Methylmercury in a predatory fish (Cichla spp.) inhabiting the Brazilian Amazon

This research tested whether limnological conditions, biological characteristics of fish and anthropogenic impacts influenced the assimilation of methylmercury into the muscle of a sedentary piscivorous fish, Cichla spp., from three rivers (Negro, Madeira, Tapajós) and two hydroelectric reservoirs (Balbina, Tucuruí) within the Brazilian Amazon. Methylmercury in this fish ranged from 0.04 to 1.43microgg(-1) w.w. across sites. No significant differences were observed in the methylmercury concentrations between males and females, or for different morphotypes of this species. Positive correlations were found between methylmercury and fish body weight. No differences were found between the weight normalized methylmercury (MeHg) concentrations or its percent of total mercury in fish from the three rivers; weight normalized MeHg was highest in one of the two reservoirs. In Rio Tapajós, where gold mining and deforestation cause high water turbidity, fish showed the highest MeHg and concentrations were different across the four sites examined. In all sampling areas, the %MeHg was found to be higher than 70.     

Bystander injury evaluation of children from midwestern agricultural operations

Background

With more than a million youth living on agricultural operations, it is important for parents to understand the consequences of bystander injuries that children experience in these environments. We identified the childhood injuries for bystander status and compared the severity of these injuries to the working children in the Regional Rural Injury Study-II (RRIS-II).

Methods

RRIS-II followed 16,546 children (∼ 85% of eligible) from rural communities in the Midwest for two six-month recall periods in 1999 and 2001. Demographic, injury, and exposure data were collected through comprehensive computer-assisted telephone interviews. Child injuries were cataloged using narrative scenarios into four categories: (a) directly work-related; (b) indirectly work-related; (c) non-working accomplice; and (d) non-working attendant; the latter three all being bystander categories. Poisson regression modeling was used to calculate rates of bystander injuries. Frequencies were used for comparison of severity measures.

Results

Among the 463 child injuries (aged < 20 yrs), 102 were bystander injuries. Of the bystander-related injuries, 14 were identified as indirectly work-related (working bystanders), 27 as non-working accomplice (passengers/tag-alongs), and 60 as non-working attendant (playing on the operation). The overall rate of bystander injuries was 6.4 per 1,000 people, 95% CI (5.0, 8.1). Males, compared with females, had more than twice the injury rate (8.7; 95% CI 6.4-11.8, and 3.9; 95% CI 2.7-5.7, per 1,000 people, respectively). Bystanders in this population had more severe injuries with 4% having life-threatening circumstances; of these, 4% of the accomplices and 2% of the attendants subsequently died.

Conclusions

Children who live or work on agricultural operations are vulnerable to many hazards. Therefore, this study examined child injuries and found a clear difference in the consequences of these injuries between working-related and bystanding-related injuries.

Impact on Industry

Unlike occupations such as construction and mining, where laws and organizations have been created for the protection of bystanders, agricultural bystanders have remained unprotected and have had to face the consequent injury and death outcomes. As public health professionals considering these risks, it is necessary that we work to develop more intervention studies and continue to propose suggestive guidelines for child safety in these environments so as to challenge family traditions and possibly spark public policies that will give further protection to this population.     

Strengthening road safety strategy development ‘Towards Zero’ 2008–2020 – Western Australia’s experience scientific research on road safety management SWOV workshop 16 and 17 November 2009

With a significant list of achievements in traffic safety over some 40 years, Australia’s most successful initiatives have emerged from consideration of the scientific basis for achieving effective results. Over time, the increasing use of scientific methods has matured to an extent whereby road safety strategies for entire jurisdictions are now being formed and optimised on the basis of evidence-based mathematical modelling of predicted strategy performance over periods of ten or more years ahead. This paper describes the approach used in the State of Western Australia (WA) to support the development of its new strategy, ‘Towards Zero’, addressing the 12-year period from 2008 to 2020. Also described is the early development of the modelling approach in the State of Victoria, Australia, subsequently applied, refined and adapted to Western Australia. The ‘Towards Zero’ strategy aims to ensure that road safety policies continue to evolve within a strategic framework, based on Australasia’s Safe System framework, which was derived from the best elements of the Swedish Vision Zero and the Dutch Sustainable Safety visions.The process for the development of the strategy involved a greater degree of community and stakeholder engagement than has been the case previously, based on the fundamental belief that the community should be provided with the best evidence about what works no matter how controversial, so that it can debate and consider the options available to improve safety.It is equally important to have a strategy based on the best possible evidence. The Monash University Accident Research Centre (MUARC) was appointed by the WA Office of Road Safety to identify, describe and recommend proven counter-measures within the Safe System framework and develop a series of scientifically sound directions and options.This paper outlines the modelling technique used by MUARC along with results and summarises the community consultation process.     

