Environmental forensic evidence from perchlorate in dust fall

Summer in Malta is accompanied by fireworks as part of the numerous (about 85) religious festivals (festa) that occur throughout the period. We attempted to establish whether firework activity is truly following official trade statistics, which imply a decreasing trend, or otherwise. Firework manufacture critically depends on the availability of oxidising agents, two of which (KNO3, KClO3) being controlled by permits but not potassium perchlorate (KClO4) which is freely available. Recent changes in legislation have slightly decreased the quantity of KClO3 and increased that of KNO3 and according to official trade statistics, consumption of KClO4 has decreased from 17 t/a in 2010 to ≈ 2.5 t/a during 2011--2014. However, from levels of perchlorate in dust fall and rate of total deposition we calculated the quantity of KClO4 used during 2012 and obtained ≥ 90 t/a, 36 times the official figure. This situation is serious since the danger of accidental explosion during manufacture escalates as production intensifies. Also, contamination of the environment by firework-waste appears destined to remain high with possible consequent effects on human health.peer-reviewe

Perchlorate contamination of soils collected from the Maltese Islands

During the summer months, the Maltese Islands experience a large number of religious feasts, most of which are accompanied by firework activity. Between the 26th of January and the 8th of December, approximately 86 religious feasts are celebrated annually in different towns and villages in the Maltese Islands, accompanied by both aerial and ground fireworks displays. The pyrotechnical community counts several thousand enthusiasts who passionately and without any financial compensation produce fireworks. Perchlorate contamination in the environment is a worldwide problem, with high levels detected in dust fall collected from the Maltese Islands (Vella et al., 2015). During this study the levels of perchlorate in soil samples collected from 19 different locations were determined. Perchlorate was detected in 8 of 19 samples, with 3 of these samples having levels below detection limit. The levels ranged from BDL to 357 μg kg-1, with a mean value of 49.9 μg kg-1. The highest perchlorate concentrations were detected in soils collected from the South of the Maltese Islands, as was observed for dust samples. This was attributed to the predominant wind direction, being from the Northwest, causing the movement of contaminants from the North to the South of the Maltese Islands. These results and perchlorate levels in dust fall (Vella et al., 2015), clearly point out that the Maltese environment is contaminated with perchlorate, due to the excessive pyrotechnic activity.peer-reviewe

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe