Banned DDT discovered in Canadian trout 70 years after use, research finds
Residues of the insecticide DDT have been found to persist at 'alarming rates' in trout even after 70 years, potentially posing a significant danger to humans and wildlife that eat the fish, research has found.
Dichlorodiphenyltrichloroethane, known as DDT, was used on forested land in New Brunswick, Canada, from 1952 to 1968. The researchers found traces of it remained in brook trout in some lakes, often at levels 10 times higher than the recommended safety threshold for wildlife.
'DDT is a probable carcinogen that we haven't used in 70 years here [Canada], yet it's abundant in fish and lake mud throughout much of the province at shockingly high levels,' said Josh Kurek, an associate professor in environmental change and aquatic biomonitoring at Mount Allison University in Canada and lead author of the research.
The research, published in the journal Plos One, discovered that DDT pollution covers about 50% of New Brunswick province. Brook trout is the most common wild fish caught in the region, and the research found DDT was present in its muscle tissue, in some cases 10 times above the recommended Canadian wildlife guidelines.
Researchers said DDT, which is classified by health authorities as a'probable carcinogen', can persist in lake mud for decades after treatment and that many lakes in New Brunswick retain such high levels of legacy DDT that the sediments are a key source of pollution in the food web.
'The public, especially vulnerable populations to contaminants such as women of reproductive age and children, need to be aware of exposure risk to legacy DDT through consumption of wild fish,' said Kurek.
Throughout the 1950s and 60s, half the province's conifer forests were sprayed with DDT, a synthetic insecticide used to control insects carrying diseases such as malaria and typhus. Canada banned the use of the substance in the 1980s.
The 2001 Stockholm convention on persistent organic pollutants banned DDT worldwide for mass agricultural use, although it is still permitted in small quantities for malaria control.
'This mess can't be cleaned up,' said Kurek. 'DDTs can persist in lake mud for decades to centuries and then cycle in the food web. The best approach is to manage the public's exposure of legacy DDTs by encouraging everyone to follow fish consumption guidelines and consider reducing exposure.
Sign up to Down to Earth
The planet's most important stories. Get all the week's environment news - the good, the bad and the essential
after newsletter promotion
'Our findings are a clear wake-up call to abandon our overreliance on synthetic chemicals. Lessons need to be learned so we don't repeat past mistakes. Our study hopefully informs on other contaminants that we apply broadly today, such as road salt and herbicides like glyphosate. We absolutely need to do things differently or our ecosystems will continue to face a lifetime of pollution.'
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Time Out
3 days ago
- Time Out
Montreal air quality among worst in the world today due to wildfire smoke, surpassing India and the Philippines
If you're finding it hard to breathe outside in Montreal today, it's with good reason. Smoke from the Canadian wildfires is causing poor air quality and reduced visibility in Montreal, and will carry through the weekend. A special air quality statement issued by Environment Canada warns that the smoke will lead to poor air quality and reduced visibility on Friday, and possibly Saturday. People are advised to limit time spent outdoors, and consider reducing or rescheduling outdoor sports, activities and events. According to the world air quality report, IQAir, Montreal is the second most polluted city in the world, ranking ahead of Delhi in India and Santiago, Chile. And while Toronto recently surpassed Montreal in the world's best cities list, Toronto ranked behind Montreal as the 4th most polluted city on the planet. What is causing the bad air quality in Montreal? Smoke from the wildfires in the Canadian Prairies is causing poor air quality and reduced visibility in the Greater Montreal region. What is the current air quality in Montreal? As of 11:30 a.m., Montreal's air quality index is at 168 and classified as unhealthy. What are the most polluted cities in the world right now? These are the world's 15 most polluted cities: 1. Tashkent, Uzbekistan 2. Montreal, Canada 3. Santiago, Chile 4. Toronto, Canada 5. Delhi , India 6. Detroit , USA 7. Medan , Indonesia 8. Kinshasa , Democratic Republic of the Congo 9. Dakar , Senegal 10. Chicago , USA 11. Batam , Indonesia 12. Lahore , Pakistan 13. Chengdu , China 14. Manila , Philippines 15. Chongqing , China What is the government's advice? Environment Canada warns that people most at risk from air pollution are seniors (65+), pregnant individuals, infants and young children, those with chronic health conditions, and people who work outdoors. As smoke levels rise, so do health risks. Outdoor activity should be limited and people should seek medical care if symptoms appear. Common symptoms may include eye, nose or throat irritation, mild cough, or headaches. More serious symptoms like wheezing, chest pain or severe coughing may occur. Keep windows and doors closed, but if extreme heat is also present, prioritize staying cool. To improve indoor air quality, use a certified portable air purifier or a high-quality air filter in your ventilation system. If outdoor exposure is unavoidable, wear a well-fitting NIOSH-certified N95 respirator or equivalent mask to reduce smoke inhalation. Note that even with a mask, some health risk remains. Finally, check in on vulnerable neighbours or loved ones who may need assistance.
