The transtheoretical model of change in adolescents: implications for injury prevention

INTRODUCTION: Many injury prevention interventions require changes in human behavior to reduce self-risk or risk to others. Promising injury prevention interventions may be discarded if they lack power to create a significant difference in outcomes when judging their ability to "move a person from nonaction or negative action to positive action (safety)." The transtheoretical model of change (TMC) allows greater sensitivity in detecting along the change process where an intervention may be effective. The stages of change consist of precontemplation, contemplation, preparation, action, maintenance, and termination. Change is not viewed as an "all or none phenomenon." METHOD: Use of the TMC was examined using a quasiexperimental, cross-over design involving high school agriculture students enrolled in 21 schools in Kentucky (n=9), Iowa (n=7), and Mississippi (n=5). A series of physical and narrative simulations (safety training exercises) were developed with a focus on preventing amputation, spinal cord injury, hypersensitivity pneumonitis, and noise-induced hearing loss. Contemplation and action, as part of the TMC, were measured using a 10-item, Likert-type, stages of change (SOC) instrument comprised of two subscales (reliability coefficients were.88 and.81, respectively). The final sample consisted of 790 students (373 treatment and 417 control). RESULTS: There was a significant group effect for both contemplation, F(1,732)=197.4; p<.0001, and action, F(1,730)=106.1; p<.0001. A convenience sample of 29 of the participating students was selected for follow-up farm visits 1 year postparticipation. Of these students, 25 (86%) had made safety behavior changes in their farm work. IMPACT ON INDUSTRY: The use of the TMC model can provide researchers with greater precision in examining intervention effectiveness in promoting change.     

Effects of Metal Mining and Milling on Boundary Waters of Yellowstone National Park, USA

/ Aquatic resources in Soda Butte Creek within Yellowstone National Park, USA, continue to be threatened by heavy metals from historical mining and milling activities that occurred upstream of the park's boundary. This includes the residue of gold, silver, and copper ore mining and processing in the early 1900s near Cooke City, Montana, just downstream of the creek's headwaters. Toxicity tests, using surrogate test species, and analyses of metals in water, sediments, and macroinvertebrate tissue were conducted from 1993 to 1995. Chronic toxicity to test species was greater in the spring than the fall and metal concentrations were elevated in the spring with copper exceeding water quality criteria in 1995. Tests with amphipods using pore water and whole sediment from the creek and copper concentrations in the tissue of macroinvertebrates and fish also suggest that copper is the metal of concern in the watershed. In order to understand current conditions in Soda Butte Creek, heavy metals, especially copper, must be considered important factors in the aquatic and riparian ecosystems within and along the creek extending into Yellowstone National Park.KEY WORDS: Mining; Metals; Toxicity; Biomonitoring; Copper; Yellowstone National Park     

The role of percutaneous umbilical blood sampling in the management of immune thrombocytopenic purpura

On consultation, percutaneous umbilical blood sampling (PUBS) was offered to women with immune thrombocytopenic purpura (ITP) to determine the mode and site of delivery prior to labour. Between January 1989 and December 1993, 41 pregnant women underwent PUBS. All women had a history of ITP, a platelet count less than 90 K, (+) antiplatelet antibody, and/or thrombocytopenia diagnosed early in pregnancy. PUBS was performed at term except in one patient with preterm labour, who underwent PUBS at 31 weeks' gestation. Patients with fetal platelet counts greater than 50 K returned to their referring physician for delivery. Records were complete in 39 pregnancies. Fetal blood was successfully obtained in 37 of 39 cases (95 per cent). Fetal platelet counts correlated with neonatal platelet counts in 36 of 37 cases (97 per cent). The interval between PUBS and delivery ranged from 0 to 31 days. Six of 37 fetuses (16 per cent) had significant fetal thrombocytopenia (<50 K). These six patients underwent Caesarean section. Vaginal delivery was recommended in all others. There were two procedure-related complications. There were no cases of intraventricular haemorrhage in any of the neonates. In conclusion, there is a high incidence of fetal thrombocytopenia in women with ITP. PUBS reliably detects fetal thrombocytopenia and is therefore useful in the perinatal planning of the mode and site of delivery.     

Prenatal diagnosis of fragile X syndrome: Management of the male fetus with a premutation

Direct detection of the fragile X mutation by DNA analysis has greatly simplified prenatal diagnosis of this disease. However, women carrying a fragile X premutation may pass their expanded trinucleotide repeat to sons without expansion to a full mutation. Such sons are predicted to be intellectually normal. In this situation, the accuracy with which the fetal status can be inferred from analysis of chorionic villus sample (CVS) DNA is unclear. We describe such a case, in which it was felt necessary to proceed to fetal blood sampling despite technically unambiguous DNA results from the CVS. The lack of prospective data means that this dilemma may be expected to recur over the next few years when performing prenatal diagnosis on fragile X premutation carriers.     

