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Previous efforts to measure atmospheric iodine have focused on marine and coastal regions. We report the first ground‐based tropospheric iodine monoxide (IO) radical observations over the central continental United States. Throughout April 2022, IO columns above Storm Peak Laboratory, Colorado (3,220 m.a.s.l.) ranged from 0.7 ± 0.5 to 3.6 ± 0.5 × 1012(average: 1.9 × 1012molec cm−2). IO was consistently elevated in air masses transported from over the Pacific Ocean. The observed IO columns were up to three times higher and the range was larger than predicted by a global model, which warrants further investigation into iodine sources, sinks, ozone loss, and particle formation. IO mixing ratios increased with altitude. At the observed levels, iodine may be competitive with bromine as an oxidant of elemental mercury at cold temperatures typical of the free troposphere. Iodine‐induced mercury oxidation is missing in atmospheric models, understudied, and helps explain model underestimation of oxidized mercury measurements. Halogens such as chlorine, bromine, and iodine are highly reactive gases that participate in atmospheric chemistry, including ozone destruction, particle formation, modification of greenhouse gas lifetime (i.e., methane, dimethylsulfide), and the oxidation of elemental mercury. Iodine mainly enters the atmosphere from oceans; therefore, past measurements of atmospheric iodine have focused on marine and polar regions. This study describes the first lower atmospheric measurements of iodine monoxide (IO) radicals at a remote mountaintop site in the central continental United States. These measurements indicate that the concentration of IO radicals showed a large range over the course of 1 month and reached levels up to three times higher than predicted by a global atmospheric chemistry model. These observations suggest that our understanding of the iodine sources and sinks to the free troposphere may be incomplete. Moreover, we suggest that iodine's contribution to ozone destruction and mercury chemistry may be underestimated; in particular, iodine may be competitive with bromine in the oxidation of elemental mercury in the free troposphere. Measurements of iodine monoxide radicals at Storm Peak Laboratory are up to three times higher than predicted by GEOS‐ChemIO tropospheric column variability is significant and highlights a need to better understand sources and sinks of tropospheric iodineIodine may rival bromine as a tropospheric mercury oxidant; iodine‐mercury chemistry is understudied and missing in atmospheric models Measurements of iodine monoxide radicals at Storm Peak Laboratory are up to three times higher than predicted by GEOS‐Chem IO tropospheric column variability is significant and highlights a need to better understand sources and sinks of tropospheric iodine Iodine may rival bromine as a tropospheric mercury oxidant; iodine‐mercury chemistry is understudied and missing in atmospheric models

Objective:To estimate the frequency of delay in referral for palliative radiotherapy (PRT), and to identify factors associated with delay. Design:Prospective survey over three months in 1997. Setting:Radiotherapy department of a cancer centre in Melbourne, Victoria. Participants:158 consecutive patients prescribed PRT in the lung, breast, urology and haematology units. Main outcome measures:Duration of symptoms; incidence of "unreasonable" delay in referral; and incidence of negative clinical outcome associated with referral delay. Results:The median duration of symptoms before prescription of radiotherapy was four weeks. Thirty‐eight patients (24%) were considered to have had an unreasonable delay in referral, with median symptom duration of 15 weeks, and median delay in referral of 12 weeks. Causes of delay were classified as "diagnostic uncertainty" (29%), "other treatment given" (18%), "patient related" (18%), "language difficulty” (3%), and "unexplained" (32%). Twenty‐seven of these 38 patients (71%) had negative outcomes, including persistent pain, neurological deterioration and persistent respiratory symptoms. Conclusions:These data suggest that delay in referral for PAT is not uncommon, has a variety of causes and can result in negative clinical outcomes. There appears to be a need for greater awareness of patients' symptoms and of the role of PRT among clinicians caring for patients with cancer.