Long-term monitoring of radioactivity in fish from New York waters.

As part of an environmental surveillance program operated by the New York State (NYS) Department of Health, measurements of various radionuclides in aquatic life (primarily fish) collected from waterways in NYS have occurred for decades. An investigation was undertaken to gain a better understanding of the occurrence, activity levels, and extent of radionuclide variations in aquatic life obtained from local waterways in relation to concentrations reported in fish from sites outside NYS (e.g., Pacific Ocean tuna). The man-made isotopes (137)Cs and (90)Sr were detectable at activities below 1 Bq/kg in the edible portions of fish from most NYS waterways, with the exception of greater activities in fish collected downstream of Brookhaven National Laboratory. Calculated effective doses resulting from eating the fish, estimated as 11-390 nSv/yr for (137)Cs and 0.3-7.9 nSv/yr for (90)Sr, are considered extremely low.

Performance of a commercial radon-in-water measurement kit.

Methods currently approved for the measurement of radon ((222)Rn) in water in New York State are liquid scintillation counting and emanation into alpha-scintillation cells. A passive system using an electret ion chamber (EIC) was evaluated as an alternative for the measurement of radon in water. Over 130 water samples from a community water supply containing 32BqL(-1) and 30 standards containing 686BqL(-1) were measured using the EIC method over 1- to 4-day exposure times. For comparison, identical samples were measured using liquid scintillation counting. Results of duplicate samples were typically within 5% for liquid scintillation counting and within 10% for the EIC. With respect to accuracy, the EIC produced results that were consistently low by 11-15%.

Long-term monitoring of radioactivity in surface air and deposition in New York State.

Gross-beta activities have been determined weekly for 22 y from filtered atmospheric aerosols at seven sites in New York State. The activities, ranging from 0.1 to 0.9 mBq m(-3), varied seasonally and were evaluated in terms of meteorological factors. Cosmogenic beryllium (7Be) concentrations were determined quarterly on the air filters and weekly in deposition collected at one site. Over 98% of the air filters contained observable activity concentrations of 7Be (mean of 3 mBq m(-3)) and 210Pb (mean of 1 mBq m(-3)). However, only 20% of deposition samples contained Be concentrations above analytical detection limits. Tritium (3H) concentrations were below detection limits in deposition samples at the background site, but were present on most samples collected near a H-processing facility. Measurements of 131I were conducted weekly on charcoal canisters, with only one site showing observable concentrations (mean of 1 mBq m(-3)), due to nearby incineration of dried municipal sludge containing patient waste from hospital treatments.

Airborne 131I at a background monitoring site.

As part of an environmental surveillance program, measurements of 131I in samples of atmospheric aerosols were determined in week-long collection periods at 0.3 km and 1.5 km from a municipal-sewage sludge incinerator located in Albany, New York. During an 11-month period when the sampler was temporarily located near the incinerator, sampling canisters of activated charcoal nearly always contained detectable airborne 131I activity (range of 0.1-6.0 mBq m(-3)). In contrast, remote concentrations where the sample was normally located were near or below analytical detection limits, both before and after the 11-month relocation. Activities of wet and dry fallout at both locations were below detection limits. The source of 131I in the aerosols associated with the sewage sludge was likely excreta from patients following medical treatments at local hospitals.