Pages

Total Pageviews

Saturday, May 30, 2015

Ecological Determinants of Health

A Working Group of the Canadian Public Health Association led by Dr Trevor Hancock has been deliberating on the implications of the environmental and ecological trends that are apparent to all of us. These trends have consequences for public and population health, indeed for everyone's personal health.  The Working Group has produced a Discussion Paper, available at http://www.cpha.ca/uploads/policy/edh-discussion_e.pdf.  It is a brief, clearly written document, setting out the most obvious trends: climate change, stratospheric ozone depletion and increased ultraviolet radiation, resource depletion, especially fresh water for drinking and irrigation, environmental pollution, species extinction, reduced biodiversity, desertification. For more than 30 years beginning in the early 1980s I wrote and spoke a great deal on this cluster of trends and changes in our world and its life-supporting ecosystems. I chaired a study  group of the Royal Society of Canada and an international workshop convened under the auspices of Health Canada, and was a special adviser to the World Health Organization. Occasionally I was an official Government of Canada reviewer of scientific reports of the United Nations' Intergovernmental Panel on Climate Change (IPCC). A chapter on "Human health in a changing world" was the centre-piece of the 2nd edition of my book Public Health and Human Ecology (1997). Colin Soskolne at the University of Alberta helped me to expand and update this as Chapter 52, pp 925-937 in the 15th edition of the massive reference textbook Maxcy-Rosenau-Last Public Health and Preventive Medicine (2007).  

The fire in my belly is beginning to subside into glowing embers and my expertise on these important topics is becoming dated and no longer carries much weight. Accordingly I was especially pleased to read Trevor Hancock's report. It is required reading for all thoughtful Canadians, especially those who care about the world we will leave to our descendants. Among much else, Trevor Hancock's report has political implications. Nobody who heeds its message could ever vote for a political party that regards life supporting ecosystems as irrelevant, or considers sustaining them to be an impediment to economic growth and business as usual. In the fire-eating mood that sometimes overtakes me, I regard political parties with that view of the world as enemies of life on earth. It's incomprehensible to me that such political parties attract support, let alone enough support to win elections as they often do in the USA and did in Canada last time. I would as soon take a dose of cyanide as vote for any candidate of such a party. Alluding to that sort of weltanschauungin 1991 I entitled an article in World Health Forum "Homo sapiens - a suicidal species?" That message, and that article were well received by readers around the world.

There is often an omission from the litany of dangerous factors threatening the survival of the world as we know it. Many writers avoid any discussion of population growth and population pressure on fragile environments and ecosystems, or if they mention it, they pussyfoot around the edges, seemingly afraid of arousing the wrath of those who uphold what are often called "family values."  Publishers' editors discouraged me in the 1980s when I wanted to discuss in depth the harsh reality that the population exceeded the earth's carrying capacity by at least an order of magnitude. Our present numbers, about 7.4 billion, are unsustainable. The world would be a more comfortable place to live, more peaceful withal, and a happier place for everyone, if instead of 7.4 billion of us, there were 740 million (or perhaps as few as 74 million, two orders of magnitude fewer).  I have been concerned about population pressure since my medical student days in the 1940s.  My very first professional publication, in 1949 a few months before I graduated from medical school, included a brief discussion of population and my concerns about the rate at which the world's population was increasing. At that time it was rising by about 10 million/year, trivial compared to the present annual increase of more than 70 million. 

