Epidemiological studies based on Danish registries have observed that Danish male firefighters have more cardiovascular disease, infertility diagnose and a trend to increased risk of cancer than other Danish employed males. Firefighting activities include a combination of stressors such as strenuous work under heat, smoke and soot known to be able to affect cardiovascular and reproductive health, with smoke and soot also being known to increase the risk of cancer. The training facilities of real-fire extinguishing exercises in Denmark operate using wood or natural gas fire, which will have differential gradients of smoke, soot and possibly heat. The investigators will use different training conditions to create gradients of the different stressors and investigate health effects thereof. With this approach, the investigators expect to be able to evaluate the individual contribution of the different stressors in markers of cardiovascular, cancer and reproductive health risk. The project will include approx. 35 young conscript participants on a firefighting course, followed in four sessions, three firefighting training sessions under different fire conditions (no fire, wood fire and gas fire) and one control scenario.
Age range
18 Years
Sex
ALL
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Change in reactive hyperemia index - afternoon
Timeframe: Baseline afternoon measurement, afternoon measurement immediately after firefighting without fire, afternoon measurement immediately after firefighting under wood fire and afternoon measurements immediately after firefighting under gas fire
Change in reactive hyperemia index - morning
Timeframe: Baseline morning measurement, morning measurement in subsequent day after firefighting without fire, morning measurement in subsequent day after firefighting under wood fire and morning measurement in subsequent day after firefighting under gas fire
Change in Heart Rate Variability pNN50 at rest - afternoon
Timeframe: Baseline afternoon measurement, afternoon measurement immediately after firefighting without fire, afternoon measurement immediately after firefighting under wood fire and afternoon measurements immediately after firefighting under gas fire
Change in Heart Rate Variability pNN50 at rest - morning
Timeframe: Baseline morning measurement, morning measurement in subsequent day after firefighting without fire, morning measurement in subsequent day after firefighting under wood fire and morning measurement in subsequent day after firefighting under gas fire
Change in Heart Rate Variability RMSSD at rest - afternoon
Timeframe: Baseline afternoon measurement, afternoon measurement immediately after firefighting without fire, afternoon measurement immediately after firefighting under wood fire and afternoon measurements immediately after firefighting under gas fire
Change in Heart Rate Variability RMSSD at rest - morning
Timeframe: Baseline morning measurement, morning measurement in subsequent day after firefighting without fire, morning measurement in subsequent day after firefighting under wood fire and morning measurement in subsequent day after firefighting under gas fire
Change in Heart Rate Variability ratio LF/HF at rest - afternoon
Timeframe: Baseline afternoon measurement, afternoon measurement immediately after firefighting without fire, afternoon measurement immediately after firefighting under wood fire and afternoon measurements immediately after firefighting under gas fire
Change in Heart Rate Variability ratio LF/HF at rest - morning
Timeframe: Baseline morning measurement, morning measurement in subsequent day after firefighting without fire, morning measurement in subsequent day after firefighting under wood fire and morning measurement in subsequent day after firefighting under gas fire
Changes in levels of 8-oxodG excretion in first morning urine
Timeframe: Baseline, before firefighting without fire, day after firefighting without fire, before firefighting under wood fire, day after firefighting under wood fire, before firefighting under gas fire, day after firefighting under gas fire
Changes in levels of DNA strand breaks in peripheral blood mononuclear cells
Timeframe: Baseline, before firefighting without fire, day after firefighting without fire, before firefighting under wood fire, day after firefighting under wood fire, before firefighting under gas fire, day after firefighting under gas fire
Changes in core temperature
Timeframe: Baseline day, during the day of firefighting without fire, during the day of firefighting under wood fire and during the day of firefighting under gas fire.
Changes in scrotal temperature
Timeframe: Baseline day, during the day of firefighting without fire, during the day of firefighting under wood fire and during the day of firefighting under gas fire.
Changes in scrotal thermoregulation
Timeframe: Baseline day, during the day of firefighting without fire, during the day of firefighting under wood fire and during the day of firefighting under gas fire.
Changes in levels of circulating micro RNA
Timeframe: Baseline, before firefighting without fire, day after firefighting without fire, before firefighting under wood fire, day after firefighting under wood fire, before firefighting under gas fire, day after firefighting under gas fire
Changes in urinary potency of AhR activation
Timeframe: Baseline, before firefighting without fire, day after firefighting without fire, before firefighting under wood fire, day after firefighting under wood fire, before firefighting under gas fire, day after firefighting under gas fire
Changes in potency of AhR activation from skin deposits
Timeframe: Baseline, before firefighting without fire, immediately after firefighting without fire, before firefighting under wood fire, immediately after firefighting under wood fire, before firefighting under gas fire, immediately after firefighting under gas