Buried Hamilton airport chemicals could pose downstream health risk: federal study

A federal health risk study of buried chemicals leaching out of Hamilton's airport has revealed potential concerns" about eating downstream fish - or even some crops grown alongside area creeks.

The ongoing risk assessment began in 2015, a few years after scientists found high levels of perfluorooctane sulfonate (PFOS) in Lake Niapenco wildlife. Studies traced the now-banned pollutant, once used in firefighting foam, to a 1980s-era training pad at Hamilton's airport.

Despite efforts by the city's airport manager, Tradeport, to dig out and cap the training pad in 2019, Ontario's Ministry of Environment, Conservation and Parks said this week more work may be needed to prevent escaping pollutants.

The federal study is looking at the downstream impact of the chemicals along the Welland River from the airport as far as the eastern end of Lake Niapenco in Binbrook. The chemicals are thought to have travelled via ditches and creeks into the river.

A consultant has now mailed a study update to area residents outlining findings - including potential concerns" about long-term health risks of eating downstream fish as well as farmed beef or veggies in certain areas near creeks.

However, in an emailed response to Spectator questions, the federal government stressed the latest findings are based on conservative" assumptions and modelling - and therefore the risk may be overestimated."

That's why the next stage of the study will involve surveying area residents on the location of gardens, crops and cattle grazing in relation to creeks that could be polluted by the chemicals. Based on that information, the study team may test some crops, garden veggies or even milk from local dairy cows in the future.

For now, the government is not telling people to stop eating locally farmed veggies or beef.

As long as the grazing areas of cattle and the source area of local produce are not in close proximity to watercourses (like creek banks) the consumption of beef and produce ... is not likely to be of concern," the letter states.

Binbrook councillor Brenda Johnson said she was glad the long-sought health study had not been shelved," but also concerned she was not previously alerted to the findings - either as a councillor or board member with the Niagara Peninsula Conservation Authority.

I really hope they are going to engage with all the stakeholders," she said, noting the conservation authority manages Lake Niapenco, where some residents fish for food.

Scientists are still learning about the potential human health risks of PFOS and its wider family of chemicals, but some studies have pointed to potential impacts on natural hormones, the immune system and increased risk of some cancers.

The next stage of the survey will also survey well water use in the area. Johnson noted Hamilton public health did area testing as far back as 2012 and found no concerns in any well used for drinking water.

The federal study findings also suggest a greater risk for residents eating fish from the upper Welland River and Lake Niapenco, also known as the Binbrook reservoir.

The Ministry of Environment, Conservation and Parks already publishes fish consumption advisories that have taken into account PFOS contamination for years. But the federal study suggests further reducing the number of meals from fish caught in the study area.

For some fish in Lake Niapenco, including bass, catfish and crappie, the study findings recommend against any consumption at all by kids and women of child-bearing age."

The province has not yet specified whether it will update its public guidelines as a result of the federal study.

The Spectator has asked the conservation authority whether it will post warning signs at the popular Lake Niapenco reservoir, but a response was not available as of deadline Wednesday.

Matthew Van Dongen is a transportation and environment reporter at The Spectator. mvandongen@thespec.com