As I recall those times just after the end of the 1939-45 world war, I think of the clean air, the pristine beaches, the sparkling clear seas around the South Australian coast, the abundant fish in the sea, the thriving bird and insect life of the Australian bush. How everything has changed!  Although parts of the world were scarred by the destruction of the 1939-45 war, it was a golden age environmentally speaking. The environmental and ecological deterioration that is so obvious now even to a casual observer such as me, had not begun in those immediate postwar years. The concept of global climate change hadn't even been imagined, and nor had any of the other global ecological and environmental changes that threaten all life on earth. I remember a night in, I think, 1948, when I was 22 years old. Petrol rationing had ended; On a limpid warm evening I had driven into the Adelaide hills with my girl friend of the time, determined to lose my virginity. I didn't succeed in that aim, but many my age did around then. The consequence was the Baby Boom. It began with a bang, a hyper-exponential population surge that very soon overloaded the world with more people than it could comfortably hold. The hyper-exponential surge has subsided but the increased numbers in the fertile years gave fertility rates enough momentum to maintain the unsustainable population growth rate.  Vastly greater numbers now than a generation ago in China, India, Brazil, Indonesia, are affluent enough to afford automobiles to take their girl friends, their families, from cities to the countryside, and to use their cars to commute, rather than use public transit systems. Every one of them adds a moiety to the global burden of greenhouse gases that are changing the world's climate irrevocably. It's no wonder that polar and alpine ice caps are disappearing, glaciers are receding, sea levels are rising. At the same time pesticides intended to enhance agricultural production are exterminating insects including bees that are essential for pollinating many crops.  Artificial fertilizers are causing huge dead zones around pelagic run-off regions from all the world's large rivers, monoculture - genetically homogenous - crops are reducing biodiversity; industrialized fishing methods are destroying fish stocks. And underlying it all, worst of all, the increased atmospheric burden of carbon dioxide from combusted carbon fuels is not only changing the climate inexorably, it is acidifying the world's oceans and lakes; and this is disrupting ecosystems and reproductive cycles, with consequences not much less dangerous than the global temperature rise that is now an absolute certainty. The world of my childhood and youth is lost to us forever. 

Trevor Hancock's report is more positive than my gloomy prognostications, so read that rather than this blog post. I'll try to be more cheerful next time.    


Sunday, May 24, 2015

Thinking in Pictures

Nosology is a domain of scholarly activity in which I've trodden from time to time. The word doesn't mean the scientific study of noses, as one of my friends derisively remarked years ago after a learned article on the subject was published under my name. Nosology is the systematic classification of diagnostic labels. This is a necessary prerequisite if we are to think constructively, rationally and critically about diseases, injuries, disabilities, causes of death, and especially about causes of mental, emotional and personality disorders. The Diagnostic and Statistical Manual of Mental Disorders is an attempt to create an authoritative classification or nosology of the ill-defined, often murky world of disturbances that can afflict the mind.  Its fifth edition, DSM5 for short, has been the latest word on nosology of mental disorders since 2013. Like its predecessors DSM5 has been heavily criticized.  The most cogent criticism is that it attempts once again to define the boundary between 'normal' and 'abnormal' human behaviour. It draws a sharp line where the reality is an extremely vague and fuzzy blur. Nowhere is this truer than in its discussion of autism.

DSM5 provides a lengthy description of symptoms and signs of autism, emphasizing deficits in social communication and interaction, and restricted range of behaviour,  interests and activities. By DSM5 criteria, appreciable numbers of epidemiologists and medical statisticians are autistic.  When I was compiling the first edition of the Dictionary of Epidemiology, I presided over a fascinating scholarly exchange of views about the definition of several important basic terms all epidemiologists must understand and agree upon.  One of these scholars thought about and defined these terms in words and concepts; the other scholar defined the same terms in mathematical formulae. This was an example of two fundamentally different thought processes, both equally valid.* One is the customary way most of us think, i.e in words and concepts; the other is comparable to Temple Grandin's description of the way she thinks: in pictures. Perhaps the experts who compiled DSM5 should have consulted Temple Grandin. She is a renowned veterinary scientist who has exceptional empathy with animals. Her best known achievement is the design of humane slaughter houses in which sheep and cattle proceed placidly along a curved ramp and cannot see the fate that is in store for them. Her designs are now used by over half the slaughter houses in the USA and many in other countries.


