Federal officials said Sunday that “very low levels” of radioactive material have been detected in the United States as a result of damage to Japan’s nuclear plant, which has prompted Maryland and Virginia to keep an eye on levels in their respective states.

The levels of radioactive materials detected in this country thus far “were expected” and are “far below” the levels that would cause concern for public health, the federal Environmental Protection Agency said.

For the region, reports of elevated levels of radioactive material in rainwater have come in from Pennsylvania, according to state and federal officials. But health officials in Virginia and Maryland said that even the small elevations detected there have not been found in their states.

Officials “are not seeing that in any of the monitoring data” for Virginia, said Karen Remley, the state’s health commissioner. In Maryland, “Tests of rainwater . . . have found no detectable” radioactive iodine, said the Department of Health and Mental Hygiene.

Dr. Clifford Mitchell, Maryland’s assistant health director for environmental health and food protection, said his understanding was that the radioactive material found in Pennsylvania was radioactive iodine. Radioactive iodine is produced in nuclear fission and particles that escape into the air from a reactor can travel long distances in the atmosphere.

Meanwhile, radiation readings at the damaged Fukushima Daiichi nuclear plant was reported Sunday at its highest levels yet.

Maryland officials have found “no reason for public health concern,” said Dr. Joshua M. Sharfstein, head of the state’s health department, but they are “monitoring air , water and food supplies for trace amounts of radiation.”

In a statement, Robert M. Summers, acting secretary of Maryland’s Department of the Environment, said the state “will continue to be vigilant.”

The health department said it is not recommending any change in the activities of Maryland residents and specifically did not recommend that anyone take potassium iodide.

That chemical protects the thyroid gland against radioactive iodine, and is to be used in cases of exposure “far greater than any radiation exposure today in Maryland,’’ the department said.

Virginia’s health department said the low levels of radioactive material detected in the United States as a result of the Japanese incident do not raise concerns and “are expected to be relatively short in duration.” But the agency said it was taking several steps to “resolve any concerns.”

As one step, Virginia is moving up its routine quarterly radiological health division monitoring. The scheduled testing will begin Monday, the department said, monitoring radiation levels in air, drinking water vegetation and milk around the state.

In addition, the health department reminded residents “out of an abundance of caution that they should “avoid using rainwater collected in cisterns as drinking water.”

In discussing the specifics of the elevated readings made in Pennsylvania, the federal Centers for Disease Control said the numbers reported ranged from 40 to 100 picocuries per liter of water.

The readings are above the historical background levels in the area but “are still about 25 times below the level” that would be of concern for use as a sole source of water over a short time.

The CDC said this was true even for infants and pregnant or women who are breastfeeding, a sector of the population most sensitive to radiation.

Elevated readings were also reported in Massachusetts, of 79 picocuries per liter.

The CDC said in an official health advisory that although the elevated levels are not expected to last long, the EPA has moved to step up monitoring of potential exposure routes, to continue to verify that the radiation did not raise health concerns.