Nitrated monoaromatic hydrocarbons (nitrophenols, nitrocatechols, nitrosalicylic acids) in ambient air: levels, mass size distributions and inhalation bioaccessibility

Abstract

Nitrated monoaromatic hydrocarbons (NMAHs) are ubiquitous in the environment and an important part of atmospheric humic-like substances (HULIS) and brown carbon. They are ecotoxic and with underresearched toxic potential for humans. NMAHs were determined in size-segregated ambient particulate matter collected at two urban sites in central Europe, Ostrava and Kladno, Czech Republic. The average sums of 12 NMAHs (Σ12NMAH) measured in winter PM10 samples from Ostrava and Kladno were 102 and 93 ng m−3, respectively, and 8.8 ng m−3 in summer PM10 samples from Ostrava. The concentrations in winter corresponded to 6.3–7.3% and 2.6–3.1% of HULIS-C and water-soluble organic carbon (WSOC), respectively. Nitrocatechols represented 67–93%, 61–73% and 28–96% of NMAHs in PM10 samples collected in winter and summer at Ostrava and in winter at Kladno, respectively. The mass size distribution of the targeted substance classes peaked in the submicrometre size fractions (PM1), often in the PM0.5 size fraction especially in summer. The bioaccessible fraction of NMAHs was determined by leaching PM3 samples in two simulated lung fluids, Gamble’s solution and artificial lysosomal fluid (ALF). More than half of NMAH mass is found bioaccessible, almost complete for nitrosalicylic acids. The bioaccessible fraction was generally higher when using ALF (mimics the chemical environment created by macrophage activity, pH 4.5) than Gamble’s solution (pH 7.4). Bioaccessibility may be negligible for lipophilic substances (i.e. log KOW > 4.5).

Investigations into the gas-phase photolysis and OH radical kinetics of nitrocatechols: implications of intramolecular interactions on their atmospheric behaviour

“…Nitrocatechols have been found as tracer compounds in particulate matter emitted during biomass burning, correlating well with the levoglucosan and NO x levels (Kitanovski et al, 2012b, a;Salvador et al, 2021). In organic aerosols, the 4-nitrocatechol concentration exceeds in some cases 150 ng m −3 , whereas for methylated nitrocatechols the overall concentration can be as high as 821 ng m −3 (Iinuma et al, 2010;Kitanovski et al, 2021). These high concentrations of nitrated monoaromatic hydrocarbons were determined in the winter season and have been correlated with household wood-burning use.…”

“…These high concentrations of nitrated monoaromatic hydrocarbons were determined in the winter season and have been correlated with household wood-burning use. However, in these studies, all identified nitrocatechols may cover up to 96 % of the nitrated monoaromatic hydrocarbons found in PM 10 samples (Kitanovski et al, 2021). 4-nitrocatechol was found in the reaction of guaiacol initiated by OH radicals in the presence of NO x (Lauraguais et al, 2014).…”

Comment on acp-2021-553

“…Nitrocatechols have been found as tracer compounds in particulate matter emitted during biomass burning, correlating well with the levoglucosan and NOx levels (Kitanovski et al, 2012b(Kitanovski et al, , 2012aSalvador et al, 2021). In organic aerosols the 4-nitrocatechol concentration exceeds in some cases 150 ng × m -3 while for methylated nitrocatechols the overall concentration is as high as 821 ng × m -3 (Iinuma et al, 2010;Kitanovski et al, 2020). These high concentrations of nitrated monoaromatic hydrocarbons were determined in the winter season and have been correlated with household wood burning use.…”

“…These high concentrations of nitrated monoaromatic hydrocarbons were determined in the winter season and have been correlated with household wood burning use. However, in these studies, all identified nitrocatechols seem to cover up to 96% of the nitrated monoaromatic hydrocarbons found in PM10 samples (Kitanovski et al, 2020). 4-nitrocatechol was https://doi.org/10.5194/acp-2021-553 Preprint.…”

Comment on acp-2021-553

“…These high concentrations of nitrated monoaromatic hydrocarbons were determined in the winter season and have been correlated with household wood burning use. However, in these studies, all identified nitrocatechols seem to cover up to 96% of the nitrated monoaromatic hydrocarbons found in PM10 samples (Kitanovski et al, 2020). 4-nitrocatechol was found in the reaction of guaiacol initiated by the OH radicals in the presence of NOx (Lauraguais et al, 2014).…”