Evaluation of Four Live-Sorting Methods for Use in Rapid Biological Assessments Using Macroinvertebrates

Rapid bioassessment (RBA) techniques for evaluating river health are now commonplace and there is much debate on the best methods that should be used. One of the important features of RBA is subsampling of large qualitative or semi-quantitative samples to reduce the costs associated with handling and identifying animals. In Australia, the Australian River Assessment System (known as “AusRivAS”) has been widely used since 1994 to monitor and assess river health. To test the efficacy of AusRivAS protocols, four live-sorting protocols, the standard Australian River Assessment Scheme (AusRivAS) and three suggested improvements, were evaluated in three habitat types and in clear and turbid rivers. The suggested improvements included using magnification during the live-sort process, separate sorting of coarse and fine fractions and increasing the amount of time or animals collected. There was no statistically significant difference between any of the trialed live-sort protocols in terms of the number of taxa collected compared to the number remaining, the community composition, the abundances of individual families collected, or the AusRivAS Observed/Expected taxa ratios. The lack of differences between the live-sort protocols suggests that technicians using the current standard AusRivAS protocols are able to effectively obtain a representative subsample of animals from the whole kick or sweep net qualitative sample. This has the advantage of cost savings because no retraining will be required, field procedures will remain uncomplicated and previous river health assessments will remain valid.     

A comparison of portable XRF and ICP-OES analysis for lead on air filter samples from a lead ore concentrator mill and a lead-acid battery recycler

Personal and area samples for airborne lead were taken at a lead mine concentrator mill, and at a lead-acid battery recycler. Lead is mined as its sulfidic ore, galena, which is often associated with zinc and silver. The ore typically is concentrated, and partially separated, on site by crushing and differential froth flotation of the ore minerals before being sent to a primary smelter. Besides lead, zinc and iron are also present in the airborne dusts, together with insignificant levels of copper and silver, and, in one area, manganese. The disposal of used lead-acid batteries presents environmental issues, and is also a waste of recoverable materials. Recycling operations allow for the recovery of lead, which can then be sold back to battery manufacturers to form a closed loop. At the recycling facility lead is the chief airborne metal, together with minor antimony and tin, but several other metals are generally present in much smaller quantities, including copper, chromium, manganese and cadmium. Samplers used in these studies included the closed-face 37 mm filter cassette (the current US standard method for lead sampling), the 37 mm GSP or "cone" sampler, the 25 mm Institute of Occupational Medicine (IOM) inhalable sampler, the 25 mm Button sampler, and the open-face 25 mm cassette. Mixed cellulose-ester filters were used in all samplers. The filters were analyzed after sampling for their content of the various metals, particularly lead, that could be analyzed by the specific portable X-ray fluorescence (XRF) analyzer under study, and then were extracted with acid and analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES). The 25 mm filters were analyzed using a single XRF reading, while three readings on different parts of the filter were taken from the 37 mm filters. For lead at the mine concentrate mill, all five samplers gave good correlations (r2 > 0.96) between the two analytical methods over the entire range of found lead mass, which encompassed the permissible exposure limit of 150 mg m(-3) enforced in the USA by the Mine Safety and Health Administration (MSHA). Linear regression on the results from most samplers gave almost 1 ratio 1 correlations without additional correction, indicating an absence of matrix effects from the presence of iron and zinc in the samples. An approximately 10% negative bias was found for the slope of the Button sampler regression, in line with other studies, but it did not significantly affect the accuracy as all XRF results from this sampler were within 20% of the corresponding ICP values. As in previous studies, the best results were obtained with the GSP sampler using the average of three readings, with all XRF results within 20% of the corresponding ICP values and a slope close to 1 (0.99). Greater than 95% of XRF results were within 20% of the corresponding ICP values for the closed-face 37 mm cassette using the OSHA algorithm, and the IOM sampler using a sample area of 3.46 cm2. As in previous studies, considerable material was found on the interior walls of all samplers that possess an internal surface for deposition, at approximately the same proportion for all samplers. At the lead-acid battery recycler all five samplers in their optimal configurations gave good correlations (r2 > 0.92) between the two analytical methods over the entire range of found lead mass, which included the permissible exposure limit enforced in the USA by the Occupational Safety and Health Administration (OSHA). Linear regression on the results from most samplers gave almost 1 ratio 1 correlations (except for the Button sampler), indicating an absence of matrix effects from the presence of the smaller quantities of the other metals in the samples. A negative bias was found for the slope of the button sampler regression, in line with other studies. Even though very high concentrations of lead were encountered (up to almost 6 mg m(-3)) no saturation of the detector was observed. Most samplers performed well, with >90% of XRF results within +/- 25% of the corresponding ICP results for the optimum configurations. The OSHA algorithm for the CFC worked best without including the back-up pad with the filter.     

