Measurement of 13C/12C of chloroacetic acids by gas chromatography/combustion/isotope ratio mass spectrometry

This paper describes a novel analytical methodology using gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) to measure the 13C/12C ratios of chloroacetic acids (CAAs). CAAs are a major class of environmental pollutants that are widely distributed throughout the world, often at relatively high concentrations, and are of concern due to their toxic effects, particularly on plants. The 13C/12C of CAA reagents was measured by IRMS subsequent to offline combustion. Aqueous solutions of these CAAs were derivatized to the corresponding methyl chloroacetates (MCAAs) with acidic methanol with a known isotopic composition, extracted into pentane, and analyzed by GC/C/IRMS. Measured 13C/12C ratios of derivatized MCAAs were in agreement with calculated values within 1 per thousand for monochloroacetic acid and trichloroacetic acid and within 2 per thousand for dichloroacetic acid, suggesting that methylation and other analytical methodology steps do not isotopically fractionate derivatized MCAAs. 13C/12C ratios of reagent CAAs from different sources had varying isotopic signatures suggesting differences in source carbon and/or production methods. Our results underscore the potential of stable isotopes to serve as tracers of environmental sources of CAAs.     

Tracking the anthropogenic drivers of ecological impacts

Despite the pivotal role human factors (anthropogenic drivers) are presumed to play in global environmental change, substantial uncertainties and contradictory conclusions about them continue. We attempt to further discipline the human factors issue by estimating the effects of two anthropogenic drivers, population and affluence, on a wide variety of global environmental impacts, including greenhouse gas emissions, emissions of ozone depleting substances, and the ecological footprint. Population proportionately increases all types of impacts examined. Affluence typically increases impacts, but the specific effect depends on the type of impact. These findings refocus attention on population and material affluence as principal threats to sustainability and challenge predictions of an ameliorating effect of rising affluence on impacts.     

Medieval London and its supply hinterlands

The essay reviews the impact of London??s demands for food, drink and fuel on the farming systems and specialisation in the regions from which it drew supplies. Focusing on the well-recorded period around 1,300, when London was a major but second-ranking European city, it makes comparisons with other European cities in the same period and with London in later centuries, as the city developed a world role. Despite its small size by modern standards, medieval London??s impact on its hinterland was distinct, dynamic, highly commercialised and extensive. It shaped rural landscapes and agrarian practices in ways which in key respects conform to modern theories of spatial specialisation. London??s environmental influence operated within an international context, where the opening up of distant resources could affect choices concerning specialisation in and close to the city. Demographic change and shifts in consumption arising from changing standards of living were also influential. This left a marked ??urban footprint?? in production, marketing and the generation of waste. Moreover, its distinctive political context influenced London??s attitude towards managing its supply chains, differentiating it from many of its European counterparts. Medieval observers recognised those landscapes and their connection with the city, but did not theorise them in present-day terms.     

A detailed analysis of musculoskeletal disorder risk factors among Japanese nurses

INTRODUCTION: Although Musculoskeletal Disorders (MSD) represent a common occupational problem, few epidemiological studies have investigated MSD risk factors among Asian nurses, particularly those in Japan. METHOD: We administered a modified Japanese-language version of the Standardized Nordic Questionnaire to 1,162 nurses from a large teaching hospital. MSD categories focused on the neck, shoulder, upper back, and lower back regions. RESULTS: A total of 844 completed questionnaires were analyzed (response rate: 72.6%). The 12-month period-prevalence of MSD at any body site was 85.5%. MSD was most commonly reported at the shoulder (71.9%), followed by the lower back (71.3%), neck (54.7%), and upper back (33.9%). Alcohol consumption, tobacco smoking, and having children were shown to be significant risk factors, with adjusted Odds Ratios of 1.87 (95%CI: 1.17-2.96), 2.45 (95%CI: 1.43-4.35), and 2.53 (95%CI: 1.32-4.91), respectively. Workplace risk factors included manually handling patients (OR: 2.07 to 11.97) and undertaking physically laborious work (OR: 2.09 to 2.76). Nurses reporting pre-menstrual tension were 1.66 and 1.94 times more likely to suffer from lower back and upper back MSD, respectively. High mental pressure was also identified as a significant risk factor for MSD of the neck (OR: 1.53) and shoulder (OR: 2.07). IMPACT ON INDUSTRY: The complex nature of MSD risk factors identified during this study suggests that remediation strategies which focus only on manual handling tasks would probably be suboptimal in reducing MSD among nurses. Therefore, to help alleviate their considerable MSD burden, a greater emphasis will need to be placed on job satisfaction, work organization, and occupational stress, as well as the more traditional hazard reduction strategies such as manual handling, work tasks, and other occupational factors.     

