Originally published: July 26, 2015
Author: Sing Tao Daily
Status: Archived historical article
Last editorial review: October 2026

Criticism Over Illegal Disposal of Syringes; Sewage Flows Into Lake Ontario; Drinking Water Contains Drug Components; Experts: Boiling Won’t Eliminate Contaminants

[July 26, 2015]

[http://news.singtao.ca/toronto/2015-07-26/headline1437890980d5695694.html]

Sing Tao Daily Reporter

While the lead-contaminated water scandal in Hong Kong’s public housing estates continues to escalate, there are also concerns that drinking water quality in Ontario may be contaminated by medications and illicit drugs. McGill University released a report on water quality in southern Ontario, indicating that drinking water may contain substances such as cocaine and morphine.

Senior Certified Water Quality Expert Zhao Wenjie stated that the problem of water sources being contaminated by medications or illicit drugs is not a new phenomenon. This situation arises not only from the indiscriminate disposal of medications or syringes that are flushed into Lake Ontario but also—and primarily—because when people take medication, the human body actually absorbs only 25 to 30 percent of it, while the remaining 60% or more is excreted through the bloodstream and bodily waste, with these contaminants entering Lake Ontario via the sewer system.

He explained that Ontario’s wastewater treatment and filtration systems are designed to handle only bacteria in the water; sedimented drug residues cannot be filtered out by wastewater treatment plants, which is why the water quality study yielded these results. Zhao Wenjie also noted that it is not just the toxic substances mentioned in the report, such as morphine and cocaine, but also pharmaceutical contaminants in drinking water, including heart medications, antidepressants, and anticancer drugs, that are excreted by the human body and flow into Lake Ontario, eventually entering the drinking water supply after wastewater treatment.

Children absorb five times more than adults

When asked whether boiling drinking water would be effective to some extent in improving water quality, Zhao Wenjie candidly admitted that if the water source itself is contaminated with pharmaceuticals, boiling the water actually does little to help. Simply boiling water, as opposed to distilling it, causes high-quality water to evaporate during the process, while pharmaceutical residues and even harmful heavy metals in the water do not disappear as a result.

To minimize harmful substances in water, installing a water filtration system at home appears to be the only viable solution. Zhao Wenjie pointed out that, in addition to distillation, residents can also install a “membrane reverse osmosis filtration system” (Reverse Osmosis drinking system with Standard NSF58) at home. This system can filter out certain heavy metals and pharmaceutical residues. The entire system costs approximately 400 to 500 yuan, and users need to inspect and replace the filter system annually.

Although studies indicate that the levels of pharmaceuticals and illicit drugs in drinking water samples are insufficient to pose a serious health crisis, the possibility that daily drinking water may contain drug impurities remains a cause for concern for pregnant women and children. This is particularly true since children absorb five times more nutrients from their diet than adults, and a pregnant woman’s diet also affects the fetus. He recommends that households with children or pregnant women install a home drinking water filtration system.

He also noted that although the government has reminded the public to dispose of medications properly, some residents, seeking short-term convenience, still casually throw expired medications into trash cans or even flush them down the toilet—actions that undoubtedly exacerbate the problem of pharmaceutical contamination in water sources.

Regarding the lead-contaminated water scandal in Hong Kong, Zhao Wenjie does not believe that the government’s installation of water filters for affected households will completely resolve the issue. He explained that a water filtration system is not a one-time installation that eliminates future concerns; filter cartridges must be replaced annually, and the question of who will cover this expense requires further discussion.

2026 Editorial Update

This article was originally published in 2015 and is preserved as a historical record. Some of the language and conclusions, however, require context based on what we know today.

The article was based on research from McGill University that found traces of pharmaceutical and illicit-drug compounds, including cocaine and morphine, in the Grand River watershed in southern Ontario. The study also found that some compounds were not completely removed during water treatment.

Importantly, this did not mean that Ontario’s drinking water contained dangerous or intoxicating levels of drugs. The research focused on a specific watershed and trace concentrations, and the findings should not be generalized to all Ontario tap water.

Some statements in the original article were also too broad. Modern drinking-water treatment is not simply designed to remove bacteria; Canada uses a multi-barrier approach that includes source-water protection, treatment, distribution controls and monitoring.

The article’s recommendation that households with children or pregnant women install reverse-osmosis systems should also not be interpreted as current public-health advice. Reverse osmosis is one available treatment technology, but it is not something that every household requires.

Similarly, claims such as children absorbing “five times more” than adults, or people absorbing only 25–30% of medication, should be treated as statements made by the expert interviewed in 2015 rather than established facts.

One point from the original article remains relevant: medications should not be casually flushed down toilets or sinks. Ontario continues to encourage the proper return and disposal of unused medications.

In short

The underlying research was legitimate, but some of the original reporting presented the findings more broadly than the research supported. This page preserves the 2015 article while providing updated context so readers can distinguish the historical reporting from current understanding.