Canada's public health leaders took time out this week to do something they rarely do: celebrate success.
The annual conference of the Canadian Public Health Association was, in part, a 100th birthday party. It was an occasion to look at the triumphs of the past century, of which there are an astonishing number.
The CPHA published an e-book, This is Public Health: A Canadian History (available free at www.cpha100.ca) and produced a list of the 12 greatest public health achievements of the past 100 years.
The paradox of public health is that when it is effective it is invisible.
Virtually all the successes on the list are things we take for granted: the disease-sparing benefits of vaccination, food safety, safe childbirth, contraception and so on.
Yet each has had a profound effect on society and on our collective health. Since the CPHA was formed in 1910, life expectancy in Canada has climbed to over 80 from barely 50. To put it another way, every year a person was born after 1910 added four months to their life.
While medical care has improved dramatically, the vast majority of those gains are due to pretty simple public health measures.
A century ago, rates of child and maternal mortality were sickeningly high. The population was constantly stalked by outbreaks of disease. Unpasteurized milk, inadequately treated water and lack of sewage treatment killed. Many people risked their lives every day they went to work. Disability was a death sentence. Far too many Canadians were beaten down by poverty, particularly seniors. Prior to medicare, an illness could bankrupt a family.
To its credit, however, the Canadian Public Health Association did not simply look back, but cast its eyes to the challenges that lay ahead.
A century ago, the task was to build sewage systems and water treatment plants, massive infrastructure investments that have paid off in spades.
Today, the challenge is to move well beyond the dumping of feces and spread of microbes and to clean up the environment even more broadly.
Some of the most pressing issues for public health circa 2010 are to cap gushing oil wells (and reduce the damaging effects of fossil fuels generally), to put an end to massive deforestation and to slow (or reverse) global warming.
"In 100 years, when we look back, we will be judged by how well we adapted to our changing environment," David Butler-Jones, Canada's chief public health officer, told delegates.
The environment has become one of the primary concerns of public health in the 21st century: not only the natural environment, but the built environment too.
The fact that 90 per cent of the population now lives in cities has a tremendous impact on health and that should be reflected in public health priorities.
So too should the modern workplace. While workplaces are much safer today than they were in 1910, it is debatable whether they are actually healthier. Chemicals are not the sole source of toxicity: Overwork can be deadly, and loss of work-life balance broadly damaging.
While infectious diseases do a lot less damage than they used to - at least in wealthy countries like Canada - there are always new ones, from HIV-AIDS to SARS to H1N1.
And immunization, despite its astounding benefits, remains a tough sell. A century ago, anti-vaccinationists torched the house of Canada's Chief Vaccinator; today, they do their damage online by spreading falsehoods and sowing fear.
This serves as a reminder that: 1) progress cannot be taken for granted and; 2) effective communication remains primary for successful public health initiatives.
While public health gets a tiny fraction of health dollars - about 4per cent of spending goes to prevention and health promotion and 96 per cent to sickness care - it has always batted well above its weight.
Public health has always been a voice for the underdog. That is why, during the CPHA conference, much of the discussion was dominated by talk of social determinants of health.
The reality is that the economic and social conditions in which we live - income, housing, education, physical environment and support networks - ultimately have more impact on our health than genetics or lifestyle choices.
The most socially and economically disadvantaged in society have the worst health outcomes - and in Canada that means aboriginal people, immigrants, people with mental and physical disabilities and, to a lesser extent, women.
In Canada, social programs have been used to correct some of those imbalances, one of the principal reasons we have good health outcomes. But in recent years there has been a sharp decline in income-redistribution programs; social assistance has become a dirty word.
Among aboriginal people on reserves, in particular, health circumstances and outcomes are shockingly similar to 1910. It has been a lost century of public health advances for First Nations.
One of the priorities for public health has to be to tackle this national shame. There has been recognition, but now action is required. Doing so will require promoting civic engagement and social solidarity, to create (or recreate) a society in which it's not okay to not care.
After all, as a country, we are only as healthy as the least healthy among us.