Unique dataset of a suite of highly carcinogenic toxics in deposited house dust from Malta and USA presented at the 11th Network Conference on Peristent Organic Pollutants (POPs)
Dr Noel Aquilina from the Department of Geosciences was invited by Professor Stuart Harrad, a world-renowned environmental chemist on POPs at the University of Birmingham to present the initial results from collaborative research carried out by the University of Malta (UM), University of Birmingham (UB) and University of California San Francisco (UCSF).
During 2016, at UCSF, Dr Aquilina developed an analytical method to concurrently characterise tobacco smoke and combustion related pollutants in house dust. At UB, Dr Mohamed Abdallah worked on a wide range of POPs and Emerging Flame Retardants (EFRs) in Maltese and Californian house dust. Analysing these trace pollutants required the latest technology and most sensitive analytical instrumentation available in the industry today. The choice of this suite of pollutants was based on the rationale that certain pollutants from tobacco smoke such as NNK and Benzo[a]Pyrene from burning processes are classified as highly carcinogenic to humans (IARC Group 1 carcinogens). The use of FR additives provides scientific challenges in understanding their fate in the environment especially in deciding what materials should be recycled or not. Measuring the levels of the abovementioned toxics is essential to provide a platform to calculate cancer risks by inhalation, ingestion and dermal absorption pathways, especially by children, the most vulnerable category to exposure to pollutants in house dust.
In the 11th Network Conference on POPs held at the University of Birmingham from 25-26th April 2018, Dr Aquilina presented the initial results of the first and unique dataset comparing a very wide range of carcinogenic pollutants found in deposited house dust obtained from Malta and California, USA. The results indicate that although in Malta the house dust should represent a short-term exposure matrix as fitted carpets are rarely used in comparison to the US, the levels of nicotine and tobacco related pollutants are comparable to smoker houses in California, probably due to a higher tobacco prevalence in Malta. By far, pollutants from burning processes were higher in Malta, the most likely sources being indoor burning processes, lack of adequate and efficient ventilation and infiltration of outdoor polluted air. Last but not least, banned POPs such as HBCDs and PBDEs were found in all local samples albeit their levels are lower than in the USA, UK, France and Spain they are comparable to other EU countries such as the Belgium, Czech Republic and Romania. The levels of EFRs cannot be compared as it is one of the very few datasets available worldwide and very little is known about them. Most of the POPs are a cause of concern because they are carcinogenic and bioaccumulate.
Following this pilot study, as Malta is a signatory country of the Stockholm Convention on POPs, it could facilitate the interest of the Environmental Resources Authority (ERA) in monitoring several pollutants listed in the Convention by funding projects at UM intended to characterise better the POPs in our local environment.