Spatial and temporal trends of gas and particle phase atmospheric DDT and metabolites in Michigan: Evidence of long‐term persistence and atmospheric emission in a high‐DDT‐use fruit orchard

Abstract

[1] Michigan was among the top three apple producing states in the United States from the 1940s to 1969 when DDT was heavily used on its fruit orchards. More than 2 decades after Michigan banned DDT use in 1969, we collected air samples from four sites around the state to measure concentrations of six DDT-related compounds in the atmosphere. At South Haven, an apple producing area, average gas phase concentrations of DDT and DDE compounds were at least 10 times greater than the other sites including Pellston in the north, Deckerville in the east, and Dexter in south-central. Concentrations at South Haven showed a very strong seasonal cycle, an effect of higher air temperatures on moving these residues into the gas phase from a local source. We calculated DH values for all six compounds from the South Haven data which showed that p,p 0 -DDE was the highest at 108 kJ mol À1 . The DH values for all compounds at South Haven had a high correlation with Henry's Law Constant (HLC) (r = 0.7), verifying that HLC is a good indicator of tendency for compound conversion to the gas phase. South Haven was the only site with significant atmospheric particle-associated DDT. Particle/gas ratios there for p,p 0 -DDT and p,p 0 -DDE also had a predictable seasonal variation. Overall, these results show that agricultural sites with similar DDT use history will be continuous sources of atmospheric DDT for decades after application.

Atmospheric deposition and air‐sea gas exchange fluxes of DDT and HCH in the Yangtze River Estuary, East China Sea

“…The seasonal variation was particularly pronounced for DDT, with the highest concentrations in summer (40 ± 28 pg/m 3 ) and lower concentrations of 5 ± 3 pg/m 3 in autumn, 4 ± 3 pg/m 3 in spring, and 3 ± 2 pg/m 3 in winter, respectively (Figure ). These values indicate the possible short‐term input of DDT in summer because the concentration levels in summer were 1 order of magnitude higher than those in the other three seasons [ Hermanson et al , ]. A similar seasonal variation in DDT concentrations was reported by Ji et al [] in the same area; they also observed that concentrations in the gaseous phase were positively correlated with atmospheric temperature.…”

Remediation of DDT and Its Metabolites in Contaminated Sediment

“…Total concentrations of DDTR in air (gas + particle) were reported to be 170 to 240 pg/m 3 in the Pearl River Delta, China [112]. Hermanson et al [51] reported concentrations of the p,p'-isomers at four sites in Michigan were 1910 (DDT), 5420 (DDE), and 113 (DDD)pg/m 3 and for o,p'-DDT, DDE, and DDD were 687, 313, and 80 pg/m 3 . As previously described, DDTR are highly non-polar lipophilic compounds that have a low aqueous solubility ranging from 0.025 mg/L for p,p'-DDT to 0.14 mg/L for o,p'-DDE [5].…”

Derivation of flow rate and calibration method for high-volume air samplers

“…When the mass of particles is known, they can be processed further to determine the mass of each contaminant by using various analytical techniques, e.g., those used for various flame retardants by Salamova et al (2014). If contaminants in the gas phase are investigated, such as pesticides (Hermanson et al, 2007), additional analytical methods must be applied.…”

“…9.1. Most studies of atmospheric contaminants collected with Hi-Vol samplers assume that the calibration procedure is understood, rarely discuss calibration details, and never include the equations used, this includes Hermanson and Hites (1989), Monosmith and Hermanson (1996), Hermanson et al (1997Hermanson et al ( , 2003Hermanson et al ( , 2007, Basu et al (2009), Salamova et al (2014), and Hites (2018).…”