Sometimes, saving money the wrong way can cost you and those around you dearly. One seemingly harmless habit — continuing to use old, moldy chopsticks — has been linked to a tragic case in which four members of the same family developed liver cancer.

Tan Dunci, a specialist from the Department of Clinical Toxicology at Linkou Chang Gung Memorial Hospital (Taiwan), warns:

“Cancer-causing toxins can exist right around us, in places we interact with every day without realizing it.”

She shared a real case from her professional experience involving a household in which four people were diagnosed with liver cancer due to improper use of bamboo chopsticks.

Moldy Chopsticks: A Hidden but Deadly Risk

According to Tan, the first person to fall ill was the grandfather, nearly 70 years old, who was rushed to the hospital with severe abdominal pain. His family initially assumed the diagnosis was related to age, poor diet, and alcohol consumption. However, not long afterward, his daughter-in-law — a full-time homemaker in her 40s — was also diagnosed with liver cancer.

Because the two patients were not blood relatives yet developed the same disease, the family grew suspicious and invited experts to inspect their home. Shockingly, as soon as the specialist entered the kitchen, she exclaimed:

“Using bamboo chopsticks that are black with mold like this is no different from drinking poison. They contain aflatoxin, a powerful cancer-causing toxin.”

The mother was devastated. Her family had used bamboo chopsticks for decades out of habit and thriftiness. Even when the chopsticks became heavily moldy and difficult to clean, attempts to throw them away were often stopped by her father-in-law, who believed that mold from bamboo was harmless and could be removed by scrubbing, boiling, or soaking in hot water.

Aflatoxin: A Group 1 Carcinogen

Once the cause was identified, the woman immediately followed medical advice and took the remaining family members for screening. The results revealed that both of her children had also developed liver cancer — fortunately detected at an early stage. Her husband, who traveled frequently and ate fewer meals at home, had absorbed less of the toxin and was diagnosed with stage 2 liver fibrosis, which was treatable.

Tan Dunci explains that not only moldy chopsticks, but also moldy wooden cutting boards and spoiled food can contain aflatoxin. This toxin is classified by the World Health Organization (WHO) as a Group 1 carcinogen, the highest risk category.

She warns:

• Aflatoxin is 68 times more toxic than arsenic

• 100 times more toxic than potassium cyanide

• Even very small amounts can cause acute poisoning, liver failure, kidney failure, or death

Why Bamboo and Wooden Chopsticks Are Especially Dangerous

Although bamboo chopsticks are common in households, they are highly prone to mold, especially when used for long periods or stored improperly. Over time, they become rough, cracked, and chipped, allowing water and food residue to seep in. This creates a damp environment where mold thrives and aflatoxin can form.

Even more alarming, aflatoxin is extremely heat-resistant. It cannot be destroyed by boiling, steaming, or cooking with high temperatures.

Discard Chopsticks Immediately If They Have These Signs

Experts recommend throwing away bamboo or wooden chopsticks immediately if they:

• Have many scratches or cracks

• Show even the smallest amount of mold

Even if chopsticks appear normal to the naked eye, they should be replaced every 3–6 months.

Proper Cleaning and Storage Tips

To reduce risk:

• Wash chopsticks one by one using a dish sponge, following the grain or grooves

• Avoid rubbing many chopsticks together in your hands, as this does not clean them thoroughly

• Dry them completely in a well-ventilated area, preferably under sunlight, before storing

• Regularly disinfect chopsticks; if no specialized equipment is available, washing thoroughly and briefly boiling or soaking them in hot water can help reduce mold — but this does not eliminate aflatoxin once present

When it comes to moldy kitchen utensils, especially chopsticks, replacing them promptly is not wasteful — it can be lifesaving.