By the accepted criteria of DSM5 - and her own criteria - Temple Grandin is autistic. She has exceptional capacity for introspection and analysis of her own thought processes. She says that while most of us think in words, she thinks in pictures. Her analysis is probably correct. I'm sure some people do think in pictures, or in symbols or concepts. But Temple Grandin can think, or at any rate can write, in words too. Her memoir, Thinking in Pictures, is a clearly written account of some aspects of her life and work, notably an insightful account of how she adapted to her autism, her adaptation to her physical need to be constrained when she wants to relax or sleep.  She invented and built a device she calls her 'squeeze machine' which tightly embraces her body, providing a substitute for the hugs of loved ones that she can't tolerate. Like many autistic people, she can't tolerate intimate interaction with other people.  In a moving clinical essay about her, published in his collection called An Anthropologist on Mars, Oliver Sacks implies that he may be an exception in that he does seem to have established rather intimate interaction at any rate with her thoughts and emotions; Temple Grandin's account of their relationship, and a photograph reproduced in Thinking in Pictures, reinforce my impression that he and Temple Grandin did achieve a degree of emotional interaction that is highly unusual in autism. But then Oliver Sacks is not only a physician, a clinician who first encountered Temple Grandin in a doctor-patient relationship, he is also a man of exceptional empathy and charisma, despite his assertion that he is a very shy man. Temple Grandin describes how using her 'squeeze machine' enabled her to relax, and to interact more effectively with animals - to think as animals do, to acquire empathy for them. That is perhaps a large part of the reason why she is such a brilliant veterinary scientist, particularly in the field of behaviour and emotions of animals.

Oliver Sacks and Temple Grandin are each in their own way demonstrations of the difficulty, indeed the futility, of attempts to establish a workable nosology of mental disorders, in which diagnostic labels are, so to say, carved in stone. The problem arises with that word 'disorder' - what is a disorder, and what is an unusual variation of normal that makes a person exceptional in the highly desirable way that Temple Grandin and Oliver Sacks are both exceptional?   I doubt if we will ever satisfactorily answer this question.  

* This exchange of ideas in letters to me from these two eminent epidemiologists is now among my collected papers and correspondence held in the National Archives of Canada.

Sunday, May 17, 2015

Can't we talk about something more pleasant?


Roz Chast has been a frequent cartoonist in the New Yorker for many years. Her cartoons, usually a page, resemble the panels of a comic strip, and tell a story. Her humour, while not quite black, often comes in assorted shades of grey.  Now she has drawn and written a memoir of the last years of her parents, George and Elizabeth Chast, a devoted couple of retired school teachers who had been married for 67 years. They were offspring of Jewish immigrants who came to the USA from Russia at the cusp of the 19th-20th century. They were an inseparable couple, parted only during the war which for them lasted from 1941 to 1945. George spent much of the war in New Guinea; during that period of separation, he and Elizabeth wrote to each other almost every day.

This book is mostly humorous in shades of grey that sometimes descend into the blackest of black and are not so much funny as heart-breaking.  It is a memoir of the slow decline of an elderly and fiercely independent couple into senescence, dependency, loss of autonomy, loss of mind, loss of control of bodily functions, and it is a sobering message to all of us about the tragic, unspeakably unpleasant fate that awaits us if we postpone death for too long. Like many old people, they were in denial about their increasing need for help. There are lessons for all who have to care for aged kin who have lived on long past their "Best Before..." dates. Long-term care of the very old is a labour-intensive business, a 24/7 business that is very hard on the care-giving kin, taking over their lives, sometimes tearing them apart from their own spouses and children. Roz Chast doesn't say anything about this even by hints or inference but it must have been hard on her husband and teen-age daughter. Long term care is a business that generates big profits for the owners of nursing homes and assisted living establishments,  and for the pharmaceutical and surgical supply corporations. It can pauperize the dependent elderly, in extreme cases can pauperize their next of kin too.  Roz Chast does describe in searing detail how costly it all is. Fortunately her parents had good pensions, but the vitally important features of their health insurance coverage were valid only in New York, and ceased when Roz Chast had to move them from their cluttered apartment in Brooklyn to an assisted care residence nearer to her home in Connecticut. The book reproduces Roz Chast's hand-written accounts  of the major crises on her parents' lives, illustrating these not only with cartoon panels but also with photos of her parents' tiny, cramped apartment, the unworkable mess of piled heaps of papers on their "work stations," her father's old electric shavers, her mother's old blenders.

There are sobering lessons here for all old people, and for all who are growing old, becoming less autonomous, more dependent upon others for help, then ultimately for mere survival.  There are lessons for me! My father and grandfather lived to advanced old age, until they became blind, bedridden, lost control of bladder and bowel, lost all autonomy: after lifetimes of independence that in my father's case was fierce to the point of savagery, they became utterly dependent upon others in order to survive.  My father was infantilized, washed, fed, diapered like a baby, a fate that he must have felt almost worse than death, although he was too proud ever to say so. Above all else I want to avoid that fate! I hope by the time I need it, assisted suicide will be legally permissible in Canada.

