Enough to make the blood boil
Seriously hazardous chemicals can be found in the tissue of nearly every person alive. It is a frightening thought, but exposure to such toxic substances has been linked to a higher incidence in several cancers, reproductive complications, a continuing decline in fertility rates and birth defects.
Like the majority of people, I was unaware of the levels of these chemicals circulating in my bloodstream, so when the opportunity to find out about them came along, I seized it.
Along with 150 others, from politicians and journalists to leaders of environmental NGOs and lobby groups, I volunteered to have my blood tested for three groups of dangerous chemicals, including PCBs, organochlorine pesticides and PBDEs, or flame-retardants.
The biomonitoring survey, which is the largest exercise the UK has seen in biomonitoring in over two decades, is part of a chemicals and health campaign set up by the environmental
It seeks to discover the extent of volunteers' contamination with the sort of chemicals and toxic substances that, largely without
consumers' knowledge, are routinely sprayed on crops and food, added to paints and home-decorating products, and used in everything from furniture and carports to computers and televisions.
In June, at the time the samples were taken, I did not imagine the analysis would turn up any particular nasties.
For the first 18 years of my life, from 1972, I lived in a village on the fringes of the countryside near the industrial town of Warrington, in Cheshire. Although in my early years the claimed health benefits of switching to organic food had yet to made, my parents were aware that agriculture was largely chemical-dependent, and our supermarket fruit and vegetables were always washed before being eaten.
I have since continued in the same vein of my upbringing, avoiding the expensive switch to organic, but conscious that supermarket fruit and vegetables may have residues of agricultural chemicals and should therefore be washed before eating.
I am also a carnivore, and although I am not unhappy if I do not get a daily dose of
something's cooked flesh, I eat a lot of what is likely to be intensively farmed chicken and, particularly, fish.
In short, as far as what I put into my body is concerned, I think I'm pretty healthy - but not perfect.
But external influences, or the impact of a person's surrounding domestic, work and leisure environment, can also affect their degree of toxicity. Since leaving home for university 13 years ago, I have lived in the comparatively polluted atmospheres of major cities, but I have never worked in any business close to the chemical industry.
My test results came back last week, detailing my exposure to 77 chemicals, along with the collective minimum, maximum and median of the other volunteers.
When the full results are published in full later this month, they will reveal that not one of the 150 participants had clean blood.
One fortunate individual showed detectable levels of only nine of the 77 substances measured. I had 19, and this was below average compared with a maximum of 49 and a median of 27.
All of the results for the chemicals found are given in "ng/g lipid" - which stands for nanograms of chemical per gram of fat tested. Put simply, this reveals how many thousand-millionths of a gram of chemical were found for every gram of my fat tested.
It sounds negligible, but there is a catch. Virtually nothing is known about the long-term effects on human health of these chemicals, in any quantity.
Many of them were first made when manufacturers had no legal requirement to carry out any safety tests, and none has been tested on humans. Add this to the fact that no-one knows which of these chemicals may react together, and things start to get scary.
In addition, the 77 chemicals tested are merely the tip of the iceberg. There are 100,000 synthetic, man-made ones in the environment, with 30,000 of those traded freely in the EU.
If a perfect test were available, it would probably prove I am home to hundreds, possibly thousands, of synthetic and toxic chemical compounds, the majority of which come under the umbrella of persistent bioaccumulative endocrine disrupters.
This means that they do not break down readily in the environment and therefore remain at large for many years once released, that they have the property of building up in living things in progressively greater quantities, and that they can interfere with the normal functioning of the hormone system of both humans and wildlife.
I contain 11 of the 42 PCBs tested for in the survey, although all at levels lower than the median of the volunteers. Considering that I was born after their manufacture was prohibited in 1970 and because of the very fact that they build up in the environment, I am rather alarmed by this.
However, according to Dr. Asma Khan, a London consultant hired by WWF to advise on test results, I
shouldn't be. Prior to being banned, PCBs were so ubiquitous you would be hard pushed to find anyone in industrial countries without detectable levels in their blood.
They are highest in animals high up the food chain, with the main dietary sources being fish (especially those caught in contaminated lakes or rivers), fish oils, meat and dairy products.
I am without doubt still being exposed to WWF's second target set of substances, organochlorine pesticides, which includes DDT, DDE, Lindane and HCBs. No matter how furiously I scrub my vegetables, I will be unable to erase chemical traces in certain food-stuffs, although I was found to contain only three of the 12 tested for, again all at lower levels than the group median.
Developed and in widespread use in the 1960s and used widely to control agricultural pests, as well as human and farm-animal diseases, many have now been banned in the UK after they were belatedly found to be highly persistent in the environment and cause long-term toxic effects in wildlife. Certain populations of birds of prey were devastated due to DDT causing their egg-shells to thin and break.
DDT from the mother can enter her unborn baby through the placenta. DDT has been found in amniotic fluid, human placentas,
fetuses and umbilical cord blood. DDT has been measured in human milk, so nursing infants are also exposed to it. In most cases, however, the benefits of breast-feeding outweigh any risks from exposure to DDT in the
Most worrying of all the tests was the exposure to flame-retardants, or polybrominated diphenyl ethers, PBDEs. These are used extensively in textiles and plastics, and are commonly employed in polyurethane foam for furniture and upholstery to mitigate domestic fire risk.
Having purchased a new sofa a year ago, I was not surprised to learn that this was the area where I was most contaminated. Although only five of the 23 tested for were found to be present, every one found was at concentrations significantly above the average.
There is a theory that these chemicals escape from materials and enter our bodies via our skin or lungs, so just by sitting on my new sofa, I am prolonging my contamination. Some scientists are also concerned that PBDEs may enter food from packaging.
The list of potential harmful effects is similar to that of PCBs, but less is known about them. Sadly, save for living in a Luddite world where all technological advances are outlawed, a PBDE-free existence will forever remain a fantasy.
I am not at all surprised that I am host to chemicals about which little is known of their consequences to human health. I am, however, angry that I have no freedom of choice in the matter.
Friday, 14th November 2003