Air Conditioning
Heat Exhaustion
Ventilation
Air Microbiology
Heating
Automobiles
Conditioning, Classical
Air
Environmental Exposure
Transplantation Conditioning
A community outbreak of Legionnaires' disease linked to hospital cooling towers: an epidemiological method to calculate dose of exposure. (1/184)
BACKGROUND: From July to September 1994, 29 cases of community-acquired Legionnaires' disease (LD) were reported in Delaware. The authors conducted an investigation to a) identify the source of the outbreak and risk factors for developing Legionella pneumophila serogroup 1 (Lp-1) pneumonia and b) evaluate the risk associated with the components of cumulative exposure to the source (i.e. distance from the source, frequency of exposure, and duration of exposure). METHODS: A case-control study matched 21 patients to three controls per case by known risk factors for acquiring LD. Controls were selected from patients who attended the same clinic as the respective case-patients. Water samples taken at the hospital, from eight nearby cooling towers, and from four of the patient's homes were cultured for Legionella. Isolates were subtyped using monoclonal antibody (Mab) analysis and arbitrarily primed polymerase chain reaction (AP-PCR). RESULTS: Eleven (52%) of 21 case-patients worked at or visited the hospital compared with 17 (27%) of 63 controls (OR 5.0, 95% CI : 1.1-29). For those who lived, worked, or visited within 4 square miles of the hospital, the risk of illness decreased by 20% for each 0.10 mile from the hospital; it increased by 80% for each visit to the hospital; and it increased by 8% for each hour spent within 0.125 miles of the hospital. Lp-1 was isolated from three patients and both hospital cooling towers. Based on laboratory results no other samples contained Lp-1. The clinical and main-tower isolates all demonstrated Mab pattern 1,2,5,6. AP-PCR matched the main-tower samples with those from two case-patients. CONCLUSION: The results of our investigation suggested that the hospital cooling towers were the source of a community outbreak of LD. Increasing proximity to and frequency of exposure to the towers increased the risk of LD. New guidelines for cooling tower maintenance are needed. Knowing the location of cooling towers could facilitate maintenance inspections and outbreak investigations. (+info)Buildings operations and ETS exposure. (2/184)
Mechanical systems are used in buildings to provide conditioned air, dissipate thermal loads, dilute contaminants, and maintain pressure differences. The characteristics of these systems and their operations h implications for the exposures of workers to environmental tobacco smoke (ETS) and for the control of these exposures. This review describes the general features of building ventilation systems and the efficacy of ventilation for controlling contaminant concentrations. Ventilation can reduce the concentration of ETS through dilution, but central heating, ventilating, and air conditioning (HVAC) can also move air throughout a building that has been contaminated by ETS. An understanding of HVAC systems is needed to develop models for exposures of workers to ETS. (+info)Germicidal ultraviolet irradiation in air conditioning systems: effect on office worker health and wellbeing: a pilot study. (3/184)
OBJECTIVES: The indoor environment of modern office buildings represents a new ecosystem that has been created totally by humans. Bacteria and fungi may contaminate this indoor environment, including the ventilation systems themselves, which in turn may result in adverse health effects. The objectives of this study were to test whether installation and operation of germicidal ultraviolet (GUV) lights in central ventilation systems would be feasible, without adverse effects, undetected by building occupants, and effective in eliminating microbial contamination. METHODS: GUV lights were installed in the ventilation systems serving three floors of an office building, and were turned on and off during a total of four alternating 3 week blocks. Workers reported their environmental satisfaction, symptoms, as well as sickness absence, without knowledge of whether GUV lights were on or off. The indoor environment was measured in detail including airborne and surface bacteria and fungi. RESULTS: Airborne bacteria and fungi were not significantly different whether GUV lights were on or off, but were virtually eliminated from the surfaces of the ventilation system after 3 weeks of operation of GUV light. Of the other environmental variables measured, only total airborne particulates were significantly different under the two experimental conditions--higher with GUV lights on than off. Of 113 eligible workers, 104 (87%) participated; their environmental satisfaction ratings were not different whether GUV lights were on or off. Headache, difficulty concentrating, and eye irritation occurred less often with GUV lights on whereas skin rash or irritation was more common. Overall, the average number of work related symptoms reported was 1.1 with GUV lights off compared with 0.9 with GUV lights on. CONCLUSION: Installation and operation of GUV lights in central heating, ventilation and air conditioning systems of office buildings is feasible, cannot be detected by workers, and does not seem to result in any adverse effects. (+info)Follow up investigation of workers in synthetic fibre plants with humidifier disease and work related asthma. (4/184)
