Fates of cadmium introduced into channels microcosm

Five 10 μg Cd·l^?1 were continuously input to aquatic microcosm channels for one year. Cadmium accumulation in both biotic and abiotic components was determined. Cadmium inputs and outputs equilibrated within approximately 20 days of initial Cd inputs. Most community components accumulated Cd proportional to Cd water concentrations. Equilibrium Cd concentrations of sediments, aufwuchs, macrophytes, chironomids, and mosquito fish exposed to 10 μg Cd·l^?1 were 0.59, 55, 250, 40, and 40 μg Cd·g^?1, dry weight, respectively. Cadmium was rapidly eliminated from all biotic components when Cd inputs were terminated. Cadmium concentrations were similar to those in control channels within a few weeks in the aufwuchs community to a few months in macrophytes after Cd inputs were terminated. Cadmium uptake fluxes by the aufwuchs community and mosquito fish were first order, with respect to Cd concentration in the water. The rate constants for uptake and depuration for the aufwuchs community were 0.42 and 0.66 d^?1, respectively (concentration basis). The rate constants for uptake and depuration of Cd by mosquitofish were approximately 25 and 0.004 d^?1, respectively (concentration basis). Cadmium concentrations in organic headpool sediments had not significantly decreased six months after cessation of Cd inputs, which indicates that the abiotic half time for contaminated organic sediments is very long. Half times for elimination from channel sand sediments were 72 and 38 d for 5 and 10 μg·l^?1 exposure, respectively, after Cd inputs were terminated Cd concentrations in macroinvertebrates varied seasonally. The carrying capacity of the channels microcosm limited the number of samples of secondary and tertiary consumers which could be sampled. It was concluded that concluded that experimental channels of the size described here were not appropriate as screening tools for the fates of trace contaminants, but were effective for the study of trace contaminants, especially in conjunction with mathematical modeling efforts and less complex laboratory studies.     

Biamnial elevated alpha-fetoprotein and positive acetylcholinesterase in twins,one with anencephaly

Anencephaly in twin B was accompanied by elevated amniotic fluid alpha-fetoprotein (AFP) and a positive acetylcholinesterase (AChE) band on gel electrophoresis in both twin sacs, although twin A was normal. AChE results did not help distinguish the false positive AFP in this set of twins, implying that AChE may diffuse transamniotically as has been previously postulated for AFP. In light of the low concordance rate for neural tube defects in twins, patient counselling in this situation must include the information that AFP and AChE may be falsely elevated in normal twin when the other twin has a neural tube defect.     

Awareness of zero tolerance laws in three states

PROBLEM: A prior study indicated that zero tolerance laws differ in their enforceability and likelihood of enforcement, with California's law being easier to enforce than New York's, and New Mexico's being the hardest of all. The question is, do these differences in enforcement affect teenagers' knowledge and perception of these laws? METHOD: A telephone survey was conducted to investigate awareness of the laws among 17-20 year olds in these three states and perceptions of enforcement. RESULTS: Estimated percentages of teenagers who knew of the laws were much higher in New York and California (71% and 65%, respectively) than in New Mexico (34%). Perceptions that police were enforcing the law, that licenses could be suspended, and that penalties were often applied were also lowest in New Mexico. IMPACT ON INDUSTRY: The potential of zero tolerance laws will not be realized without better awareness among young people. Full enforcement of the laws accompanied by publicity about the enforcement is recommended. Changes to the laws and their application may encourage enforcement efforts.     

Foraging differences between cross-fostered honeybee workers (Apis mellifera) of European and Africanized races

Summary Foraging differences between cross-fostered honeybee workers of European and Africanized races in South America are described. Africanized workers began foraging at earlier ages than European workers in colonies of their own races, but cross-fostered workers began foraging at the same age as workers in the colonies in which they were placed. Some differences in the mean time spent foraging per hour and the mean number of flights per hour were also found. The results suggest two major factors determining differences in division of labor between Africanized and European bees: 1) the colony characteristics by which foraging age is determined, and 2) the responses of individual workers to hive environment. A hypothesis to explain these results is presented based on higher levels of foraging stimuli in Africanized colonies as well as a higher stimulus threshold for Africanized workers.     

Nutrient and trace elements in soil and desert vegetation of southern Idaho

Concentrations of thirty elements were measured in strong-acid extracts of soil, sagebrush (Artemisia tridentata spp.) leaves and perennial grass from the Idaho National Engineering Laboratory (INEL) and two reference sites in southern Idaho. A bicarbonate-chelating extract of soil was used to estimate plant-available concentrations. The results provide baseline data prior to start-up of a coal-fired steam generation facility on the INEL and other developments in the region. In addition, existing impact from effluents from thirty years of a nuclear fuel reprocessing facility on the INEL was evaluated. Based on the spatial distribution of element concentrations, as well as comparison with references sites, we conclude that concentrations of Zn, and perhaps Ni, Cd, and V, are currently elevated around the fuel reprocessing facility. The spatial distribution of these elements is similar to that of ¹³⁷Cs in soil, a radionuclide which is emitted by the facility. Sagebrush and soil appear more responsive than perennial grass for long-term monitoring of element concentrations in this semi-arid environment.     

