World Congress on Risk 2015
19-23 July, 2015, Singapore

Online Program

Session Schedule & Abstracts

* Disclaimer: All presentations represent the views of the authors, and not the organizations that support their research. Please apply the standard disclaimer that any opinions, findings, and conclusions or recommendations in abstracts, posters, and presentations at the meeting are those of the authors and do not necessarily reflect the views of any other organization or agency. Meeting attendees and authors should be aware that this disclaimer is intended to apply to all abstracts contained in this document. Authors who wish to emphasize this disclaimer should do so in their presentation or poster. In an effort to make the abstracts as concise as possible and easy for meeting participants to read, the abstracts have been formatted such that they exclude references to papers, affiliations, and/or funding sources. Authors who wish to provide attendees with this information should do so in their presentation or poster.

Common abbreviations

Tuesday 21-07-2015

Ecological Risk Assessment in Tropical Asia-Pacific and Other Regions of the Pacific Basin, Part II

Room: Breakthrough   15:30–17:00

Chair(s): Jenny Stauber

1    Aerial spraying of herbicides on the Colombia Ecuador border: recognizing the uncertainties in assessing risks. Menzie CA, Exponent (191)

Abstract: The Colombia/Ecuador border region is characterized by rivers and neotropical rainforest. It is also an area where illegal coca plantations have been a source of drugs. An irradiation program consisting of aerial spraying of herbicide was implemented within Colombia in the late 1990s. Ecuadorian residents complained that the spray was impacting their farms and resulting in personal injuries. Diplomatic actions failed between Ecuador and Colombia and the case came before the International Court of Justice. Colombia argued that the claims of harm could not be true because the applications followed strict protocols; their exposure and risk models showed that the complaints could not be valid. Ecuador argued that Colombia\'s risks estimates did not adequately consider the uncertainties and the possibilities of \"black swans\" that may arise if protocols were not always followed. The exposure estimates were highly dependent on the assumptions associated with following protocols related to when and how to apply herbicides. These included plane speed, wind speed, and height off the ground at which spray was released. Departures from those protocols could result in a change in the exposure regime. Arguments over estimates of risk were eventually addressed when Ecuador obtained actual records of aerial spraying applications that showed numerous deviations. The case was settled shortly before it was brought before the justices. From a risk assessment standpoint, the case is a good example of where theoretical risk estimates may not adequately account for real world situations. This talk will cover the ecological, agricultural, and human health risks that were at the center of the controversy.

2    Comparison of tropical and temperate species’ sensitivity to nickel. Wang Z., The University of Hong Kong; Garman E.R.; Schlekat C.E.; Leung K.M.Y. (341)

Abstract: Toxicity data for tropical species are often lacking for derivation of water quality guidelines (WQGs) and for environmental risk assessment (ERA). In order to protect and safeguard valuable natural resources and important biodiversity in tropical aquatic ecosystems, there is a need to obtain more information that is relevant to tropical ecosystems. It is commonly hypothesized that chemical toxicity increases with increasing temperature in aquatic ectothermic organisms. However, previous meta-analysis studies based on limited tropical data indicated that temperate species of both freshwater and saltwater ecosystems tend to be more sensitive to nickel than their tropical counterparts. To further verify such observations, this study aimed to (1) generate more acute toxicity data of Ni for missing taxa like crustaceans and molluscs, and (2) test the null hypothesis that there is no difference in species’ sensitivity toward Ni between temperate and tropical species using a more comprehensive database which contains our new data and other available data extracted from literature. In this presentation, we will describe the new toxicity data of Ni for a number of tropical freshwater and saltwater species. Through construction and comparison of species sensitivity distributions (SSDs) of Ni, we will address if the above null hypothesis is acceptable for freshwater and saltwater ecosystems, respectively. Furthermore, we will explore the influence of data quality on the results of the above comparisons. We will also investigate how temperature can affect the SSDs of Ni for freshwater species as a means to provide some insight on the mechanism of differential sensitivity between temperate and tropical species. Overall, if temperate and tropical toxicity data of Ni can be related in a systematic and predictable way, the former can be used to predict the latter with confidence. Therefore, the findings of this study will have profound implications on the derivation of WQGs of Ni and its management in tropical regions.

