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Safety and Hygiene
Published in Jiri George Drobny, Radiation Technology for Polymers, 2020
The biological effects of UV radiation result mostly from exposure to wavelengths below 325 nm and resemble the typical syndromes of sunburn, such as skin reddening (erythema), skin burning, dryness, premature aging, and pigmentation. Eyes may be also affected by developing inflammation, pain, photophobia, tearing, temporary blindness, and cataracts.1 The eyes are most sensitive to UV radiation from 210 nm (UVC and UVB). Maximum absorption by the cornea occurs around 280 nm. Absorption of UVA in the lens may be a factor in producing cataracts (clouding of the lens in the eye). Acute overexposure of the eye to UV radiation can cause photokeratitis (inflammation of the cornea) and photoconjunctivitis (inflammation of the cornea, more commonly known as “snow blindness” or “welders’ flash”). Symptoms range from mild irritation to severe pain and, in an extreme case, to irreversible damage.2
Headache
Published in Anthony N. Nicholson, The Neurosciences and the Practice of Aviation Medicine, 2017
With the onset of headache, patients usually develop nausea and may vomit – most commonly occurring about an hour after the headache has begun. Other symptoms of heightened ‘sensitivity’ include photophobia and phonophobia. Patients may also report the dislike of strong odours (osmophobia), but this symptom needs to be distinguished from strong smells that can be a trigger for some auras (see below) and from the occasional patient who has temporal lobe epilepsy associated with olfactory hallucinations followed by a headache. The patient with migraine generally prefers to lie down in a darkened room until the headache has settled (usually getting into bed rather than lying on top of it), and they will often become irritable if unnecessarily stimulated. However, some patients with migraine may be able to continue to function (for example, if at work), albeit at a reduced level. Patients usually look pale and will report that movement aggravates their symptoms. The headache of migraine usually settles after sleep, but may last up to two to three days. After the headache has disappeared, many patients will still feel lethargic and ‘not with it’ for several further days.
INTRODUCTION AND OVERVIEW OF PART 2
Published in Nicholas P. Cheremisinoff, Industrial Solvents Handbook, Revised And Expanded, 2003
Chemical Designations — Synonyms; 2-Propen-l-o!-Vinytcarbinol; Chemical Formula: CHI=CHCH2OH. Observable Characteristics — Physical State (as normally shipped): Liquid; Color: Colorless; Odor: Characteristic, pungent; sharp; causes tears. Physical and Chemical Properties — Physical State at 15 °C and 1 atm.: Liquid; Molecular Weight: 58.08; Boiling Point at 1 atm.: 206, 96.9, 370.1; Freezing Point: -200, -129, 144; Critical Temperature: 521.4, 271.9, 545.1; Critical Pressure: 840, 57, 5.8; Specific Gravity: 0.852 at 20°C (liquid); Vapor (Gas) Density: 2.0; Ratio of Specific Heats of Vapor (Gas): 1.12; Latent Heat of Vaporization: 295, 164, 6.87; Heat of Combustion: -13,720, -7620, -319.0; Heat of Decomposition: Not pertinent. Health Hazards Information — Recommended Personal Protective Equipment: Organic canister or air pack; rubber gloves, goggles; other protective equipment as required to prevent all body contact; Symptoms Following Exposure: Vapors are quite irritating to eyes, nose and throat. Eye irritation may be accompanied by complaints of photophobia and pain in the eyeball; pain may not begin until 6 hours after exposure. Liquid may cause firstand second-degree burns of the skin, with blister formation; underlying part will become swollen and painful, and local muscle spasms may occur; General Treatment for Exposure: INHALATION: remove victim from contaminated area and administer oxygen; get medical attention immediately. SKIN: remove liquid with soap and water. EYES: Hush with continuous stream of water for 15 min.; Toxicity by Inhalation (Threshold Limit Value): 2 ppm; Short-Term Exposure Limits: 5 ppm for 30 min; Toxicity by Ingestion: Grade 3; LDj0= 50 to 500 mg/kg (mouse, rat); Late Toxicity: Data not available; Vapor (Gas) Irritant Characteristics: Vapor is moderately irritating such that personnel will not usually tolerate moderate or high vapor concentration; Liquid or Solid Irritant Characteristics: Causes smarting of the skin and first-degree burns on short exposure; may cause secondary burns on a long exposure; Odor Threshold: 0.78 ppm. Fire Hazards — Flash Point ("F): 72 CC; 90 OC; Flammable Limits in Air (%): 2.5 - 18; Fire Extinguishing Agents: Dry chemical, alcohol foam, carbon dioxide; Fire Extinguishing Agents Not To Be Used: Water may be ineffective; Special Hazards of Combustion Products: Toxic vapor is generated when heated; Behavior in Fire: Vapor heavier than air and may travel a considerable distance to a source of ignition and flash back; Ignition Temperature (°F); 829; Electrical Hazard: Not pertinent; Burning Rate: 2.7 mm/min. Chemical Reactivity — Reactivity with Water: No reaction; Reactivity with Common Materials: No reaction; Stability During Transport: Stable at ordinary temperatures and pressures; Neutralizing Agents for Acids and Caustics: Not pertinent; Polymerization: Not pertinent; Inhibitor of Polymerization; Not pertinent.