Managing an Endangered Asian Bovid in an Australian National Park: The Role and Limitations of Ecological-Economic Models in Decision-Making

Should north Australia’s extensive populations of feral animals be eradicated for conservation, or exploited as a rare opportunity for Indigenous enterprise in remote regions? We examine options for a herd of banteng, a cattle species endangered in its native Asian range but abundant in Garig Gunak Barlu National Park, an Aboriginal land managed jointly by traditional owners and a conservation agency in the Northern Territory of Australia. We reflect on the paradoxes that arise when trying to deal effectively with such complex and contested issues in natural resource management using decision-support tools (ecological-economic models), by identifying the trade-offs inherent in protecting values whilst also providing incomes for Indigenous landowners.     

A comparison of mussels (Perna viridis) and semi-permeable membrane devices (SPMDs) for monitoring chlorinated trace organic contaminants in Hong Kong coastal waters.

A comparison of mussels (Perna viridis) and semi-permeable membrane devices (SPMDs) was carried out at five sites, representing a gradient of contaminant concentrations, in Hong Kong coastal waters. Mussels, originally collected from a “clean” location, were deployed along with SPMDs at each site for 30 days. Analyses for chlorinated pesticides and polychlorinated biphenyls (PCBs) indicated that SPMDs have potential as monitoring tools, and to some extent can overcome the problems associated with mussels, such as natural variability, differing age, sex, and physical condition. However, in most cases, SPMDs failed to rank the sites in the same order as mussels in terms of contaminant concentrations. Nonetheless, in localities where mussels cannot survive – as shown at Kwun Tong in the present experiment – SPMDs may be valuable in providing an indication of potentially bio-available lipophilic pollutants.     

Hierarchical regulation of nitrogen export from urban catchments: interactions of storms and landscapes.

In urban catchments of arid central Arizona, we investigate how the export of mineral and organic nitrogen (N) in storm runoff is regulated by interactions between local landscape characteristics and broader scale storm features. First, we test whether N export is more a function of (1) processes that affect N concentration in runoff or (2) the propensity of the catchment to convey rainfall as runoff. With data pooled across catchments, the mass of N in export (load) is determined by processes regulating runoff N concentration. There are exceptions when catchments are examined individually, where N load from some catchments is determined by the hydrologic responsiveness of the catchment. Second, we investigate the relationship between N export and catchment features. Loads per catchment area were greater from more impervious catchments, probably because impervious catchments held more N in a mobilizable phase and conveyed more rainfall as overland flow. Loads per area were lower from larger catchments, possibly owing to more N-retention hot spots in larger catchments. Catchments with the greatest N exports were those with commercial land use, and loads decreased as development became less prevalent or as residential replaced industrial land use. Third, we investigated how catchment features moderated direct responses of N export to storms. Export was less correlated with storm features in catchments that were larger, more pervious, and less industrial. Results support an "N build and flush" hypothesis, which purports that there is little biotic processing of N deposited to arid, urban surfaces with little organic matter. The rate and duration of deposition determine the size of the mobile N pool. Any amount of rainfall capable of generating overland flow would entrain nearly all mobilizable N and export it from the catchment. Nonetheless, these results suggest that, even with daunting seasonal and interannual variability in storm conditions, material export can be reduced by managing intrinsic catchment features.     

WATERSHED SCALING EFFECT ON BASE FLOW NITRATE,VALLEY AND RIDGE PHYSIOGRAPHIC PROVINCE1

ABSTRACT: A study of stream base flow and NO₃‐N concentration was conducted simultaneously in 51 subwatersheds within the 116‐square‐kilometer watershed of East Mahantango Creek near Klingerstown, Pennsylvania. The study was designed to test whether measurable results of processes and observations within the smaller watersheds were similar to or transferable to a larger scale. Ancillary data on land use were available for the small and large watersheds. Although the source of land‐use data was different for the small and large watersheds, comparisons showed that the differences in the two land‐use data sources were minimal. A land use‐based water‐quality model developed for the small‐scale 7.3‐square‐kilometer watershed for a previous study accurately predicted NO₃‐N concentrations from sampling in the same watershed. The water‐quality model was modified and, using the imagery‐based land use, was found to accurately predict NO₃‐N concentrations in the subwatersheds of the large‐scale 116‐square‐kilometer watershed as well. Because the model accurately predicts NO₃‐N concentrations at small and large scales, it is likely that in second‐order streams and higher, discharge of water and NO₃‐N is dominated by flow from smaller first‐order streams, and the contribution of ground‐water discharge to higher order streams is minimal at the large scale.