3    Ecological impacts of the antimicrobial triclosan on freshwater communities in tropical microcosms. Khatikarn J    (170)

Abstract: Increasing use of triclosan in developing countries, an antimicrobial agent used in personal care products, has led to increasing concentrations of the chemical in wastewater discharged to the environment. Triclosan has been found in rivers receiving wastewater discharge (untreated and treated) in China (2.5-478 ng/L) and Thailand (2.4-9.3 ng/L, and 96 ng/L in the wastewater effluent). Comparison of these measurements with laboratory toxicity data suggest environmental risks in the water and sediment compartments, however actual effects at the population and community levels are still unclear. In this study, the ecological impacts of triclosan on the structure and functioning of tropical freshwater ecosystems were studied by performing a microcosm experiment in Thailand. Triclosan was applied daily for 21 days at concentrations of 0.1, 1, 10, 100 and 300 µg/L to 600-L microcosms. The effects were investigated through the monitoring of four community structural endpoints (i.e., macro-invertebrates, zooplankton, phytoplankton and microorganisms), and two functional endpoints (i.e., organic matter decomposition and nutrient cycling) during a 21-day application period and a 21-day recovery period. Effects of triclosan on the structural endpoints were observed only at high concentrations, as shown by significant shifts in the phytoplanktonic and zooplanktonic communities. Moreover, DNA sequencing of the microbial samples will be used to assess the effects on the relative abundance of several microbial taxonomic and functional groups. The results of this study suggest that environmental concentrations of triclosan found in China and Thailand are not expected to cause direct toxic effects on invertebrate and primary producer communities. However, further studies should focus on assessing the effects of triclosan on microbial community and related ecological functions, especially in the sediment compartment. Keywords: antimicrobial, triclosan, tropics, microcosms, ecological risk assessment

4    Integrated Risk Assessment of Heavy Metals and Organochlorine insecticides in Segara Anakan Lagoon under Indonesian tropical monsoon climates. Noegrohati S    (270)

Abstract: Segara Anakan Lagoon located in southern coast of Java island, Indonesia, protected from the Indian Ocean by Nusakambangan Island. Under tropical monsoon climates, its water dynamics and characteristics are influenced by sea water input during dry season and high input of freshwater in rainy season; bring in suspended sediments including the entrapped pollutants. The largest threat to the ecosystem of Segara Anakan is sedimentation of volcanic debris from mount Galunggung eruption (1982-1984) and run off from poor agricultural practices originated in Citanduy catchment area. Heavy metals such as Cu, Zn, Cd and Hg, also persistent organochlorine insecticides (OCs) used in former malaria eradication program, were detected in samples of dry season 1994. During dry season, sea water enters the lagoon in the spring tide. Upon mixing with saline water, the suspended material in river water was sedimented. In our 2003 studies, during dry season lower level of total suspended solids (<4.5 micrometer) and higher concentration of heavy metal and OCs in sediment were observed. Those entrapped heavy metal and OCs in sediment may serve as pollutant source. High salinity increases the availability of heavy metals due to chloro- and humic material complexation, while salting out effect caused more OCs sedimented. Flesh analysis of bivalves Geloina cf erosa and of detritus eater fish Mugil sp. showed higher concentration of heavy metals and OCs in dry season. Heavy metals were more accumulated in Geloina cf erosa while OCs were more accumulated in Mugil sp. Also plankton density and diversity were higher in dry season than in wet season. Analysis of hair and mother milk samples of local respondent suffering blurred vision showed higher Hg concentrations than blank samples of Glagah coastal area, therefore, risks evaluation of Hg and Cd intake for babies up to 3 month was performed. Assuming the baby\'s weights 5 kg, drink 200 mL/day mother milk, resulting in Cd and Hg intake much higher than FAO/WHO PTWI. Therefore, it is advised that pregnant mothers not to consume seafood from Segara Anakan Lagoon during dry season. Compared to 1994 levels, heavy metals concentrations in sediment and Geloina cf erosa of 2003 were much lower, also sigma DDT concentration in Mugil sp., which demonstrate the flushing effect of fresh water input during rainy season.

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