highest risk of a person developing asthma after doing the housework. No link was identified between the onset of asthma and the use of cleaning products that were not sprayed. Cleaning sprays have previously been found to be associated with an increased incidence of asthma among people who clean for a living but it is thought to be the first time the link has been made to everyday use.

Howard Stoate, a GP, MP and chairman of the asthma all-party parliamentary group, said that a link between chemicals and asthma has long been suspected. He hoped that it might explain why countries such as New Zealand, which have low air pollution levels, have increases in asthma levels. "There are a lot of gaps in our knowledge about asthma. Anything that fills those has to welcomed. Although asthma is on the increase worldwide no one can say why," he said.

Asthma UK, a charity dedicated to helping the 5.2 million asthma patients in Britain, said that it was particularly interested in the finding that people without asthma go on to develop it after using the sprays. "This report . . . highlights significant findings regarding the link between asthma and the use of spray cleaning products in the home," Victoria King, of Asthma UK, said. "Although further research is needed, we do already know that air fresheners and bleach trigger symptoms in people who already have asthma."

The international study involved 3,503 people aged 20 to 44 in ten European countries who used cleaning and air freshener sprays. Their details were first logged, on average, nine years before they were interviewed by the study team. Two-thirds were women but only 9 per cent were, at the end of the survey period, looking after the home full time. It was found that 6 per cent of the subjects had developed asthma symptoms and that there was a link between the disease and using sprays in the home at least once a week. Analysis revealed that using the sprays at least once a week, as 42 per cent of the study group did, increased the risk of asthma symptoms by 30 to 50 per cent.

The study team reported: "Consistently positive associations for most asthma definitions were observed for cleaning sprays in general, and glass-cleaning, furniture and air-refreshing sprays in particular." Cleaning sprays and air fresheners contain chemicals such as ammonia, chlorine-releasing agents and sodium hydroxide. Researchers suggested that the chemicals being released into the air in spray form significantly increased their exposure to people.

The results of the study were published in the American Journal of Respiratory and Critical Care Medicine, by the American Thoracic Society. The researchers used data from the European Community Respiratory Health Survey, one of the largest epidemiologic studies of airway disease in the world. A spokesman for the UK Cleaning Products Industry Association said: "The safety of consumers is the highest priority of our industries and the safety of our products is regularly checked and subject to rigorous controls, as well as stringent European legislation."


Getting a cold while pregnant causes your baby to be schizophrenic or autistic??

It's a wonder there is anybody normal. I think the report below is another reason why we should be skeptical of mouse studies and their generalizability

A mother's flu could hold the key to whether her child is born with schizophrenia or autism, a team of Caltech biologists announced Tuesday. Working with mice that carry the genes for a schizophrenia-like condition, the researchers found that the health of newborn mice depended on whether or not their mothers had an immune response to illness during pregnancy. Baby mice born to mothers who had become ill, the scientists showed, had the behavioral and brain abnormalities of a schizophrenic or autistic human. Those from mothers whose immune response to the flu had been blocked did not.

The experiments were based on previous studies that showed schizophrenia is more common among people born in the winter or spring or after influenza epidemics. Some research suggests that even one respiratory infection in a mother's third trimester can multiply her child's risk of schizophrenia three to seven times. "The work is extremely solid and very interesting," Dan Geschwind, a UCLA neurogeneticist, said Tuesday of the Caltech team's work. "There are some things that are very unexpected."

The schizophrenia-causing culprit was a protein in pregnant mice's immune response known as interleukin-6, or IL-6, the Caltech researchers found. "In the mouse model, if you block the protein IL-6, you completely normalize the behaviors of the offspring," said Paul Patterson, a Caltech biologist. "On the converse experiment, if you just inject IL-6 into the mother, that will give rise to offspring with abnormal behaviors. "It doesn't mean there wouldn't be other proteins that would be involved, but it does mean that this one is really critical," he said.

That a single injection of IL-6 during the middle of gestation would cause behavioral deficits was "amazing," Geschwind said. "Nobody's ever shown that this can happen," he said. As in people with autism and schizophrenia, the affected mice had problems with social interaction, anxiety and attention span, Patterson said.

Finding the link between a pregnant mouse's immune response and her newborn's mental health is the first step, Geschwind said, to understanding whether there could be a similar biological connection in humans. The scientists still don't know what it is about the IL-6 protein that could be wrecking havoc in the newborns' brains, but they have some theories. "Now we're trying to find where this protein acts," Patterson said. "Does it act on the placenta or does it act on the fetal brain itself?" The protein could be limiting the passage of oxygen or nutrients through the placenta, he said. Alternately, it could affect the production or movement of new brain cells or cause inflammation in the fetus' brain. "We tend to think of the cold or the flu as a minor annoyance, but for pregnant Women it's really not," Patterson said. "I think not just our work, but the previous work, emphasizes the importance of infection in pregnancy."

However, he added, a genetic predisposition to the mental disorders was required for the protein to have its dire effect. "That would explain why everybody who gets an infection doesn't have schizophrenic offspring," he said.



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].

Trans fats:

For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.


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