Photoreceptor Enhanced Light Therapy (PELT): A Framework for Implementing BiologicallyDirected Integrative Lighting
Published in LEUKOS, 2023
Beatrix Feigl, Drew D. Carter, Andrew J. Zele
In personalizing the desired PELT protocol to re-align circadian rhythms to the 24-h day–night cycle, the rod, cone and melanopsin photoreceptor function can be quantified in practice using pupillometry (Adhikari et al. 2016a; Kelbsch et al. 2019). Alternatively, the literature can inform the typical manifest photoreceptor loss for the patient at their disease stage, or for the seasonal, work or travel-dependent desynchrony. The PrD stimuli are chosen depending on the user requirements in healthy people or those with disease and can be implemented as a room illuminant or portable device for bright light therapy (Fig. 1). Initially, it may be most practical to apply the maximum PrD contrast generated by a device to better utilize the available hardware to provide a physiological benefit. PELT can also be applied in laboratory studies to evaluate the effects of light mediated via all five photoreceptors on human physiology and performance, including the inadvertent negative impacts of artificial lighting such as headaches, fatigue, eye strain (Auffret et al. 2021; Joines et al. 2015) and photophobia (Zele et al. 2021). Such clinical and laboratory studies will be critical for providing the evidence-base for future light therapy protocols.
Analysis of bicycle helmet damage visibility for concussion-threshold impacts
Published in International Biomechanics, 2021
Ana Cachau-Hansgardh, Caitlin McCleery, Manon Limousis-Gayda, Rami Hashish
Universal agreement on what constitutes a concussion, a form of mTBI, has long challenged the scientific community. Many definitions build on reported symptoms such as the one proposed by the American Orthopaedic Society for Sports Medicine Concussion Workshop Group: ‘Any alteration in cerebral function caused by a direct or indirect (rotation) force transmitted to the head resulting in one or more of the following acute signs or symptoms: a brief loss of consciousness, light-headedness, vertigo, cognitive and memory dysfunction, tinnitus, blurred vision, difficulty concentrating, amnesia, headache, nausea, vomiting, photophobia, or a balance disturbance’. (Wojtys et al. 1999). However, a purely quantitative definition is required for helmet design and experimentation purposes, such as an injury threshold based upon peak linear acceleration.
Performance of a new device for the clinical determination of light discomfort
Published in Expert Review of Medical Devices, 2020
Robert Montés-Micó, Alejandro Cerviño, Noelia Martínez-Albert, José V. García-Marqués, Sarah Marie
Research on discomfort glare has been conducted mainly in two major areas: architecture and pathology/medicine. First studies on lighting started a century ago with the arrival of new lighting sources [2–4]. Research in this field is still very active nowadays on glare indexes that compute light environments in order to evaluate comfort acceptance [5–9]. These indexes are useful for creating comfortable lighting environments for a population but do not ensure self-perceived comfort of an individual [10]. Studies on physiological parameters that can affect discomfort [10] or as an indicator of discomfort [11] in medicine explored photophobia, that is an extreme condition of discomfort glare. With photophobia, normal light levels produce or increase pain [12,13], and is often associated with neurological disorders like migraine or brain injury [14,15], ophthalmic disease [16] (dry eyes or retina pathology), or as a secondary effect of drugs [15].