Trisomy 20 mosaicism confirmed in a phenotypically normal liveborn

Prenatal diagnosis of trisomy 20 mosaicism in this case was based on cytogenetic analysis of cultured amniotic fluid cells (23/52 cells were trisomy 20 representing cells from each of four primary cultures). The pregnancy continued to term and the mosaicism was confirmed in the phenotypically normal male neonate by analysis of cultured foreskin fibroblasts (7/49 cells + 20) and placental cells 20/20 cells + 20) whereas the peripheral lymphocytes were cytogenetically normal (20/20 cells were 46,XY). This represents the first confirmation of trisomy 20 mosaicism in a phenotypically normal full-term neonate.     

Informing the development of decision support tools for risk management: the case of electrical and magnetic fields

This paper describes tools developed through a community consultative process to help decision makers manage electrical and magnetic fields (EMF) health risk. The process involved in‐depth interviews with experts (N=12) and focus group discussions with seven different stakeholder groups. The results reveal commonly held intense public concerns about the long‐term health effects of EMF. These concerns were further reinforced by the lack of public trust in both government and industry with regards to EMF risk management. Overall, the participants wanted tools that can be used to manage EMF information, scientific uncertainty about EMF and the complex environment in which EMF issues are embedded. The findings contributed to a mapping out of response formats to address public concerns related to risk, hazard, trust, accountability and fairness across a range of stakeholder groups. These tools and their roles in the management of complex and variable risks, involving new circumstances (e.g. privatization) and information (e.g. new scientific studies) are presented. The importance of recognizing and working with uncertainty through adaptive management strategies, using qualitative approaches, is also discussed.     

Mass media and park management: Reaching the public beyond the park boundary

Summary Mass media can be used to reach a large audience, create knowledge and spread information, and lead to changes in attitudes. Newspapers, radio and television offer a valuable mechanism for parks and preserves to influence the public beyond their boundaries. With the park system in Sabah, Malaysia, a series of newspaper articles with the goal of increasing public interest in parks was developed. Although lack of prior data precluded an assessment of changes in park visitation rates, secondary effects such as calls from politicians and the business community, suggested tha print media is an effective way of reaching specific audiences with environmental messages in Sabah. Furthermore, the parks can serve a useful service by providing environmental information to the public. A survey of mass media in Sabah revealed a weekly average of only two newspaper articles and one hour of television viewing time devoted to natural resource conservation issues.Dr Susan K. Jacobson is Coordinator for the Program for Studies in Tropical Conservation in the Department of Wildlife and Range Sciences at the University of Florida. The paper describes research which she undertook in Sabah, Malaysia.     

Prenatal diagnostic testing for familial dysautonomia using linked genetic markers

Familial dysautonomia (FD), a recessively inherited disease, has been mapped to chromosome 9q31. Highly polymorphic dinucleotide repeat markers flanking the genetic locus and at the same genetic location have been identified. We describe the prenatal diagnosis of FD using linkage and linkage disequilibrium analyses with these markers. Twelve families were analysed for informativeness and of these, seven went on to have prenatal testing (a total of eight fetuses tested). All of these fetuses were predicted to be heterozygous unaffected (FD carriers). Seven fetuses have come to term and are normal. In the absence of a recombinant proband, a panel of three proximal and three distal markers is sufficient to provide informative flanking markers and an 87–96 per cent likelihood of a highly predictive test. In an additional family at 1:4 risk for FD, no DNA was available from the propositus. This family was analysed using linkage disequilibrium to the #18 allele of the tightly linked marker D9S58 in conjunction with linkage analysis using data from two unaffected children. Prenatal diagnosis in this family indicated an affected fetus.     

The effects of ergonomics training on the knowledge, attitudes, and practices of teleworkers

PROBLEM: The rapid growth of teleworking has raised several social and legal issues regarding an employer's responsibility for the safety of an employee's home office. In this paper, researchers discuss the need for safety training for teleworkers and the effectiveness of a home office ergonomics training program. METHOD: Study participants (N = 50) were randomly assigned into a treatment or control group. The treatment group completed the ergonomics training and a pre- and posttest. The control group completed the pre- and posttests without training. RESULTS: The study demonstrated the need for teleworker ergonomics training. More than 85% of participants had not received teleworker training before, and 44% had experienced pain or discomfort while teleworking. Participants who completed the training significantly improved their scores on knowledge, attitude, and practices subtests. In a follow-up survey, participants indicated that they had made ergonomic changes to their offices based on the training. Several participants indicated that the pain or discomfort that they had been experiencing was eliminated or reduced as a result of the training.