Contamination of outdoor settled dust by butyltins in Malta

Abstract

The presence of compounds of tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) was determined in outdoor settled dust collected from several sites on the island of Malta, mainly from flat rooftops of school buildings. The dust was separated into three size fractions with diameters (µm) >250, 125-250 and <125, and the two finer fractions were analysed for butyltins using extraction with glacial acetic acid followed by derivatization/solvent extraction with sodium tetraethylborate in the presence of iso-octane and quantitation by gas chromatography with flame photometric detection. The presence of TBT, DBT and MBT was established in most of the samples and TBT concentrations varied from non-detectable (<5 ng Sn g −1 ) to highs of 15.5 and 18.7 µg Sn g −1 in Senglea and Marsaxlokk. TBT was generally found at concentrations significantly higher than reported hitherto in house dust collected from European homes. The geographical distribution of total organotins in both dust fractions suggests that TBT originates mainly from antifouling marine paint residues which contaminate the urban environment when ships' hulls are sand-or hydro-blasted during maintenance and repair at the drydocks facility in Grand Harbour. Other significant sources of TBT are located at Marsaxlokk fishing port and Wied iż-Żurrieq creek, both hosting sizeable communities of fishermen and leisure boating. The data also suggest that the municipal solid waste landfill at Maghtab is an inland source of butyltins. We suggest that dust containing harmful butyltins could possibly be ingested to expose humans to a risk which is probably of concern especially for young children living close to the hotspots of contamination.

Pleasure Boatyard Soils are Often Highly Contaminated

“…In water, concentrations of 0.0002 μg/l (Directive 2008/105/EC) are considered to be safe, and for the sediment, the proposed safe value is 0.02 μg/kg DW (Environmental Quality Standards (EQS) 2005 ). The high concentrations found in the boatyards in this and other studies (Decelis and Vella 2007 ) emphasize the need for EQS standards for these substances both in sediment and soil.…”

“…Dust and fine eroded particles from antifouling paint can travel relatively long distances. Turner 2010 and the references therein and several reports show high levels of TBT contamination in nearby environments (Decelis and Vella 2007 ). In one case in Thailand, elevated lead levels were found in dust from a boatyard several hundred meters from the boatyard (Maharachpong et al 2006 ).…”

“…Although most of the substances found at high concentrations in boatyards have been restricted or forbidden for a long time, the data show that these substances are still found in the soil and in the environment (e.g., Decelis and Vella 2007 ; Strand et al 2003 ; Eklund et al 2008 , 2010 ; Turner 2010 and references therein).…”

Paint particles in the marine environment: An overlooked component of microplastics

“…Paint particles from these sources are transported to the aquatic environment as airborne particulates that are subject to fallout, with road runoff or treated waste water, or via washdown from boat maintenance facilities or coastal structures undergoing repair. The significance of the local transport of airborne paint particles has been established from the levels and signatures of contamination of soils and roof top dusts of residential and municipal buildings in the vicinity of roads, dry docks, boatyards and harbours ( Decelis and Vella, 2007 ; Jartun et al., 2009 ; Turner, 2013 ; Eklund et al., 2014 ; Sakata et al., 2017 ; Meza-Figueroa et al., 2018 ). Given the particle size range generated by sanding (in the range of < 50 nm to a few μm in diameter; Koponen et al., 2009 ), however, the potential range of airborne transport of paint particles is considerable.…”

Contamination of a boatyard for maintenance of pleasure boats

“…Spread of TBT from boat repair activities was determined in dust collected from rooftops of houses at Malta (Decelis and Vella 2007), which suggested that dust from boat maintenance areas can have impact on adjacent terrestrial grounds. This correlates well with the findings of lead content in dust in areas surrounding a boatyard in Thailand where elevated levels in household dust was found several 100 m from the boatyard with decreasing distance to the boatyard (Maharachpong et al 2006).…”