Daily Mail
4 days ago
- Daily Mail
Nurse, 21, is unrecognisable after losing half her weight - she hails 'slimming' breakfast she ate every day for a year
A nurse who shed seven stone in a year without using weight loss medication has hailed the protein-heavy breakfast she ate every day as a key driver of her life-changing fat loss. Melanie Koz, 21, from Canada, lost almost half her weight last year, reaching a healthy 11 stone, and has showcased her incredible transformation in a TikTok video that's so far amassed more than 2million views. Her secret, she explained, was switching her carbohydrate-heavy diet of burgers, crisps and bread to an eating plan focused on low-fat proteins like diary and chicken. Key to this, she said in a series of social media videos, was the breakfast she ate 'every single day' for a year: a bowl of non-fat Greek yoghurt and honey topped with fruit. Not only did the meal keep her fuller for longer, protein helped her to 'build muscle' and become 'tighter and toned'. Her transformation, which began in 2023, came after years of failed attempts to lose weight, most of which involved a strenuous exercise routine, with little change to her diet. After leaving school and beginning her career as a nurse, she developed an unhealthy habit of eating cheeseburgers and bags of crisps as a coping mechanism after stressful shifts. But then, she enrolled on a nutrition course during her training, which dramatically changed her understanding of what constitutes a healthy diet. View this post on Instagram A post shared by mel (@ 'From there I used my newfound knowledge, and the rest is history,' she said. As well as her filling breakfasts, Ms Koz also overhaued the selection of snacks she'd use to get through a busy shift. Crisps and chocolate bars were ditched in favour of high-protein alternatives like edamame beans and cottage cheese. These nibbles are low in calories but 'fill your hunger', Ms Koz said in a video. 'Edamame is a great source of plant-based protein. It can help in building and maintaining muscle. It is [also] a great source of fibre which can help you feel full longer', she explained. Her meals, meanwhile, were classic favourites with a high-protein twist—like chilli with extra beans and homemade 'high protein pizza' with zero-fat yoghurt added to the dough, and low-fat cheese. She also spoke of eating puddings with a health twist, incorporating collagen and protein powder into a bowl of vanilla ice cream. Key to her weight loss, she said, was ensuring a calorie deficit—but it was easier to stay full with protein-heavy meals. View this post on Instagram A post shared by mel (@ What's more, this eating plan meant she didn't have to 'torture' herself with exercise. She simply invested in a home treadmill and went for long walks, before eventually joining a gym for some strength exercises. Now, she shares her simple weight loss hacks on social media in the hope of helping others who feel like they've hit a wall when it comes to transforming their health. 'I know how it feels to be on the other side of the screen wishing for a different body,' she said. 'I know the feeling of hopelessness after failing to lose weight countless times. For those reasons, I share my journey. 'I continue to hope that in some way, what I've shared and continue to share, has helped and will help at least one individual.' High protein diets have long been recommended by some health experts as an effective weight loss tool. This is thought to be because protein-heavy foods like meat and dairy take the body a while to process, keeping you fuller for longer and less likely to snack. Many high protein snacks are also lower in calories than those that are high in carbohydrates, like bread-based treats. Studies have previously found that high protein diets can aid weight loss by reducing appetite. Protein is a key nutrient that is crucial for building muscle, bone and skin. Currently the NHS and other international health bodies recommend eating roughly 0.75g of protein per kilogram of bodyweight every day.
Scotsman
5 days ago
- Scotsman
Why Israeli PM is wrong about UK. We just want Gaza's children to be fed
Sign up to our daily newsletter – Regular news stories and round-ups from around Scotland direct to your inbox Sign up Thank you for signing up! Did you know with a Digital Subscription to The Scotsman, you can get unlimited access to the website including our premium content, as well as benefiting from fewer ads, loyalty rewards and much more. Learn More Sorry, there seem to be some issues. Please try again later. Submitting... When the invitation arrived, my first thought surprised and frightened me, more than a little. 'Would I be safe if I accepted the invitation to the event at the Israeli Embassy.' It is not something that has ever crossed my mind about any of the events I have been invited to as an MP in the eight years since I was elected. But it was there, and very real. Advertisement Hide Ad Advertisement Hide Ad I felt the same anxiety a few days ago when I heard of the murder of Israeli Embassy staff in Washington DC. Is anyone now safe? It is not that this outrage was any worse or any more deplorable than what we are seeing in Gaza, or the Israeli people experienced on October 7. A girl holds a container at a food distribution point in the Nuseirat camp for refugees in central Gaza Strip (Picture: Eyad Baba) | AFP via Getty Images Retribution upon restribution It has long passed the point where sufficient adjectives are available to encapsulate the horror. But this latest murder somehow felt like a harbinger of even worse to come, that the conflict is now way beyond the control or even influence of the international community. And in the Middle East, it seems that retribution upon retribution is being sought with ever worsening tactics. Food is now a weapon of war. Humanitarian aid is being used as some sort of means of controlling people who have been left with nothing else but to fight for life. For 12 weeks, Israel blocked aid to Gaza and while our government, and indeed all political parties, recognise that country's right to defend itself against Hamas, the situation has now gone far beyond that. Advertisement Hide Ad Advertisement Hide Ad Last week the UK Government, together with France and Canada, warned that they were not prepared to 'stand by while the Netanyahu government pursues these egregious actions'. And that if the renewed military action and further expansion in the West Bank did not stop, they would 'not hesitate to take further action including targeted sanctions'. No place for Hamas There will be those who will say that it is too little, too late and that too many people have died, both Israelis and Palestinians. I know that I have felt that the pursuit of peace and the two-state solution which so many of us crave has been increasingly hopeless. And my frustrations that the Israeli government is not prepared to listen even to its own citizens who want an end to this war reached new heights with Netanyahu's reaction to that joint UK, French and Canadian statement. They had, he claimed, 'effectively said that they want Hamas to remain in power'. That is so far from the truth as to be nonsense. Every political party in this country, my own Liberal Democrats included, have made it abundantly clear that there can be no place for Hamas in the future of Gaza. Advertisement Hide Ad Advertisement Hide Ad We do want peace, for both the Palestinians and Israel. We also want an end to both the resultant Islamophobia and antisemitism which has reached previously unknown levels in this country. Perhaps more than anything else, I want to see the children of Gaza fed and the families of the hostages enjoy shabbat with their loved ones again.
