RADIUM - 226 IN GROUND WATER OF WEST CENTRAL FLORIDA1

ABSTRACT: Principal U.S. phosphate production is from central Florida where mining, processing, and waste disposal practices intimately associate the industry with water resouces. Available radium-226 data from 1966 and from 1973–1976 in mined and unmined mincralized areas and nonmineralized areas in the primary study area in Polk, Hardee, Hillsborough, Manatee, and De Soto counties were studied using log-normal probability plots and nonparametric statistical tests for significant difference as functions of time, depth, and location. Plots of radium in the water table and Floridan aquifers for mineralized and nonmineralized areas indicate that neither phosphate mineralization nor the industry is a probable factor. For the Lower Floridan aquifer, three separate radium populations are indicated with geometric means of 0.7, 3, and 10 pCi/1. Geometric mean radium-226 content of the water table aquifer is 0.17 pCi/1. Radium in the Floridan aquifer in Manatee and Sarasota Counties is elevated relative to that in the water table and in other areas of Florida. For Sarasota County, geometric mean radium content of the water table is 15 pCi/l versus 7.5 pCi/l in the Floridan. Potential sources include shallow phosphate sediments and monazite sands and possibly crystalline basement rocks or other strata unrelated to phosphatic zones of current economic interest. The existing radium-226 data base is rather marginal in terms of number and spatial distribution of analyses, particularly for the water table and Upper Floridan aquifer. Existing radium data do not substantiate widespread contamination of ground water as a result of the phosphate industry. However, local contamination associated with specific operations has occurred.     

Reliability of differing densities of sample grids used for the monitoring of forest condition in Europe

Concern about the possible deterioration of forest health led to the establishment in the 1980s of inventories of forest condition throughout Europe. International standardisation of the programmes was sought and a number of recommendations were made concerning sampling and assessment procedures. One of the most important rulings was that the assessment should be made on a systematic grid, the minimum density of which was 16×16 km. However, many countries adopted denser sampling grids, with 4×4 km being used in several countries and 1×1 km being used in the Netherlands. With five or more years of monitoring completed, there is a growing belief that a rapid and irreversible decline in forest health is not occurring. Consequently, some countries/regions are seeking to reduce their annual investment in forest health monitoring.The precision of national/regional estimates of forest health can be directly related to the sample size. As the sample size decreases, so also does the precision of the estimates. This is illustrated using data collected in Switzerland in 1992 and using grid densities of 4×4 km, 8×8 km, 12×12 km and 16×16 km. The value of the data is dependent on the sample size and the degree to which it is broken down (by region or species). The loss of precision associated with most subdivisions at the 8×8 km grid level remains acceptable, but a sharp deterioration in the precision occurs at the 12×12 km and 16×16 km grid levels. This has considerable implications for the interpretation of the inventories from those countries using a 16×16 km grid. In Switzerland, a reduction from the current 4×4 km grid to an 8×8 km grid (i.e. 75% reduction in sample size) would have relatively little impact on the overall results from the annual inventories of forest health.     

Occupational Health Care in Small and Medium-Sized Enterprises—Introduction of Services to Craftsmen by Using Their Professional Networks

In order to ensure equality of occupational health care among employees of small and medium-sized enterprises (SMEs) and of larger companies, amendments in the regulations of the numerous German accident insurance funds had to be made to provide for full availability of services, as requested by German and European law. According to these amendments, sectors formerly exempted due to small size and due to lack of an adequate number of qualified personnel, had to be covered by occupational health care. In order to reach this target group new strategies of care delivery had to be developed, making use of pre-existing infrastructure and networks.

In Germany, district trade association (Kreishandwerkerschaften) have proved to be very effective for introducing occupational safety and health care into SMEs by either hiring external multidisciplinary services or by establishing a common service to be used by all associated crafts establishments. In a study conducted by the Federal Office for Health and Safety at Work in 1996 (Boldt, Gille, &Grahl, 1997), 7 district trade association were looked at in detail for their strategies. The results were discussed and supplemented in a 2-day workshop.     

Industrial odours as environmental stressors: Exposure-annoyance associations and their modification by coping, age and perceived health

The degree of association between industrial odours and reported annoyance was investigated by means of field studies in four German cities, namely Duisburg (n = 400), Brühl (n = 539), Dortmund (n = 400) and Rodenkirchen (n = 200). The degree of odour exposure was assessed by estimating the frequency of odours by means of systematic field observations, whereas annoyance was assessed by personal interviews using standardized questionnaires. Both studies revealed highly significant associations between odour exposure and degree of annoyance. Odour annoyance was correlated with personal factors: age was negatively related to annoyance, whereas dissatisfaction with health exhibited positive associations with annoyance. Coping strategies were also associated with odour annoyance: high scores in problem-oriented coping strategies increased annoyance, whereas high scores in avoidance coping reduced annoyance. Coping strategies based upon the reduction of emotional stress were not associated with annoyance. Since none of the interaction terms of the full regression model proved significant, no true moderators were identified. In order to check for aquiescence bias, people who were interviewed personally were compared with those who could not be approached directly and who were therefore contacted by mail. Despite some significant differences in terms of gender, education, occupation, problem-oriented coping and avoidance coping, both groups did not differ in terms of annoyance.     

Effects of seasonal pack ice on the distribution of macrozooplankton and micronekton in the northwestern Weddell Sea

The presence of mesopelagic organisms in the guts of surface-foraging seabirds feeding in open areas within seasonal pack ice in the Antarctic has given rise to questions regarding the effects of pack ice on the underlying mesopelagic community. Bottom-moored free-vehicle acoustic instruments were used in concert with midwater trawls and baited traps to examine the abundance, size distribution and vertical distribution of pelagic organisms in the uppermost 100 m of the water column during the austral spring of 1992 in two areas of the northwestern Weddell Sea, one covered by seasonal pack icc and the other free of ice cover. Acoustic largets were more abundant and significantly larger at the open-water station than beneath pack ice. However, targets at the ice-covered site exhibited a pronounced diel pattern, with the largest targets detected only at night. Samples from night trawls at the icecovered site contained several species of large, vertically-migrating mesopelagic fishes, whereas these species were absent from trawls taken during the day. In addition, baited traps deployed in pack ice just beneath the ice-water interface collected large numbers of scavenging lysianassoid amphipods, while deeper traps beneath the ice and traps at the open-water station were empty, indicating the presence of a scavenging community associated with the undersurface of the ice. These results sapport the idea that mesopelagic organisms migrate closer to the surface beneath pack ice than in open water, exposing them to possible predation by surface-foraging seabirds.