More than a third (36%) of water points in public schools in Quebec have a lead content that does not meet Health Canada standards, according to data from the Ministry of Education. The method used by the ministry to detect the presence of lead in drinking water is however disputed by scientists who tested the measuring instruments acquired by Quebec, learned The duty.
The Ministry of Education released data on tests for lead in school water carried out in recent months on Friday afternoon. One-third (33%) of fountains or taps were non-compliant in 2,348 public primary schools. In the 845 secondary schools, this proportion reaches 43%. The average of non-compliant tests is thus 36% for all public schools.
Nearly a third of the fountains identified as problematic have been corrected, in particular by adding water filters, specified in the To have to Marc Sirois, Associate Deputy Minister at the Ministry of Education. The other water points deemed non-compliant have been closed until they are subject to work.
However, the validity of the tests is questioned by a new study examining the effectiveness of the device used to detect lead in school water. This instrument, the Palintest Kemio analyzer, was acquired without a tender at a cost of $ 1.7 million by the Ministry of Education in December 2019.
The Order of Chemists has always opposed the use of this portable device, which is considered less reliable than analyzes carried out in the laboratory with an ICP-MS type instrument, under the supervision of professionals.
To be sure, scientists from Quebec City decided to compare the two methods. They analyzed using the two types of instruments 1,490 water samples taken in 2020 in 240 municipal buildings. They compared the lead content in water revealed by the two methods.
Depending on what The duty learned, nearly 43% of the results obtained with the portable Kemio device are “significantly different” from those generated by the analyzes carried out in the laboratory; 22% of the measurements made by this portable instrument overestimated the presence of lead in the water, and 20% rather underestimated the content of this toxic metal.
Another fact considered to be worrying, 11% of the data obtained using the Kemio are considered “outliers”, because they are too far from the average of the results.
Caution
These data worry François Proulx, associate professor at the Drinking Water Research Chair at Laval University and scientific advisor to Quebec City. He is the co-author of this study on the reliability of Kemio. For him, the measurement of lead in water with this device used in schools “is not reliable”.
“That doesn’t mean that these devices shouldn’t be used. They must be used with discernment and precaution, ”explains the professor, who has more than 30 years of experience in the field of drinking water.
It recommends having all the tests carried out with the Kemio device validated in the laboratory, which conclude that there is no lead contamination in school water. There is a risk that these tests will be “false negatives” incorrectly concluding that the water is clean. “A false negative is the worst thing: we say that all is well and we close the file,” explains François Proulx, who is also a member of the board of directors of the Ordre des chimistes.
This professional order emphasizes that the Kemio device detects only lead dissolved in water. However, it is common for drinking water to be contaminated with lead particles detectable in the laboratory.
A contested decision
For this reason of reliability, the Ministry of Education has allowed school service centers to use engineering firms at their own expense to conduct their tests for lead in water. The Montreal School Service Center (CSSDM) has chosen this more reliable method. According to our information, the majority of service centers have opted for screening carried out using the portable Kemio device.
“The water points that have been declared compliant with the portable instrument, that does not reassure me. It doesn’t mean anything to me, ”says Michel Alsayegh, president of the Ordre des chimistes.
Quebec chose the Kemio device for very simple reasons, explains Professor Michèle Prévost, holder of the Industrial Chair in Drinking Water at Polytechnique Montreal: “We were looking for a device that would make it possible to take measurements quickly and inexpensively,” says she at To have to. […] The department has requested that this be done in less than a year. There wasn’t even a laboratory in the region to do that. Some labs were not accredited to measure below 10 [mg/l]. The minister was stuck and he moved quickly, I was happy. “
The professor chairs an expert committee to advise the Ministry of Education on testing for lead in water. It was she who recommended the acquisition of the Kemio. She recalls that The duty published in 2019 an in-depth investigation into the presence of lead in drinking water.
“The parents were very worried. There was pressure to do it quickly, ”she explains.
“Specialists’ debate”
Michèle Prévost deplores the attitude of the Order of Chemists, which acts out of corporatism in this file, according to her. The Order defends itself well. “They hate me, they are at war with me, it has become personal,” she says. They frighten parents unnecessarily. This is really not correct. “
Michèle Prévost recognizes that the Kemio device is less precise than the ICP-MS instrument used in the laboratory, but the important thing was to quickly detect the presence of lead in the water – and not the exact value – to condemn non-fountains. compliant, according to her.
This instrument is commonly used to measure lead in residential drinking water entrances, says the professor. The Associate Deputy Minister of the Ministry of Education, Marc Sirois, recalls for his part that the Center of Expertise in Environmental Analysis of Quebec determined at the beginning of 2020 that the Kemio device is adequate for screening. lead in water.
“It’s a debate between specialists between Ms. Prévost and the Ordre des chimistes. I am really referring to my committee of experts. I have confidence in Ms. Prévost, ”says Marc Sirois.