Genetic Diversity in the Endangered Lily Harperocallis flava and a Close Relative, Tofieldia racemosa

We examined genetic diversity in 464 individuals of the monotypic lily Harperocallis flava in its two habitats (seepage bogs and a roadside right-of-way) and five populations of a co-occurring related lily, Tofieldia racemosa. The endangered H. flava, endemic to the Apalachicola lowlands of the Florida panhandle, was monomorphic for the 22 loci scored. In contrast, T. racemosa had a high proportion of polymorphic loci ( P_s = 68.2%; P_p = 47.7%) with moderate genetic diversity (   H_es = 0.134; H_ep = 0.114). Estimated gene flow was moderately high ( Nm = 2.07) for T. racemosa, with most (93%) of the total genetic diversity found within populations. Despite the low level of genetic divergence, some isolation by distance was detected among T. racemosa populations. Harperocallis flava and other species without discernable genetic variation pose special problems for conservation biologists because genetic criteria are not available for the development of ex situ and in situ conservation and management strategies.     

Book reviews

Ecological Politics in an Age of Risk. Ulrich Beck, translated by Amos Weisz, 1995 Cambridge, Polity Press, first published Germany 1988. ISBN 0 7456 077632, hb £39.50; ISBN 0 7456 13772, pk £12.95

Environmentally Sustainable Business: a local and regional perspective. Peter Roberts, 1995, London, Paul Chapman. ISBN 1 85396 240 6, price not given

Methods of Environmental Impact Assessment. Peter Morris & Riki Therivel (Eds) 1995, London, UCL Press, 378 pp. ISBN 1 85728 117 9, hb £45.00; 1 85728 118 7, pb £14.95

A Guide to Local Environmental Auditing. Hugh Barton & Noel Bruder, 1995, London, Earthscan, 370 pp. ISBN 1 85 383 2340, pb £18.95

Household Waste Recycling. Richard Waite, 1995, London, Earthscan, ISBN 1 8538 3 2421, hb £29.95

A Seed in Time: Proceedings of the 3rd International Conference on Urban and Community Forestry. Forestry Commission, 1994. ISBN 0 885 38 328 3, £9.50 inc p&p (Copies available from: Marcus Sangster, Forestry Commission, 231 Corstorphine Road, Edinburgh EH12 7AT)

Environmental Policy in New Zealand: the politics of clean and green? Tom Buhrs & Robert Bartlett, 1993, Auckland, Oxford University Press viii + 192 pp.

Green Politics. Stephen Rainbow, 1993, Auckland, Oxford University Press xv + 106 pp.

The Future of Community Lands: human resources. E. Ndione, P. DeLeener, M. Ndiaye, P. Jacolin & J.-P. Perier, 1995, London, Intermediate Technology, 236 pp. ISBN 1 339 2480, £14.95     

ASSESSING THE ECONOMIC BENEFITS OF GROUND WATER FOR ENVIRONMENTAL POLICY DECISIONS1

ABSTRACT: The full range of environmental and economic services of ground water need to be accounted for in policy decisions. Non-recognition of these services imputes a lower value for the ground water resource in establishing policies. We describe a conceptual framework for identifying and measuring the economic value of groundwater. The valuation framework links changes in physical characteristics of ground water to services provided by ground water and the economic effects of changes in ground water services. In addition to the framework, we develop a general protocol to follow for assessing the benefits of ground water policies. Application of the protocol will aid in establishing structure and consistency across policy assessments and improve the accuracy and completeness of benefit estimates, avoid double-counting problems, and eliminate duplication of ground water valuation efforts.     

Role of wetlands in reducing phosphorus loading to surface water in eight watersheds in the Lake Champlain Basin

A landscape-level approach was applied to eight rural watersheds to assess the role that wetlands play in reducing phosphorus loading to surface waters in the Lake Champlain Basin. Variables summarizing various characteristics of wetlands within a watershed were calculated using a geographic information system and then compared to measured phosphorus loading through multiple regression analyses. The inclusion of a variable based on the area of riparian wetlands located along low- and medium-order streams in conjunction with the area of agricultural and nonwetland forested lands explained 88% of the variance in phosphorus loading to surface waters. The best fit model coefficients (P_load = 0.86Ag + 0.64For – 30Ripwet + 160) suggest that a hectare of riparian wetland may be many times more important in reducing phosphorus than an agricultural hectare is in producing phosphorus. These results provide additional support for the concept that protection of riparian wetlands is an important management strategy for controlling stream water quality in multiuse landscapes.