Spatial and Temporal Variations in Trace Metal Concentrations in the Cockle, Austrovenus Stutchburyi from Otago, New Zealand

This is the first comprehensive study of sources of variation in metal concentrations within the whole tissues of a shallow burrowing, filter-feeding intertidal clam, Austrovenus stutchburyi. Samples were collected from 12 sites in April, August, November and February in 1993–1994 in the vicinity of Otago Harbour and Peninsula, New Zealand. Total tissue trace metal concentrations (μg g⁻¹ dry weight) were measured in individual animals for the essential metals : Mn, Cu, Zn, Ni and the non-essential Cr using trace-metal clean acid-digestion and ICP-OAES techniques. Average metal concentrations were 3–60 μg g⁻¹ for Cu, 40–118 μg g⁻¹ for Zn, 2–12 μg g⁻¹ for Mn, 5–35 μg g⁻¹ for Ni and 1–44 μg g⁻¹ for Cr. These levels decreased with body weight and differed amongst sites except for Cr in February (mid-summer). Highest concentrations occurred at sites close to a city (Dunedin) and within the central harbour region although the Cu, Zn, Ni and Cr concentrations did not correlate with the environmental gradient or season. At one coastal site, samples of both the blue mussel Mytilus galloprovincialis and cockles gave similar trends in trace metal levels. These results suggest that the cockle could be a useful trace metal biomonitor within NZ estuaries.     

Disposal practices for unused medications around the world

Pharmaceuticals have been detected throughout the environment where at least in some cases, they have been shown to have a detrimental effect. Many result from improper patient disposal of unused pharmaceuticals via environmentally-unfriendly routes, such as the sink, toilet or rubbish bin. This review surveys the current peer-reviewed literature on attitudes and practices to medicine disposal methods as reported by patients and the various medication disposal and destruction systems around the world. A literature search was carried out using the keywords 'medicines disposal', 'unused medicines', 'medicines wastage', and 'medication disposal' in the PubMed TM, ISI Web of Knowledge TM, Google Scholar TM, Medline TM, Scopus TM and International Pharmaceuticals Abstracts TM up to the end of May 2010. Twelve peer-reviewed articles with specified sample sizes were selected. The most popular methods for medication disposal were in the garbage, toilet or sink. Liquid medications were more likely to be rinsed down the sink, as opposed to solid tablets and capsules which were more likely deposited in the rubbish bin. Much confusion exists about the 'proper' way of medication disposal as many countries do not have standard medication disposal protocols. Furthermore, some pharmacies around the world refused to accept unused medications or discouraged the practice. Patients with knowledge about the impact of pharmaceuticals in the environment were more likely to return medications for proper disposal and destruction. It is concluded that it is of paramount importance that a formalized protocol for patient disposal and destruction of pharmaceuticals be implemented around the world.     

Disposal practices for unused medications in New Zealand

BackgroundThere is an enhanced international awareness that the improper disposal of unwanted and unused medications may have a detrimental effect on the environment.ObjectivesThe aim of this study was to determine the proportion of unused medications in New Zealand that are not returned to a pharmacy for disposal and are instead disposed of via land fill or water systems. In addition, this study intended to identify why these medications were unused or unwanted.DesignAn online survey was placed on the New Zealand National Poisons Centre website for a period of three months during 2008. This consisted of a series of questions with predefined answer sets and asked about collection of medications, why there may be unused medications, storage of medications and disposal of medications.ResultsThis survey was completed by 452 individuals. 62% of respondents currently had unwanted medications in their house. The most common reason for people to have leftover medication was ‘medical condition improved or resolved’ (n = 307). Depending on formulation type, between 13–24% of unused medications were returned to pharmacies with tablets and capsules being most likely to be returned and liquids most likely to be added to water systems.ConclusionsA significant percentage of unwanted medications are disposed of via routes that have the potential to adversely affect the environment. Reducing excess medications and wastage as well as education of appropriate disposal techniques may minimize their potential impact on the environment.     

The use of carbon and nitrogen isotope ratios to identify landfill leachate contamination: Green Island Landfill, Dunedin, New Zealand

A study was undertaken to determine whether the isotopic ratios of C and N could be used to uniquely identify municipal solid waste landfill leachate as a source of contamination in the Kaikorai Estuary, Dunedin, New Zealand. Leachate samples were taken from the adjacent Green Island Landfill (GILF), and surface water samples were collected over an 8-month period from the stream and estuary, upstream and downstream of the landfill. Samples were analysed for delta(13)C-dissolved inorganic carbon (DIC), delta(15)N-NO(3)(-), delta(15)N-NH(4)(+), and particulate organic matter (POM) delta(13)C and delta(15)N. Plant material collected along the Kaikorai Stream was analysed for POM delta(13)C and delta(15)N. Leachate was found to have a distinct isotopic signature characterised by a highly enriched delta(13)C-DIC (as much as 16.11+/-0.23 per thousand ) and highly enriched delta(15)N-NH(4)(+) (as much as 27.42+/-0.90 per thousand ). Evidence of leachate contamination was found in the isotopic signatures of downstream delta(13)C-DIC, delta(15)N-NH(4)(+), and delta(13)C and delta(15)N of plant material POM. Other potential sources of enriched delta(13)C-DIC and delta(15)N-NH(4)(+) present in the study area, such as estuarine waters and livestock effluent, were eliminated on the basis of their isotopic characteristics.