Polychlorinated Naphthalenes in the Global Atmospheric Passive Sampling (GAPS) Study

Air concentrations of polychlorinated naphthalenes
(PCNs) were measured as part of the Global Atmospheric
Passive Sampling (GAPS) study to assess their spatial
distribution on a worldwide basis for the first sampling period
between December 2004 and March 2005. Results from
more than 40 sites on seven continents show that PCNs are
widespread, and highest levels are detected in urban/industrial locations consistent with other air sampling studies.
The geometric mean air concentration of ΣPCN is 1.6 pg/m3, ranging from below detection limit to 32 pg/m3.
With technical PCN mixtures largely no longer produced,
combustion inputs may be contributing increasingly to
contemporary PCN air burden globally. Enrichment
of combustion-related congeners, e.g., PCN-52/60, -50,
-51, -54, and -66/67, is observed in the congeneric compositions
of air at nearly all sites compared to relatively minor
contribution of these congeners in technical PCN formulations.
Further evidence of current combustion sources influencing
global PCN levels is a higher relative abundance of
combustion-related congeners quantified by ΣPCNcombustion/ΣPCN. The relative contribution by combustion sources
and emissions from technical PCN mixtures is expected to
vary among sites since it depends on the combustion
sources and the technical mixture used in a particular
country or region.