Unusual early peaks of airborne ragweed (Ambrosia L.) pollen in the Pannonian Biogeographical Region.

Early peaks of airborne ragweed (Ambrosia L.) pollen concentrations were observed at several monitoring stations in Hungary in June 2017 and 2018, one month before the usual start of the pollen season at the end of July. Backward trajectories were calculated to simulate potential sources of pollen collected at different locations in the Pannonian Biogeographical Region. In a collaboration between aerobiological and phenological networks, a nationwide campaign was conducted to collect field data of ragweed blooming. During field surveys, ragweed plants having extremely early blooming were found most abundantly in a rural site near Vaja (North-East Hungary) and other locations in Hungary. Field observations matched with source areas identified by trajectory analyses; i.e., early-flowering ragweed plants were found at some of these locations. Although similar peaks of airborne pollen concentrations were not detected in other years (e.g., 2016, 2019-2021), alarming results suggest the possibility of expanding seasons of ragweed allergy.

Ozone-initiated terpene reaction products in five European offices: replacement of a floor cleaning agent.

Cleaning agents often emit terpenes that react rapidly with ozone. These ozone-initiated reactions, which occur in the gas-phase and on surfaces, produce a host of gaseous and particulate oxygenated compounds with possible adverse health effects in the eyes and airways. Within the European Union (EU) project OFFICAIR, common ozone-initiated reaction products were measured before and after the replacement of the regular floor cleaning agent with a preselected low emitting floor cleaning agent in four offices located in four EU countries. One reference office in a fifth country did not use any floor cleaning agent. Limonene, α-pinene, 3-carene, dihydromyrcenol, geraniol, linalool, and α-terpineol were targeted for measurement together with the common terpene oxidation products formaldehyde, 4-acetyl-1-methylcyclohexene (4-AMCH), 3-isopropenyl-6-oxo-heptanal (IPOH), 6-methyl-5-heptene-2-one, (6-MHO), 4-oxopentanal (4-OPA), and dihydrocarvone (DHC). Two-hour air samples on Tenax TA and DNPH cartridges were taken in the morning, noon, and in the afternoon and analyzed by thermal desorption combined with gas chromatography/mass spectrometry and HPLC/UV analysis, respectively. Ozone was measured in all sites. All the regular cleaning agents emitted terpenes, mainly limonene and linalool. After the replacement of the cleaning agent, substantially lower concentrations of limonene and formaldehyde were observed. Some of the oxidation product concentrations, in particular that of 4-OPA, were also reduced in line with limonene. Maximum 2 h averaged concentrations of formaldehyde, 4-AMCH, 6-MHO, and IPOH would not give rise to acute eye irritation-related symptoms in office workers; similarly, 6-AMCH, DHC and 4-OPA would not result in airflow limitation to the airways.