President Joe Biden declared an emergency over lead-in-water contamination in the US Virgin Islands earlier this week after tests on St Croix revealed levels more than 100 times the limits set by the Environmental Protection Agency – among the worst results a US community has seen in decades.

“On a personal level, it’s been frightening and frustrating,” said resident Frandelle Gerard, executive director of Crucian Heritage and Nature Tourism, Incorporation.

Officials told residents to stop using their taps and began distributing vouchers for bottled water. Lead can have devastating effects on childhood development, behaviour and IQ scores.

But experts consulted by The Associated Press said the frightening results may be false because they came from testing that does not meet EPA standards.

“The data should be thrown into the garbage,” said Marc Edwards, a Virginia Tech lead and water expert who helped identify the lead problems in Flint, Michigan.

If the information given to St Croix residents turns out to be bad, it won’t be the first time that’s happened. Poor information often plagues communities, and they are often majority-Black communities, facing lead crises, leaving people unsure what to believe. In Flint, officials initially concealed high lead levels. When levels spiked in Newark, officials emphasised the safety of the city’s reservoirs even though it is lead pipes – not the source – that are usually the problem. In Benton Harbor, Michigan, residents waited months for officials to confirm that filters truly work, relying on bottled water.

On the Caribbean island of St Croix, officials avoided some of those pitfalls and quickly told residents of the results. The governor declared an emergency.

“This is not something that we shy away from talking about,” said Andrew Smith, head of the Virgin Islands Water and Power Authority.

Edwards does not believe the sky-high results reflect reality and said the problem is how the samples were collected. For lead testing, workers usually take water from a household faucet. But the samples that tested so high on St Croix were collected from the meter.

“When you (unscrew) it, you are literally ripping the leaded-brass apart and a chunk of leaded-brass gets in your sample,” he said. It produces artificially high results.

Tom Neltner, a chemical and lead expert at the Environmental Defense Fund, agreed that testing from the water meter isn’t accurate. “There’s a lot of oddities” about how St Croix’s sampling was done, he said.

Parents in St Croix therefore still have no idea how much lead their kids were consuming.