Purus Learn
What’s in your food, in plain English.
Short guides to heavy metals and pesticides in everyday food. Every number comes from a named source, like the FDA, EPA, USDA or an independent lab test, and every guide ends with things you can actually do.
Heavy metals
Lead, arsenic, cadmium and mercury get into food from soil and water. Where they show up, and how to eat less of them.
Heavy metals
Heavy metals in food: where lead, arsenic, cadmium and mercury show up
Traces of heavy metals are in many everyday foods, because they’re in the soil, water and air where food is grown. A few foods carry more, and a varied diet helps keep any one from adding up.
68%
of FDA Total Diet Study results for lead, arsenic, cadmium and mercury were below what labs could detect (2018–2020)
Heavy metals
Lead in protein powder: what the tests found and how to choose
A 2025 test found that most protein powders and shakes went over a strict lead benchmark in a single serving. Here’s what that means, and how to choose one with less.
2 in 3
protein powders and shakes tested had more lead per serving than a strict daily benchmark
Heavy metals
Lead in cinnamon: the recalls, the tests and how to buy safer cinnamon
In 2023, cinnamon applesauce pouches poisoned hundreds of young children with lead. FDA alerts since then have flagged more ground cinnamon. Here’s what to know before you buy.
566
cases of lead poisoning the CDC linked to cinnamon applesauce pouches, over half in children under 2
Heavy metals
Arsenic in rice: the lowest-arsenic kinds and how to cook it
Rice soaks up more arsenic from soil and water than other grains. The kind you buy and the way you cook it can cut what you eat by about half.
40–60%
less inorganic arsenic when rice is cooked in lots of water and drained, like pasta
Heavy metals
Mercury in fish: salmon, swordfish and the lowest-mercury picks
Popular fish like salmon, shrimp and canned light tuna are low in mercury. A handful of big predator fish have far more.
45×
more mercury in swordfish than in salmon, on average (0.995 vs 0.022 ppm)
Heavy metals
Mercury in tuna: canned light, albacore, ahi and how much to eat
All tuna has some mercury, but the kind matters most. Canned light tuna has about a third as much as albacore, and bigeye and bluefin have the most.
2.8×
as much mercury in canned albacore as in canned light tuna, on average (0.350 vs 0.126 ppm)
Heavy metals
Cadmium in chocolate: why dark chocolate has more, and how to choose
Cacao trees pull cadmium up from the soil into their beans, and lead settles on the beans after harvest. The darker the chocolate, the more cadmium it tends to have.
23 of 28
dark chocolate bars in a 2022 test had enough lead or cadmium that an ounce a day put an adult over CR’s level
Heavy metals
Heavy metals in baby food: what parents can do
Lead, arsenic, cadmium and mercury come from soil and water, so traces turn up in many baby foods. A few easy habits lower how much your baby gets.
94%
of 168 baby foods tested in 2019 had detectable lead
Pesticides
What residue testing finds on produce and grains, what the limits mean, and when organic is worth it.
Pesticides
Glyphosate in food: where it shows up and what the science says
Glyphosate is one of the most widely used weed killers in the world, and traces of it turn up in grains, beans and the people who eat them. Here’s what’s known and what’s still argued.
8 in 10
Americans age 6 and up who were tested had glyphosate in their urine (2013–2014)
Pesticides
Glyphosate-free oats: why oats test high and how to choose
Some oats get a dose of weed killer shortly before harvest, and most conventional oat foods test positive for it. Here’s how to find oats with little or none.
43 of 45
conventional oat samples had glyphosate in EWG’s first 2018 tests
Pesticides
The Dirty Dozen 2026: the full list, and when organic is worth it
Spinach tops this year’s list of produce with the most pesticide residues. Here’s the full 2026 Dirty Dozen and Clean Fifteen, and how to use them without eating less produce.
Spinach
is #1 on the 2026 Dirty Dozen, ahead of kale, collard and mustard greens
Labels and testing
How to read lab reports, test claims and seals, so you can check a product for yourself.
Eating well
Grocery lists and meal plans that put the research to work, one week at a time.
Eating well
Healthy grocery list: what to buy, aisle by aisle
A list built on the 2025–2030 Dietary Guidelines, sorted the way you shop, with the picks that keep heavy metals and pesticides down.
3 + 2
servings of vegetables and fruit a day for a 2,000-calorie diet, in the 2025–2030 Dietary Guidelines
Eating well
Clean eating meal plan: 7 days of simple, whole-food meals
“Clean eating” has no official definition. Here it means whole foods, enough protein, and fewer heavy metals and pesticides. A week of meals to start from.
1.2–1.6 g
of protein per kilogram of body weight a day, in the 2025–2030 Dietary Guidelines
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These guides are for general information, not medical advice. If you are pregnant, feeding a baby, or managing a health condition, talk with your doctor or a registered dietitian.