(WHNT) – According to research by Consumer Reports (CR), brands of dark chocolate are being called as they could potentially contain dangerous amounts of heavy metals.

Our news affiliate, CBS, says that scientists at CR measured the amount of heavy metals in 28 of the most popular brands of dark chocolate. They found lead and cadmium in all of them.

For 23 of those, the researchers say that consuming just one ounce daily would put an adult over a level for at least one of the harmful metals. Five of the bars were above those levels for both cadmium and lead.

“But there are risks for people of any age,” Tunde Akinleye, the CR food safety researcher who led the testing, told CBS. Constant exposure to lead in adults can lead to serious health issues down the road, including issues with your nervous system hypertension and reproductive issues.

Scientists at CR found that five of the bars had relatively low levels of both metals.

“That shows it’s possible for companies to make products with lower amounts of heavy metals — and for consumers to find safer products that they enjoy,” Akinleye said.

According to CBS, the team at CR used California’s maximum allowable doses — 0.5 micrograms of lead and 4.1 micrograms of cadmium — since there are no federal limits. They found that one ounce of Hershey’s Special Dark Mildly Sweet Chocolate contained lead 265% over what is allowed in Cali., and Trader Joe’s Dark Chocolate 72% Cacao held 192% more.

In August, the National Confectioners Association released research on how to effectively reduce the amounts of lead and cadmium.

The study was conducted in partnership with As You Sow as a part of the settlement reached regarding a California law that requires businesses to warn people about significant exposure to chemicals that can cause cancer, birth defects or any reproductive harm.

CR also suggested several safer choices, including: