logo
Banned DDT discovered in Canadian trout 70 years after use, research finds

Banned DDT discovered in Canadian trout 70 years after use, research finds

The Guardian21-04-2025

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.'

Orange background

Try Our AI Features

Explore what Daily8 AI can do for you:

Comments

No comments yet...

Related Articles

The six dog breeds most likely to get DIARRHOEA revealed by scientists – and why Jack Russells evade dreaded ‘poonami'
The six dog breeds most likely to get DIARRHOEA revealed by scientists – and why Jack Russells evade dreaded ‘poonami'

Scottish Sun

time4 hours ago

  • Scottish Sun

The six dog breeds most likely to get DIARRHOEA revealed by scientists – and why Jack Russells evade dreaded ‘poonami'

There may even be a "genetic element to the condition," the study said COCKA-POO! The six dog breeds most likely to get DIARRHOEA revealed by scientists – and why Jack Russells evade dreaded 'poonami' SCIENTISTS have revealed the six dog breeds most likely to suffer from diarrhoea. It turns out some pups are unfortunately more susceptible than others. Advertisement 5 A Cockapoo, sometimes called a Spoodle or Cockadoodle, is a cross between a Cocker Spaniel and a Poodle Credit: Getty 5 Maltese pups are one of the dogs believed to be more susceptible to diarrhoea Credit: Getty 5 According to researchers, the Jack Russell Terrier and Chihuahua are less likely to experience the messy condition Credit: Getty Roughly one in every 12 dogs in the UK will be diagnosed with diarrhoea each year, according to a new study. The study, published today in the journal PLOS One, revealed that the following dog breeds are most at risk of a "dreaded poonami": Maltese Miniature Poodle Cavapoo German Shepherd Yorkshire Terrier Cockapoo There may even be a "genetic element to the condition," the study said. That means there's something within the genes of these six breeds that makes them more likely to get diarrhoea than others. Advertisement With a pool of about 2.25million dogs, lead author Dan O'Neill, of the Royal Veterinary College, UK, and his colleagues, discovered that there were two breed least likely to suffer. According to researchers, the Jack Russell Terrier and Chihuahua are less likely to experience the messy condition. The researchers note that it is the diets and exercise habits of different breeds may influence this. The study relied on data from vets around the country. Advertisement So the researchers added that the different likelihoods of owners taking their dog to the vet in the first place could have skewed the results. Dogs prefer EVs to fuel-powered cars with heart rates revealing exactly how your pet feels on drive, study shows The condition is most common in dogs under three years old or older than nine years, the study said. Young pups that often eat things they shouldn't may also have digestive issues, while older dogs may experience it as a complication of ageing. More than 80 per cent of suffering pups get better after one trip to the vets, the researchers also found, suggesting the condition is short-lived. Advertisement 'Experiencing the dreaded 'poonami' with your dog is one of those events any dog owner fears," Dr. O'Neill said in a statement. "This new study shows that diarrhoea events are very common in dogs but that owners should not panic. "No matter how bad the deluge, most dogs will recover in a few days after veterinary treatment.' 5 Miniature or Toy poodles are also common sufferers Credit: Getty Advertisement

The six dog breeds most likely to get DIARRHOEA revealed by scientists – and why Jack Russells evade dreaded ‘poonami'
The six dog breeds most likely to get DIARRHOEA revealed by scientists – and why Jack Russells evade dreaded ‘poonami'

The Sun

time4 hours ago

  • The Sun

The six dog breeds most likely to get DIARRHOEA revealed by scientists – and why Jack Russells evade dreaded ‘poonami'

COCKA-POO! There may even be a "genetic element to the condition," the study said SCIENTISTS have revealed the six dog breeds most likely to suffer from diarrhoea. It turns out some pups are unfortunately more susceptible than others. 5 5 5 Roughly one in every 12 dogs in the UK will be diagnosed with diarrhoea each year, according to a new study. The study, published today in the journal PLOS One, revealed that the following dog breeds are most at risk of a "dreaded poonami": Maltese Miniature Poodle Cavapoo German Shepherd Yorkshire Terrier Cockapoo There may even be a "genetic element to the condition," the study said. That means there's something within the genes of these six breeds that makes them more likely to get diarrhoea than others. With a pool of about 2.25million dogs, lead author Dan O'Neill, of the Royal Veterinary College, UK, and his colleagues, discovered that there were two breed least likely to suffer. According to researchers, the Jack Russell Terrier and Chihuahua are less likely to experience the messy condition. The researchers note that it is the diets and exercise habits of different breeds may influence this. The study relied on data from vets around the country. So the researchers added that the different likelihoods of owners taking their dog to the vet in the first place could have skewed the results. Dogs prefer EVs to fuel-powered cars with heart rates revealing exactly how your pet feels on drive, study shows The condition is most common in dogs under three years old or older than nine years, the study said. Young pups that often eat things they shouldn't may also have digestive issues, while older dogs may experience it as a complication of ageing. More than 80 per cent of suffering pups get better after one trip to the vets, the researchers also found, suggesting the condition is short-lived. 'Experiencing the dreaded 'poonami' with your dog is one of those events any dog owner fears," Dr. O'Neill said in a statement. "This new study shows that diarrhoea events are very common in dogs but that owners should not panic. "No matter how bad the deluge, most dogs will recover in a few days after veterinary treatment.' 5 5