Levels and trends of brominated flame retardants in the Arctic

Polybrominated diphenyl ethers (PBDEs) containing two to seven bromines are ubiquitous in Arctic biotic and abiotic samples (from zooplankton to polar bears (Ursus maritimus) and humans; air, soil, sediments). The fully brominated decabromodiphenyl ether (BDE-209), hexabromocyclododecane (HBCD), tetrabromobisphenol A (TBBPA) and polybrominated biphenyls (PBBs) are also present in biotic and abiotic samples. Spatial trends of PBDEs and HBCD in top predators are similar to those seen for polychlorinated biphenyls (PCBs) and indicate western Europe and eastern North America as source regions. Concentrations of tetra- to heptaBDEs have increased significantly in North American and Greenlandic Arctic biota and in Greenland freshwater sediments paralleling trends seen further south. For BDE-209, increasing concentrations in Greenlandic peregrine falcons (Falco peregrinus) and in dated lake sediment cores in the Canadian Arctic have been seen during the 1990s. BDE-47, -99, -100 and -153 are observed to biomagnify in Arctic food webs. summation operatorPBDE concentrations in Arctic samples are lower than in similar sample types from more southerly regions and are one or more orders of magnitude lower than summation operatorPCB concentrations except for some levels for air. Air and harbor sediment results for PBDEs indicate that there are local sources near highly populated areas within the Arctic. Findings of PBBs on moss and TBBPA on an air filter, and that both are found in biota at high trophic levels indicates that these compounds may also reach the Arctic by long-range atmospheric transport. Based on the evidence of their presence in the Arctic and indications that most if not all are undergoing long-range transport, these brominated flame retardants (BFRs) have characteristics that qualify them as POPs according to the Stockholm Convention.     

Distribution and transportability of hexabromocyclododecane (HBCD) in the Asia-Pacific region using skipjack tuna as a bioindicator

The geographical distribution of hexabromocyclododecane (HBCD) was investigated through analysis of muscle tissue of skipjack tuna (Katsuwonus pelamis) collected from offshore waters of Asia-Pacific region (Japan, Taiwan, Philippines, Indonesia, Seychelles, Brazil, Japan Sea, East China Sea, South China Sea, Indian Ocean and North Pacific Ocean). HBCD was detected in almost all samples analyzed (<0.1 to 45 ng/g lipid weight basis), indicating widespread presence of this compound in the marine environment. Elevated concentrations of HBCD were found in skipjack tuna from areas around Japan, which have the larger modern industrial/urban societies, and implicated these areas as primary regional sources. All three individual HBCD isomers (alpha-, gamma- and beta-HBCD) were detected in almost all samples; the percentage contribution of the alpha-isomer to total HBCD increased with increasing latitude. The estimated empirical 1/2 distance for alpha-HBCD was 8500 km, which is one of the highest atmospheric transportability among various halogenated persistent organic pollutants (POPs).     

MODELING MULTIPLE-USE IN NATURAL AREAS: PART II - THE SANTEE SWAMP STUDY1

ABSTRACT: The previous paper in this two-part series presented the basic information of a newly developed mathematical model of multiple-use in natural areas. The model is a unified system for the assessment of cases where development is proposed for relatively natural areas. This paper presents the results of an application of the model to a study of the proposed timber harvest in the Great Santec Swamp in South Carolina. This was done in an effort to demonstrate the utility of the model as a planning and assessment tool. Four potential uses of the Swamp were investigated: logging of hardwood saw timber, hunting, fishing, and nature observation. The model system proved to be extremely useful in the evaluation of potential management schemes and in the selection of the most promising or optimal management plan.     

REVIVING URBAN STREAMS: LAND USE,HYDROLOGY, BIOLOGY,AND HUMAN BEHAVIOR1

ABSTRACT: Successful stream rehabilitation requires a shift from narrow analysis and management to integrated understanding of the links between human actions and changing river health. At study sites in the Puget Sound lowlands of western Washington State, landscape, hydrological, and biological conditions were evaluated for streams flowing through watersheds with varying levels of urban development. At all spatial scales, stream biological condition measured by the benthic index of biological integrity (B‐IBI) declined as impervious area increased. Impervious area alone, however, is a flawed surrogate of river health. Hydrologic metrics that reflect chronic altered streamflows, for example, provide a direct mechanistic link between the changes associated with urban development and declines in stream biological condition. These measures provide a more sensitive understanding of stream basin response to urban development than do treatment of each increment of impervious area equally. Land use in residential backyards adjacent to streams also heavily influences stream condition. Successful stream rehabilitation thus requires coordinated diagnosis of the causes of degradation and integrative management to treat the range of ecological stressors within each urban area, and it depends on remedies appropriate at scales from backyards to regional storm water systems.