Few of us get our preference about how we will die.* Advance directives and legally sanctioned assisted suicide (if Parliament decrees this) can help us old farts get our wish - everyone’s wish - for a tidy, stress-free end of life. Unfortunately the harsh epidemiological reality is that increasing numbers languish for years, even decades, in warehouses for the partially dead that we euphemistically call nursing homes. Aging baby boomers could exercise political clout that might lead to enabling legislation, but many are like Roz Chast’s parents: in denial. I’m closing in on my 89th birthday and somewhat in denial although I can still fend for myself, do my own shopping, bathing, dressing. I have help with cleaning and cooking. When/if the need arises I’ll squander my kids’ inheritance to pay for personal care worker, home nursing care: stay home and evade warehouse demi-living. When push comes to shove, however, I’ll probably shy away from assisted suicide because like my father before me I’m intensely curious about the world, and about my progeny’s lives and what they will do next.  

* My preference is to be shot in the back by a jealous husband on my 98th birthday. I’m sure I won’t get that wish!

Sunday, May 10, 2015

The Guardian's campaign on climate change

The CBC Sunday Edition's feature today on the UK/global newspaper The Guardian pulled a few punches, but still made the point: climate change is the greatest threat to life on earth since the cataclysm 65 million years ago that wiped out the dinosaurs. The Guardian is continuing a long tradition of campaigning newspapers. My homeland, Australia, and my adopted country, Canada, both depend on fossil fuel extraction for much of their wealth. But The Guardian is right, political leaders in Canada, Australia, and many other countries that have become wealthy and influential because they extract and/or use prodigious quantities of carbon fuels, are wrong, dead wrong, to believe and eagerly disseminate the lies, half-truths, misinformation and obfuscation of carbon fuel advocates. For my grandchildren's sakes, and for the sake of all who come after them, may truth and the good guys prevail! The Guardian's call for society's opinion leaders to divest from the fossil fuel industry is a sound strategy. It might work if the boards of the Bill and Melinda Gates Foundation, the Wellcome Foundation, and others took up the challenge.

The first punch pulled in this morning's CBC feature was to say that "90%" of scientists support the scientific evidence. The truth is nearer 99%. The media's near-universal obsession with "balance" leads them into the trap set by the carbon fuel advocates and their tame "scientists," lobbyists and shills. It is a reprise of the artificial "debate" in the 1960s about smoking and lung cancer. In reality there is no "debate" - all the facts, all the evidence, confirm the reality of climate change. The hard facts can't be refuted. For instance, 14 of the 15 hottest years ever recorded have been in this century, which is only 15 years old. The relentless retreat of polar and alpine glaciers and ice-fields is further irrefutable empirical evidence. The underlying science has been known and studied for well over 100 years. Almost all of the so-called "scientists" recruited by industry or drawn into debates and discussions for other reasons are either pronouncing on scientific evidence outside their domain of expertise, like Freeman Dyson, bloody-mindedly obstinate, or have been bought, body mind and soul, by the carbon fuel industry, which has virtually unlimited wealth and has obvious reasons to promote its own interests.   

Of course other global changes are occurring. In an article I wrote for the Annual Review of Public Health in 1993, I focused on stratospheric ozone depletion and its far-reaching biological consequences. Even the right-wing ideologue Margaret Thatcher, UK prime minister, was persuaded by this evidence, and was an eloquent advocate for the Montreal Protocol (1987) to limit production and use of ozone-destroying substances. In the same review article I summarized the evidence on greenhouse gas accumulation and its horrendous impact. In the 22 years since then, climate change has become the dominant threat, but the harmful biological effects of increased ultraviolet radiation remain menacing even though they have been partially contained by controlling production and use of many ozone-destroying substances. 

