Maldives: an archipelago that burns. A first survey of PCDD/Fs and DL-PCBs from human activities

Due to its geographical peculiarities, the Republic of Maldives represents a case study of great interest for the investigation of persistent organic pollutants, from both a socio-economic and an ecological perspective. Thus, we conducted a first survey to assess the current status of polychlorinated dibenzo-p-dioxin (PCDD), polychlorinated dibenzofuran (PCDF) and dioxin-like polychlorinated biphenyl (DL-PCB) concentrations in Maldivian soils. The range for PCDD/F and DL-PCB soil concentrations was 0.01-49.3 pg WHO2005-TEQ g(-1) and 0.01-3.69 pg WHO2005-TEQ g(-1) dw respectively. PCDD/F concentrations exceeding several international soil guidelines were found in samples from locations in the proximity of local waste combustion sources. DL-PCB concentrations were lower than PCDD/Fs and comparable to those in previous reports from background areas and in areas with developing industrial and agricultural activities. PCDD/F and DL-PCB levels (expressed as WHO2005-TEQ) in soils were strongly correlated (r=0.89), which suggests that, in most of the sites, they are originated from the same emission sources. Results indicate that PCDD/F soil concentrations (expressed as WHO2005-TEQ) tend to decrease with the distance from the local pollution sources. Principal component analysis (PCA) showed that PCDD/Fs in the most polluted locations are mainly generated by waste combustion. These findings highlight the need for immediate changes in waste management policies in the Archipelago, in order to reduce the release of Persistent Organic Pollutants (POPs) in the fragile local environment.