Abstract

Persistent Organic Pollutants (POPs) are globally distributed and are of great concern due to their persistence, carcinogenicity and endocrine-disrupting effects. POPs include a wide range of xenobiotic chemicals, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and brominated flame retardants (BFR). These chemicals have been detected in remote polar regions that lack historical usage and the atmosphere is considered to be the major pathway for their long-range transport. The collection of accurate atmospheric data for POPs is challenging for two reasons: firstly, there is a need to separate the prevailing background level of a POP from that arising from local sources; and secondly, accurately estimating low background levels with respect to contamination of samples and analytical sensitivity. The first difficulty can, in principle be resolved by sampling far from local sources, e.g. in the open ocean or Antarctica. The constraint is that remote sampling is more expensive and challenging to conduct. Reports on global background levels of POPs in the literature are therefore sparse - even though such data are of primary interest to gain a better understanding of their global fate and transport. This chapter reports several new developments in the collection and analysis of atmospheric POPs, including a cost-effective solution to air sampling over the open ocean. Sampling data are reported from the Indian Ocean - as acquired by Jocara Indian Ocean Quest, an expeditionary voyage that used a self-fabricated air sampler to collect atmospheric samples onboard a sailing vessel. The ability to sample without running an engine greatly reduces sample contamination. Atmospheric samples were collected over polyurethane foam (PUF) plugs. An efficient microwave-assisted extraction (MAE) technique is described that can be used both for pre-cleaning PUF plugs and sample extraction. Details are also provided on quality control procedures - crucial for establishing statistically-significant estimates of background POP levels. This methodology outlined in this chapter represents a novel, cost-effective and accurate technique for measuring atmospheric POP concentrations.