Polybrominated diphenyl ethers (PBDE) in serum: findings from a US cohort of consumers of sport-caught fish

Polybrominated diphenyl ethers (PBDEs) have been used as flame retardants in foams, fabrics and plastics, and are common contaminants of household air and dust and bioaccumulate in wildlife, and are detectable in human tissues and in fish and animal food products. In the Great Lakes Basin sport fish consumption has been demonstrated to be an important source of PCB and DDE exposure. PBDEs are present in the same sport fish but prior to our study the contribution to human PBDE body burdens from Great Lakes sport fish consumption had not been investigated. This study was designed to assess PBDE, PCB and 1,1-bis(4-chlorophenyl)-2,2-dichloroethene (DDE) serum concentrations in an existing cohort of 508 frequent and infrequent consumers of sport-caught fish living in five Great Lake states. BDE congeners 47 and 99 were identified in the majority of blood samples, 98% and 62% respectively. summation operatorPBDE levels were positively associated with age, hours spent outdoors, DDE, summation operatorPCB, years of sportfish consumption, and catfish and shellfish intake, and negatively associated with income and recent weight loss. Other dietary components collected were not predictive of measured summation operatorPBDE levels. In multivariate models, summation operatorPBDE levels were positively associated with age, years consuming sport fish, shellfish meals, and computer use and negatively associated with recent weight loss. Having summation operatorPBDE levels in the highest quintile was independently associated with older age, male gender, consumption of catfish and shellfish, computer use and spending less time indoors. summation operatorPCB and DDE were strongly associated suggesting common exposure routes. The association between summation operatorPBDE and summation operatorPCB or DDE was much weaker and modeling suggested more diverse PBDE sources with few identified multi-contaminant-shared exposure routes. In our cohort Great Lakes sport fish consumption does not contribute strongly to PBDE exposure.     

Genetic Diversity and Tests of the Hybrid Origin of the Endangered Yellow Larkspur

Abstract: Delphinium luteum ( Ranunculaceae), an endangered larkspur, is restricted to two wild populations near Bodega Bay, California. The total number of individuals in these two populations is estimated to be <100. We used allozyme and random amplified polymorphic DNA ( RAPD) markers to (1) assess levels and patterns of genetic diversity in one wild population and two cultivated populations and (2) test the hypothesis that D. luteum is of hybrid origin between D. decorum and D. nudicaule . These data will be used to aid in developing a management plan to conserve the species. The wild population maintains high levels of genetic diversity. Genetic data indicate that both cultivated populations, especially the north Sonoma population, have several allozymes and RAPD markers not found in the wild population and could be used to establish new populations of D. luteum or to enhance the diversity and size of the wild population. The allozyme data did not reveal any fixed differences between D. decorum and D. nudicaule , although allele frequencies of the putative parental populations differed. At these loci, D. luteum resembled D. nudicaule more than D. decorum  . Many unique RAPD markers distinguish each of the three species. The diagnostic markers from populations of D. nudicaule and D. decorum were not additive in the putative hybrid, and these data indicate that D. luteum is not of recent hybrid origin. Conservation of the yellow larkspur should include strategies that use the cultivated populations of D. luteum , but hybridizing D. decorum and D. nudicaule to "recreate" D. luteum is not recommended.     

Sex differences noted in mercury bioaccumulation in Magicicada cassini

This study focuses on quantitative differences in mercury bioaccumulation based on the sex of the specimen. The species of interest is an herbivorous, terrestrial insect. Male and female periodical cicadas (genus: Magicicada) analyzed using combustion atomic absorption spectrophotometry exhibit different levels of mercury bioaccumulation. The concentration of mercury in Magicicada cassini males was significantly higher than the concentration in females of the same species.     

Statistical Issues for Monitoring Ecological and Natural Resources in the United States

The United States funds a number of national monitoring programs to measure the status and trends of ecological and natural resources. Each of these programs has a unique focus; the scientific objectives are different as are the sample designs. However, individuals and committees, all well aware of the cost of ecological monitoring, have called for more effective monitoring programs. The objective of this paper is to summarize existing programs' statistical designs and discuss potential alternatives for improvement in national monitoring. Can we improve the current situation by providing an overall framework for the design or analysis of data from these disparate surveys? First, the paper summarizes the objectives of these surveys, compares and contrasts their survey designs as currently implemented, and determines what variables they collect. Through this process we identify commonalities and issues that impact our ability to combine information across one or more of the surveys. Three potential alternatives are presented, leading to comprehensive monitoring in the United States.     

Reverse supply chain practices for construction and demolition waste in the Brazilian Amazon: a multi-stakeholder view

Journal of Material Cycles and Waste Management - Construction and demolition waste (CDW) is an environmental problem that affects all regions of the world. Particularly in the Brazilian Amazon...