Average life expectancy is about the broadest indicator of a population's health that we have. In the simplest terms, it tells us if a given generation is doing better than the one that came before it.

In modern history, average life expectancies for most nations on Earth as well as for the human species as a whole have consistently trended up.

Thanks to improved hygiene, education, technology, and medical care, among other factors, each generation of humans lives longer than the previous.

And so, in the developed world, something has to be very wrong in a given region for its population's average life expectancy to begin to decline.

British Columbia is one area where that is happening, according to an October 23 report by Canada's chief public-health officer.

"On the whole, life expectancy has been steadily increasing in Canada over many years and it is comparable to other high income countries," the document reads. "Alarmingly, this is expected to change. For the first time in recent decades, life expectancy in British Columbia is decreasing, due to harms associated with opioid overdoses."

B.C.'s epidemic of drug-overdose deaths is now so severe that illicit narcotics are single-handedly responsible for dragging down the average life expectancy for the population of the entire province.

"Recent data from B.C. show that life expectancy dropped by 0.12 year from 2014 to 2016 due to deaths involving substances, with over 90% of these related to opioids," the report continues. "This dip in life expectancy was more pronounced in men and in poorer neighbourhoods."

The report notes that B.C.'s Indigenous populations are especially affected.

"Data from B.C. show that First Nations people are 5 times more likely to experience an opioid overdose event and 3 times more likely to die from an overdose than non-First Nations people," it reads.

There were 1,452 illicit-drug overdose deaths in B.C. in 2017, according to the province's coroners service. That compares to an average of 204 fatal overdoses recorded during the years 2001 to 2010.

In 2018, the rate of overdose deaths in B.C. per 100,000 residents stands at 30, miles above a rate of 7.3 overdose deaths recorded just five years earlier, in 2013.

The rate of fatal overdoses for the city of Vancouver stands at 56.1 per 100,000 people—an astronomical figure that is now nearly 10 times what the rate of overdoses was for Vancouver 10 years earlier (6.1 per 100,000 in 2008).

Today's report by Canada's top doctor, Theresa Tam, warns that the health catastrophe that B.C. has now struggled with for several years is spreading to other parts of the country.

"The opioid crisis is rapidly evolving across Canada," it reads. "While historically the greatest burden of opioid deaths has been observed in Western Canada, particularly in B.C. and Alberta, other parts of the country are also experiencing recent increases."

The report states that fentanyl, a dangerous synthetic-opioid that began contaminating B.C.'s supplies of illicit street drugs in 2011, is primarily to blame for Western Canada's overdose epidemic.

"Since then, there has been a sharp increase in both the number and percent of fentanyl-related deaths detected in the West, with more recent rises in jurisdictions like Ontario," the document reads. "In 2012, 4% and 11% of opioid overdose deaths in B.C. and AB were fentanyl-related; by 2017, this figure climbed to 84% and 79%, respectively."

Again, the problem is increasingly affecting other regions of Canada. Worse, the chief public-health officer warns that drugs even more dangerous than fentanyl have arrived.

"Close to 70% of opioid-related deaths in Ontario (2017) involved fentanyl, compared to 24% in 2012," the report continues. "Additionally, highly toxic synthetic opioids are becoming more pervasive. Carfentanil—100 times more toxic than fentanyl—has now been detected in overdose deaths in several provinces."

In response to sharp increases in drug-overdose deaths, top public-health officials working for the cities of Vancouver, Toronto, and Montreal, have argued that Canada's federal government should remove criminal penalties for the personal possession of drugs and address addiction issues as a health matter.

"Given the acute extent of the opioid crisis, some stakeholders, including people with lived and living experiences, have asked that the decriminalizing of additional psychoactive substances in Canada be considered," Tam's report notes.

Prime Minister Justin Trudeau and Canada's Liberal government has repeatedly said it the possibility of drug decriminalization will not happen while they remain in power in Ottawa.