Saturation diving; physiology and pathophysiology.

In saturation diving, divers stay under pressure until most of their tissues are saturated with breathing gas. Divers spend a long time in isolation exposed to increased partial pressure of oxygen, potentially toxic gases, bacteria, and bubble formation during decompression combined with shift work and long periods of relative inactivity. Hyperoxia may lead to the production of reactive oxygen species (ROS) that interact with cell structures, causing damage to proteins, lipids, and nucleic acid.

Cognitive symptoms and welding fume exposure.

Background: Prevalence of moderate to severe cognitive symptoms is markedly higher in UK professional divers who have also worked as a welder (28%) than in either divers who have not welded (18%) or offshore workers who have worked neither as a diver nor as a welder (6%).

Objectives: To determine whether cognitive symptoms are related to welding fume exposure or diving.

Methods: Three age-matched groups of male workers were studied using postal questionnaire: professional divers who had worked as a welder (PDW, n = 361), professional welders who had not dived (NDW, n = 352), and offshore oil field workers who had neither dived nor welded (NDNW, n =503).

Lack of effect of nitrogen dioxide exposure on heart rate variability in patients with stable coronary heart disease and impaired left ventricular systolic function.

Objectives: Epidemiological studies of air pollution on cardiovascular health show associations of cardiac mortality and admissions with exposure to nitrogen dioxide (NO(2)) at low concentrations. These associations could be causal or NO(2) could be acting as a surrogate measure for another air pollutant, most likely ultrafine particles. No studies of cardiac susceptibility to acute exposure to NO(2) have been undertaken.

Hearing symptoms and audiometry in professional divers and offshore workers.

Aims: The aims are to compare hearing loss between professional divers and offshore workers and to study whether hearing loss symptoms reflected physical disorder. A secondary objective was to study total threshold shift assessment as a method of detecting noise-induced hearing loss (NIHL).

Methods: Participants (151 divers and 120 offshore workers) completed a questionnaire for symptoms and screening audiometry.

Health status of professional divers and offshore oil industry workers.

Aims: To compare the health status of UK professional divers and age-matched non-divers and to contrast offshore divers (OSDs) with non-offshore divers (NOSDs).

Methods: A postal survey sent to 2958 male professional divers, registered with the UK Health & Safety Executive (HSE) before 1991, and 2708 men who had worked in the offshore oil industry in 1990-92 (non-divers). The questionnaire addressed lifestyle, occupation and health status.

Objective neuropsychological test performance of professional divers reporting a subjective complaint of "forgetfulness or loss of concentration".

Objective: This study attempted to determine whether the higher prevalence of reported "forgetfulness or loss of concentration" among professional divers can be confirmed using objective neuropsychological tests. Secondary aims were to qualify the functional nature of the complaints and to ascertain whether reduced performance was linked to diving history.

Methods: In a case-control study, the neuropsychological test performance of divers complaining of moderate or severe "forgetfulness or loss of concentration" was compared with two age-matched control groups reporting no or slight "forgetfulness or loss of concentration" ("nonforgetful" divers and "nonforgetful" nondivers).

Effect of hypobaric hypoxia, simulating conditions during long-haul air travel, on coagulation, fibrinolysis, platelet function, and endothelial activation.

Context: The link between long-haul air travel and venous thromboembolism is the subject of continuing debate. It remains unclear whether the reduced cabin pressure and oxygen tension in the airplane cabin create an increased risk compared with seated immobility at ground level.

Objective: To determine whether hypobaric hypoxia, which may be encountered during air travel, activates hemostasis.