Other global changes - resource depletion, especially of fresh water for drinking and irrigation, species extinction, emerging pathogens, reduced biodiversity, population pressure, unprecedented migrations, industrial development, environmental pollution and desertification, have been synergistic with climate change, but climate change is the most dangerous. Its immediate effects have been increasingly apparent in recent years and are becoming more serious much sooner than the theoretical models were predicting 35 years ago when I first became seriously engaged with the implications of climate change for public and population health. Changes that the theoretical models predicted for late in the 21st century or even further off, are already happening. It is increasingly likely that ice-melt in Greenland and Antarctica that was predicted by the models to be several hundred years away - plenty of time to prevent by aggressive mitigation initiatives - will happen before the end of this century, in the lifetime of my grandchildren. This will cause a sea level rise of 5-7 meters, that will inundate Amsterdam, London, New York, Miami, Washington-Baltimore, Lagos, Kolkata, Shanghai, Tokyo, Rio de Janeiro and many other large cities located at or near sea level. More than half a billion people live within a meter of current sea levels. Well over a billion will lose their habitat when the Greenland and Antarctic glaciers and ice-fields melt.  Desertification is rapidly advancing too.  California is becoming a desert because shifting Pacific ocean currents are causing a drastic decline in precipitation, rainfall and snow on the coastal mountains. This is a longterm climate change, not a consequence of capricious weather in recent years. Ocean currents are changing direction and force because ocean temperatures are rising. California's carrying capacity is at the beginning of a longterm, irreversible decline. Where will all the parched Californians go? There are many more than there were Oklahomans who moved to California in the dust-bowl 1930s.    

Perhaps these trends presage a major evolutionary upheaval, the end of the dominance of homo sapiens  and the rise of arthropods - beetles, cockroaches and ants - that are more tolerant of deserts and heat, more efficient converters of energy from their food intake, than hot-blooded humans.

Tuesday, May 5, 2015

The craft and art of Oliver Sacks

Oliver Sacks is dying of malignant melanoma with metastases in his liver. He described his predicament in a lyrical Op-Ed essay in the New York Times in February 2015.  He is English by birth and education. After graduating in medicine from Oxford and the Middlesex Hospital Medical School in London and the obligatory internship in the UK, he set off for North America, footloose and fancy free for a while, living a roving, restless life with which I strongly identify. He came to rest eventually in San Francisco where he gravitated into neurology. This proved to be his intellectual and spiritual home. He continued exploring this calling after he moved across the continent to New York where he came to rest more or less permanently, associated initially with Beth Abraham, a chronic neurological hospital affiliated with Albert Einstein College of Medicine in the Bronx. I think it was during this period that I first met him, in the early 1970s during a site visit for the NIH Epidemiology and Disease Control Study Section. It was a transient meeting, as was another a few years later during my sabbatical year at Mount Sinai Medical College. Like Oliver Sacks, I have poor facial recognition ability: all I can recollect is a large man with great charisma (not enough, however, to persuade the hard-nosed Study Section to award high priority to an application for research funds).  By then his award-winning book, Awakenings, had been published in the UK but perhaps not yet in USA and he had not yet established his reputation as the greatest medical writer of his time. Awakenings is about the dramatic improvement of vegetable-like victims of post-encephalitic Parkinson's disease when given l-dopa; it was later made into a very good movie starring Robin Williams as Oliver Sacks. I have read every one of Oliver Sacks's books - mostly personal accounts of patients with bizarre neurological or neuropsychiatric aberrations. Most have been best sellers and several, e.g. The Man Who Mistook His Wife for a Hat and his essays on the autistic savant Temple Grandin (An Anthropologist on Mars) who transformed slaughterhouse practice in USA, have passed into our culture. I think Oliver Sacks would be a more worthy candidate for the Nobel Prize in literature than some recent recipients. Not only is he a master of English prose; he is a great humanist, with profound understanding and insight into the human condition.

Now I am reading his final book, a memoir, On the Move. He writes more openly than hitherto about his homosexuality, and describes frankly and objectively his adventures and misadventures with illicit drugs. His accounts of weekend high speed travels on his motor-bike from Los Angeles to the Grand Canyon and back almost make my flesh creep. I hardly know him, but regard him as an old friend because I know him so well through his brilliant essays. I am very glad he was spared an untimely death despite his self-destructive behaviour.