Atmospheric seasonal trends and environmental rate of alkylphenols in the lower Hudson River Estuary

The atmospheric occurrence of nonylphenols and tert-octylphenol has been as sessed at three sites in the lower Hudson River Estuary (LHRE). The samples (n = 186) were taken from June to December of 1998. Gas-phase nonylphenol (NP) concentrations at a coastal site (Sandy Hook) ranged from below the de tection limit (DL) to 56.3 ng m(-3), while concentrations at a suburban sit e (New Brunswick) ranged from 0.13 to 81 ng m(-3). Gas-phase concentrations of tert-octylphenol (tOP) ranged from <DL to 1.0 ng m(-3) at Sandy Hook an d from 0.01 to 2.5 ng m(-3) at New Brunswick. NPs and tOP exhibited seasona l dependence with higher gas-phase concentrations during summer than during fall and early winter. Temperature explained 40-62% of the variability in the log (gas phase) NP and tOP concentrations. Assessment of the influence of local wind direction on atmospheric NP concentrations provided evidence for the predominance of local sources rather than long-range transport. Bas ed on simultaneous wafer and over-water gas-phase samples and subsequent es timation of air-water exchange fluxes, volatilization and advection to the Atlantic Ocean accounted for 40 and 26% of the removal of NPs from the wate r column of the LH RE, respectively. The estimated ha If-life of NPs in the water column of the LHRE was 9 days.