THanks for the links, Terry.
When I say "perceived increase in prevalence" I'm not talking about an increase in diagnosis, because we all know that autism is being diagosed a lot more these days. But ACTUAL prevalence in the past may have been no different, just that the past diagnostic parameters were far more strict and far less applied, than these days. You feel there has been an ACTUAL increase in prevalence to explain the increase in rate of diagnosis of autism, and this may be the case. Or it could simply be that more cases are actually getting seen to, as well as fewer of them falling through the cracks.
The accepted prevalence rate for autism in Australia varies depending on who you talk to, but the highest prevalence figures we are given for autism come from ASPECT (Autism Australia) who claim 1 in 100 with autism. More conservative estimates in Australia also claim 1 in 250.
From ASPECT's website - "Historically, the reported incidence of autism was 4:10,000. This has been revised over the past decade as we have better understood the range of Autism Spectrum Disorders. The most conservative estimate is now 27:10,000 (Fombonne, 2001) but most studies range from 62:10,000 (Chakrabarti & Fombonne, 2000) to 121:10,000 (Kadesjo, Gillberg & Hagberg, 1999) with a number of studies reporting rates in the 90's (91:10,000 Wolff, 1995 and 93:10,000: Ehlers & Gillberg, 1993). As a result, by using Wolff's study or Ehlers & Gillberg's study, the estimated number of people with Autism Spectrum Disorders in New South Wales alone is as high as 60,000, of whom 15,000 are children.
While there is agreement that there has been an increase in the incidence of autism, there is much debate about the possible cause(s) of this rise, with no clear conclusions to date. However, it is clear that assessment services are identifying more children at a younger age, especially those with High Functioning Autism (High-Functioning Autism (HFA)) and Asperger's Disorder."
What they are saying is what I was trying to say - that incidence may not have changed, we're just more likely to find it, recognise it and diagnose it (and hence those figures now become part of our current stats).
Depression, on the other hand, has a prevalence rate in Australia of 1 in 4 at any time in a person's life, 6% of the population in any 12 month period. So especially if you describe autism as a mental illness (which I don't, but some people especially our education departments do) than this pushes up the current incidence stats.
We need to be careful about describing current rates of diagnosis, as equivalent to incidence. Because yes, it IS getting diagnosed a lot more these days.
As for the health of our environment - again, I was speaking locally. Until very recently, all waste from our own property here stayed on site and was completely recycled. We have an extreme filtration system on our drinking water and we water our vegetable garden with rainwater. Where we live, our rainwater is very clean, since it comes in from the sea primarily and we are a long way from any industrial activity. Ours is the first dwelling built on this land, which is mostly sand. There has never been any industrial activity in this area. We grow our own poultry, feeding them from scraps and recycled matter. All animal feed is thoroughly scrutinised and regularly tested to make sure there are no additives.
However, I remember growing up on a farm and being told to keep away from this, stay away from that, go wash your hands after playing with the sheep because they got dipped last week, and so on. We would get slathered with strong pesticides before going out to play (Australia was the dumping ground for a lot of plant poisons and insecticides, long after the US banned them; we got a lot of war surplus post-Vietnam stuff). Our current neighbours used to routinely spray for termites, spiders and ants according to the calendar, ignoring important factors such as rain and wind. Or even whether there was a need. I strongly suspect the unofficial contractor he used was disposing of old, banned pesticides (organophosphates) through his spraying. This has stopped in the last 20 years, purely through lack of availability.
So I grew up in an environment full of chemicals, although they weren't used indiscriminately by my parents (unlike in some places). There were a lot of tight controls on agricultural use in our immediate area because we lived right next door to an agricultural wheat station and the professor who lived there was working primarily on natural methods of controlling pests, primarily breeding in resistance (especially to rust). So when we used chemicals likely to affect the what (such as when we dipped the sheep) we had to tell him what we used, when and how. So we were more aware than most, even though we still used stuff.
Hormones - my father worked for a groundbreaking chicken producer, the first and biggest in Australia. One of my brothers did too, both starting very early in the development of that business. There may have been hormone use early on, but if there were it was stopped by the early 60s because I remember a rather funny joke doing the rounds and I asked my father and my brother about how likely it was, and they said then, that there were no longer any hormones in the chicken feed (they'd probably shifted to antibiotics!).
For backyard producers like us, we would have cut costs by NOT including the hormones and antibiotics. The basic feed didn't have these additives, farmers wanting to use it had to add it (because my brother had the job of calculating for farmers, how much to add). I know it wasn't added at our home, because I helped feed the animals and I was often handling the animal feed for the range of animals we kept. We ate those animals, plus my mother was allergic to most antibiotics (as I am now) and my father wouldn't have risked her. My siblings handled the animal feed even more than I did, none of them are allergic as I am. I think I just inherited my mother's wonky and hypersensitive immune system. My mother certainly didn't get hers form the environment - she was diagnosed as asthmatic when very young (pre WWI), while she was still living on the land at a time when you got your own animals' feed.
It is a bit different in Australia. Sometimes we learn from other countries' mistakes before it happens here (as in thalidomide) and other times, chemicals get dumped onto our market. But generally we know about it, know when and where it's been used (Blue Mountains City Council were infamous for using Agent Orange) and know to avoid those areas.
So I am very aware, also aware that not everybody in Australia in the autism community (for example) agrees with me. I did some digging on the mercury in immunisations question, for example, and was assured from some very reputable sources that we haven't had mercury in Australian immunisations for many years. But an activist on our local committee assured me that mercury is still being used and that I was lied to. She produced a book to prove her point - then I noticed that she is one of the authors of that book. She also did not name her sources in the book, so it does make it difficult for me to accept her claim at face value. However, I am continuing to double-check rather than dismiss her claims out of hand.
One thing I have learnt to be VERY wary of - the automatic "they're lying to you" answer to any such query. Whenever I find a discrepancy in the information, or a claim that seems a bit too out in left field and my scepticism is met with, "But they're all lying to you, the conventional government bodies don't want you to know the truth, they're trying to shut us up, they're trying to discredit us," I have learnt, through my own independent thorough checking, that it's all hogwash, as a rule.
I have met people who made statements that seemed outlandish ("he lied to you all, I know because I was there and I saw him fudge his results") but I have seem them stand their ground and get vindicated. The truth will out, certainly on thie side of the ditch. We have too many ratbag journalists who won't be silenced! They love to pounce on claims such as "they're trying to poison us" and if there is any truth, we all know about it, fast (hence Blue Mountains City Council's purchase of Agent Orange, plus every subsequent use of it, was splashed across every morning newspaper until they depleted thier stocks of it).
So while I am keeping an open mind, I do not currently think chemical exposure was a causative factor in our particular family's incidence of Pervasive Developmental Disorder (PDD). As for testosterone - I have reason to KNOW that high levels of this hormone are also not a factor. Not for us.
I do believe that the causes of autism are likely to be multifactorial. ONe of difficult child 3's drama classmates has acquired autism, from a car accident when she was younger. I also have strong reason to believe that difficult child 3 was born as he is, there were signs in his first week that he was very different and I can look back and see signs of him stimming at a week old. Long before his first immunisation.
I will dig through your links, Terry. It may take me a few days, I have a house full of offpsring at the moment! I really want to concentrate on it all, and not keep getting pulled away from it.
Marg