Woman who travelled to 7 countries last year follows key rules to avoid sickness
Woman who travelled to 7 countries last year follows key rules to avoid sickness

Daily Mirror

time10 hours ago

  • Daily Mirror

Woman who travelled to 7 countries last year follows key rules to avoid sickness

Everyone falls ill sometimes but no one wants to feel sick on holiday, so a woman who travelled to seven countries last year has shared some tips for travellers who want to stay in good health during their trip A Canadian woman who travelled to seven countries last year has taken to TikTok to share her secrets for staying illness-free on holiday. There's nothing worse than falling ill while on a much-anticipated getaway, particularly when you've been pining for that relaxing break. While most holiday-goers think about packing outfits and important travel documents, not everyone considers taking steps to avoid falling ill abroad. Sadaf, a content creator who focuses on fashion, food, and travel, shared a video recently with some health tips for those aiming to dodge sickness during their travels. She said: "Last year I travelled to seven countries and 14 cities and I never got sick once. This is what I do to make sure I don't get sick on vacation. ‌ "I don't know about you but getting sick on vacation literally feels like I'm burning money. [I] just spent so much time, effort, money, vacation days to be here and now I'm sick and have to spend my whole day in a hotel room? ‌ "These are the simple but effective things I do to make sure that I don't get sick on vacation." 1. Wear a mask on the flight First on Sadaf's list of preventive measures is wearing a mask during flights. She strongly advises fellow jet-setters to wear masks in the air, believing close spaces and breathing recycled air within a plane mean you're "bound to catch something". The travel fan recommends wearing a mask for the return flight as well, to ward off any potential bugs from fellow passengers who might have fallen ill during their travels. In an interview with Travel + Leisure, Dr. John Dooley, MD, shared his thoughts on the topic, stating that while he doesn't typically urge healthy people to wear masks on planes, he's not against it if it reduces the risk of catching a respiratory infection. He remarked: "I don't routinely recommend people wear masks on airplanes, but I have no objection whatsoever if it helps to lessen one's likelihood of picking up a respiratory infection." ‌ Dr. Dooley also pointed out that if someone on your plane is unwell and coughing, there's a "not insignificant chance" they could pass their illness to others near them, so wearing a mask could offer some reassurance. 2. Disinfect your phone Sadaf emphasised: "Number two is simple but making sure that at the end of the day on a trip you're wiping down and disinfecting your phone." ‌ She explained that after a day out, most travellers would shower, slip into clean pyjamas, and snuggle into fresh bed linen, only to then handle their phones without considering how many germs have accumulated on their phone that day. To combat this, Sadaf makes it a habit to cleanse her phone with a disinfectant wipe or, if she doesn't have any, she'll use hand sanitiser applied to a tissue for a quick clean. 3. Be prepared with appropriate medication Her next piece of advice is to bring along a well-stocked medicine kit, featuring the appropriate varieties. ‌ Sadaf carries a compact case filled with a range of medicinal items, including melatonin, plasters, and tablets for the common cold. Sadaf is convinced that after enduring many hours of travel, your body desperately needs time to rest and adapt, and "if it's not getting the rest it needs, you are going to exhaust yourself and get yourself sick." She believes it is important to get a a full eight hours of sleep, particularly during the first days of your trip, to beat jet lag. ‌ For her, the most effective remedy is taking melatonin before bedtime, which is a natural hormone produced by the pineal gland in the brain, playing a crucial role in regulating your sleep-wake cycle, according to the NHS. 4. Carry medication for stomach issues The travel guru's last tip is to pack medicine for "destinations where you're more likely to have stomach issues". For example, whenever Sadaf visits Pakistan, she never forgets to bring Dukoral, an oral vaccine that offers protection against cholera, a serious illness known for causing intense diarrhoea. Sadaf mentioned that it also protects against bacteria commonly transmitted through food and water. She further took Pepto-Bismol tablets daily, a treatment for various digestive issues, and shared that she managed to indulge in all sorts of local cuisine throughout her stay in Pakistan without any stomach problems.

DOWNLOAD THE APP

Get Started Now: Download the App

Ready to dive into the world of global news and events? Download our app today from your preferred app store and start exploring.
app-storeplay-store