Ammonia Pollution Reaches Human Bodies Via Air, Water, Food

Bacteria Could Someday Help the Body Clear Dangerous Ammonia

Ammonia pollution from farms, factories, and city traffic can end up in the air people breathe, the water they drink, and the food they eat. A new scientific review links it, and the chemicals it breaks down into, to breathing trouble, digestive cancers, and liver damage, then floats an unusual fix for dangerous ammonia buildup in the blood: bacteria that live off the stuff.

Published in The Innovation Reviews, the paper pulls together existing research on where ammonia comes from and how it harms health. Ammonia also forms inside every body when protein breaks down, and a healthy liver turns it into urea, a milder substance flushed out as waste. Trouble starts when a damaged liver falls behind and ammonia piles up in the blood, which the review says can cloud thinking and disrupt movement.

Treatments for that buildup, mainly dialysis and drugs, have real limits. So the authors look to nature, where bacteria in soil and water break ammonia down for energy. Borrowing those microbes or their genes may eventually offer a more flexible and effective option, the paper argues, but its proposed strategies are still ideas, not proven treatments.

Farming Drives Most Human-Caused Ammonia Pollution

Agriculture accounts for roughly 80 to 90 percent of human-caused ammonia emissions worldwide, according to the review. Fertilizer, fish and shellfish farming, and livestock and poultry waste all release it. China, India, the United States, and Europe are named as major hotspots.

Factories, diesel vehicles running on low-quality urea, and badly managed garbage and sewage add more. Burning coal and other fuels creates gases that join farm ammonia in the air to form fine particles, which are linked to asthma, bronchitis, chronic lung disease, and heart problems. One 2015 study cited in the review tied outdoor fine particles, which ammonia helps form, to more than 5 percent of premature deaths worldwide.

Direct contact irritates the eyes and airways, and years of living near farms or industrial sites may damage the lining of the nose and mouth. In animal research cited in the review, ammonia exposure even shifted the bacteria living in the nose, with similar changes showing up in the colon, a hint that its effects reach well beyond the point of contact.

Ammonia that lands in soil can turn into nitrate, which seeps into drinking water, where the World Health Organization has set strict limits on it. Crops, especially leafy vegetables, soak up nitrate from the soil and concentrate it in the parts people eat. In infants, the body can convert nitrate into a form that keeps blood from carrying oxygen properly, a condition called blue baby syndrome. Nitrate and nitrite can also react in the stomach to form cancer-causing chemicals, and the review says long-term intake raises the risk of stomach, esophageal, and other digestive cancers. Runoff feeds algae blooms too, and their toxins can damage the liver when they reach people through water, fish, or shellfish.

Liver Damage Lets Ammonia Build Up and Upset Gut Bacteria

Beyond the liver, gut bacteria pitch in with ammonia cleanup. The review describes several, including one strain that lowered ammonia in the brain and may help prevent liver-related brain problems.

When the liver is badly damaged, that cleanup system stalls, and the gut community changes along with it. In mice with chronic ammonia buildup, some bacterial groups increased while Lactobacillus, a group common in probiotics, declined. In people with cirrhosis, or liver scarring, an enzyme becomes more active and raises ammonia levels in the intestine.

Current Ammonia Treatments Are Costly and Limited

Dialysis can temporarily bring ammonia down, and a liver transplant replaces the failing organ. Both are expensive, and neither restores the gut’s bacterial balance, the review notes. Drugs have downsides too: one that rebalances gut bacteria has caused severe diarrhea in some patients, and a syrup that feeds helpful bacteria can cause dehydration when overused. Probiotics show promise in some studies, but research on the best strains is thin and the products used in studies are costly. Long treatment times leave many patients complaining, the review says.

Ammonia-Eating Bacteria Could Inspire New Gut Treatments

Certain bacteria in soil, fresh water, and oceans live off ammonia as part of nature’s nitrogen recycling. Some convert it straight into nitrogen gas, skipping byproducts tied to water pollution and health risks.

Four ideas are offered for putting this chemistry to work: using bacteria native to the gut instead of lab strains; using dead bacteria whose enzymes still work, which may ease safety worries; holding enzymes or cells in place to remove ammonia, either in the gut or in a machine outside the body; and editing the gut’s whole microbial community rather than one strain. Earlier studies cited in the review found that gut bacteria, including engineered ones, can lower ammonia inside the body, but these four strategies remain proposals.

Bacteria that nature already built to handle ammonia are a sensible place to look for better ways to treat dangerous blood buildup, though patient trials, not a literature review, will have to show whether they work.

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Disclaimer: This article is for general informational purposes only and is not medical advice. It summarizes a literature review, not a clinical trial, and its proposed treatments have not been proven in patients. Anyone concerned about ammonia exposure, liver health, or any medical condition should consult a qualified health professional.

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