Stratospheric ozone,global warming,and the principle of unintended consequences—An ongoing science and policy story

Supplemental Materials: Supplemental materials are available for this paper. Go to the publisher's online edition of the Journal of the Air & Waste Management Association.      

Persistence of TBT and copper in excess on leisure boat hulls around the Baltic Sea

A handheld XRF-analyzer specially calibrated for measurements of metals on plastic boat hulls has been used on leisure boats in Denmark (DK), Finland (FI), and Germany (DE). The results on tin and copper are presented as μg metal/cm². Tin is a proxy for the occurrence of organotin compounds on the boat. Two or three sites were visited in each country and between 25 and 90 boats were measured at each site. Every boat was measured at six to eight places, and the results are presented both as mean and median values. Linear regression of mean to median values of the 377 data pairs shows high relationship with R²?=?0.9566 for tin and R² of 0.9724 for copper and thus both ways of calculation may be used. However, for regulative use, it is suggested that all individual measurements on each boat should be presented and used for decisions of removal or sealing of boat hulls. The results are compared with published data from different parts of Sweden, i.e., boats in fresh water, brackish water, and salt water. The results show that tin with mean values >?50 μg Sn/cm² is still found on 42, 24, and 23% of the boats in DK, FI, and DE, respectively. The corresponding percentages based on median values are 38, 22, and 18% for DK, FI, and DE, respectively. The variation among boats is high with a maximum mean value of 2000 μg Sn/cm². As comparison, one layer of an old TBT antifouling paint Hempels Hard racing superior, corresponds to 300 μg Sn/cm². The percentage of boats with tin >?400 μg Sn/cm² content based on mean values was 10% in DK, 5% in FI, and 1% in DE. The corresponding median values were 9, 6, and 1% for DK, FI, and DE. Copper, >?100 μg Cu/cm², was detected on all measured boats in DK and in DE and on all but 3% of the FI boats. One layer of Hempels MilleXtra corresponds to ? 4000 μg Cu/cm². The recommendation on the can is to apply two layers. The proportion of boats with higher mean copper values than 8000 μg Cu/cm² was 51, 56, and 61 for boats in DK, FI, and DE, respectively. The proportion based on median values >?8000 μg Cu/cm² was 50, 54, and 61% for DK, FI, and DE. The conclusion is that many leisure boats around the Baltic Sea still display or possess antifouling paints containing organotin compounds and that more than half of the boats have more copper than needed for one boat season according to the paint producers. Much of these known toxic compounds will probably be released into the environment and harm the biota. The calibrated XRF-method, intended for area measurements on boat hulls, is an easy and cheap way to detect boats with organotin compounds and high copper content. We recommend environmental authorities to use this method for identification of such boats and to use the results for requesting measures to minimize further leakage to the environment.

     

Cadmium in sewage sludge in a Swedish region: sources and reduction opportunities

To create a more sustainable future, one of the Swedish government's aims is to close the eco-cycles between urban consumption areas and arable land. Increasing the use of sewage sludge from municipal wastewater treatment plants (MWTPs) is one method of achieving this goal. However, the use of sewage sludge is often prohibited due to its high concentrations of cadmium. As a consequence, large amounts of sewage sludge are deposited each year in landfills. This disposal has become more expensive for local authorities due to a new deposit tax introduced in the year 2000. Based on a survey of cadmium sources to MWTPs in a Swedish region this paper focuses on opportunities local authorities in Sweden have to influence the occurrence of cadmium in the sewage sludge. The results from the study show that cadmium in sewage sludge originates from diffuse sources, which are hard for local authorities to influence by direct means. This is most obvious for sources of cadmium in wastewater from households, which causes about one-third of the inflow of cadmium to MWTPs. Thus, the local authorities' possibilities are, in general, still restricted to downstream actions (such as disconnecting identified industrial sources and reconstructing the sewage system to further separate collection of wastewater and storm water). Local authorities could also implement changes in the process at the MWTP or an extended treatment of the sewage sludge generated. Nonetheless, these possible measures do not provide a sustainable solution to the cadmium issue since the origins of the sources remain. Hence, long-term strategies - outside of the scope of local authorities - need to focus on a general decrease of cadmium in society. However, increased knowledge about the distribution among different sources of cadmium to MWTPs may encourage local authorities to establish priorities for measures that will improve the quality of the sewage sludge.     

Improvement of Air Quality in a Small Indoor Ice Arena by Effective Emission Control in Ice Resurfacers

ABSTRACT

The effectiveness of a new emission control system in the ice resurfacer was tested in an exhaust gas emission laboratory, and the improvement of the air quality in a small, enclosed ice arena was demonstrated in a 4.5-month follow-up study. The emission control system consisted of a lambda sensor-controlled fuel supply and a three-way metallic catalyst that were applied to a propane-fueled resurfacer. In the laboratory tests, the engine emissions of carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NO ) reduced simultaneously by 91, 90, and 96%, respectively. During the air quality follow-up the median 1-hour average nitrogen dioxide (N0₂) concentration inside the ice arena decreased from 430 ug/m³ (230ppb) to 58 ug/m³ (31 ppb), and that of CO decreased from 4.4 mg/m³ (3.8 ppm) to 1.5 mg/m³ (1.3 ppm). The new emission control system proved to be a feasible, reliable, and effective means to improve the indoor air quality in the ice arena. However, continuous mechanical ventilation was necessary during all business hours in order to achieve and maintain a fully acceptable air quality with this technology.     

Sustainable Development by Design: Review of Life Cycle Design and Related Approaches

Abstract

The quality of stationary source emission factors is typically described using data quality ratings, which provide no quantification of the precision of the emission factor for an average source, nor of the variability from one source to another within a category. Variability refers to actual differences caused by differences in feedstock composition, design, maintenance, and operation. Uncertainty refers to lack of knowledge regarding the true emissions. A general methodology for the quantification of variability and uncertainty in emission factors, activity factors, and emission inventories (EIs) is described, featuring the use of bootstrap simulation and related techniques. The methodology is demonstrated via a case study for a selected example of NO_x emissions from coal-fired power plants. A prototype software tool was developed to implement the methodology. The range of interunit variability in selected activity and emission factors was shown to be as much as a factor of 4, and the range of uncertainty in mean emissions is shown to depend on the interunit variability and sample size. The uncertainty in the total inventory of ?16 to +19% was attributed primarily to one technology group, suggesting priorities for collecting data and improving the inventory. The implications for decision-making are discussed.     

Sources of heavy metal contamination in Swedish wood waste used for combustion

In this paper, wood waste (RWW) recovered for heat production in Sweden was studied. Previous research has concluded that RWW contains elevated amounts of heavy metals, causing environmental problems during waste management. This study extends previous work on RWW by analysing which pollution sources cause this contamination. Using existing data on the metal contents in various materials, and the amounts of these materials in RWW, the share of the elevated amounts of metals in RWW that these materials explain was quantified. Six different materials occurring in RWW were studied and the results show that they explain from 70% to 100% of the amounts of arsenic, chromium, lead, copper and zinc in RWW. The most important materials contributing to contamination of RWW are surface-treated wood, industrial preservative-treated wood, plastic and galvanised fastening systems. These findings enable the development and evaluation of strategies aiming to decrease pollution and resource loss from handling RWW. It is argued that source separation and measures taken further downstream from the generation site, such as treatment, need to be combined to substantially decrease the amount of heavy metals in RWW.