OBJECTIVE: To investigate the clinical and sociomedical outcome in patients with various clinical manifestations of humidifier disease and work related asthma after removal from further exposure. METHODS: Follow up investigation (range 1-13 years) of respiratory symptoms, spirometry, airway responsiveness, sickness absence, and working situation in patients with (I) humidifier fever (n = 12), (II) obstructive type of humidifier lung (n = 8), (III) restrictive type of humidifier lung (n = 4), and (IV) work related asthma (n = 22). All patients were working at departments in synthetic fibre plants with microbiological exposure from contaminated humidification systems or exposure to small particles (< 1 micron) of oil mist. RESULTS: At follow up patients with work related asthma were less often symptom free (37%, 7/19) than patients with humidifier disease (I, II, III) (67%, 16/24). Mean forced expiratory volume in one second (FEV1) of patients with obstructive impairment had been increased significantly at follow up but still remained below the predicted value. Mean forced vital capacity (FVC) of patients with initially restrictive impairment had returned to normal values at follow up. Airway hyperresponsiveness at diagnosis persisted in patients with obstructive impairment (II + IV 14/17, but disappeared in patients with humidifier fever (3/3) and restrictive type of humidifier lung (2/2). In patients with obstructive impairment (II + IV), FVC and FEV1 at diagnosis were negatively associated with the duration between onset of symptoms and diagnosis and the number of years of exposure. Those with positive pre-employment history of respiratory disease had a lower FEV1 at diagnosis. Sickness absence due to respiratory symptoms decreased in all groups of patients after removal from further exposure, but this was most impressive in patients with the humidifier lung (II, III) and patients with work related asthma (IV). At follow up 83% of the patients were still at work at the same production site, whereas 11% received a disability pension because of respiratory disease. CONCLUSION: In patients with work related respiratory disease caused by exposure from contaminated humidification systems or oil mist, removal from further exposure resulted in clinical improvement, although, especially in those with obstructive impairment, signs persisted. Because of the possibility of transferring patients to exposure-free departments most patients could be kept at work. (+info)Airborne infection in a fully air-conditioned hospital. I. Air transfer between rooms. (5/184)
Measurements have been made of the extent of air exchange between patient rooms in a fully air-conditioned hospital using a tracer-gas method. When the rooms were ventilated at about six air changes per hour, had an excess airflow through the doorway of about 0.1 m.3/sec. and the temperature difference between rooms and corridor was less than 0.5 degrees C., concentrations of the tracer in rooms close to that in which it was being liberated were 1000-fold less than that in the source room. This ratio fell to about 200-fold in the absence of any excess airflow through the doorways. Considerable dilution took place along the corridors so that the concentration fell by around 10-fold for every 10 m. of corridor. (+info)Airborne infection in a fully air-conditioned hospital. II. Transfer of airborne particles between rooms resulting from the movement of air from one room to another. (6/184)
Experiments were conducted simultaneously with gas and particle tracers to determine the relative loss of particles between source and recipient sites in the hospital ward units. The magnitude of this loss could be accounted for by the assumption of sedimentation from well-mixed air masses during the time required for movement between source and recipients sites. As a consequence of this loss the degree of isolation between patient rooms for airborne particles was between 4 and 25 times greater than that for gaseous contamination, which reflects the actual transport of air between the rooms. The design and construction of portable spinning-disk particle generators suitable for field studies is discussed. (+info)Airborne infection in a fully air-conditioned hospital. II. Transport of gaseous and airborne particulate material along ventilated passageways. (7/184)
A mathematical model is described for the transport of gaseous or airborne particulate material between rooms along ventilated passageways. Experimental observations in three hospitals lead to a value of about 0.06 m.2/sec. for the effective diffusion constant in air without any systematic directional flow. The 'constant' appears to increase if there is any directional flow along the passage, reaching about 0.12 m. 2/sec. at a flow velocity of 0.04 m./sec. Together with previously published methods the present formulae make it possible to calculate the expected average amounts of gaseous or particulate material that will be transported from room to room in ventilated buildings in which the ventilation and exchange airflows can be calculated. The actual amounts transported in occupied buildings, however, vary greatly from time to time. (+info)Airborne infection in a fully air-conditioned hospital. IV. Airborne dispersal of Staphylococcus aureus and its nasal acquisition by patients. (8/184)
Studies in a newly built hospital furnished with complete air conditioning where most of the patients are nursed in 6-bed rooms showed that the transfer of air from one patient room to another was very small, especially when there was substantial flow of air in a consistent direction between the patient rooms and the corridor, and that the direct transfer of airborne particles was even less. There was, however, no evidence of any reduction in the rates of nasal acquisition of Staphylococcus aureus compared with those to be found in naturally ventilated hospitals. The numbers of Staph. aureus found in the air of a given room that appeared to have originated from patient carriers in other rooms were many times greater than could be accounted for by direct airborne transfer. Although there was evidence that many carriers were not detected, detailed study showed that this excess transfer to the air of other rooms was genuine. It seems probable on the basis of investigations in this hospital and elsewhere that this excess transfer occurs indirectly, through dispersal from the clothing of the nursing and medical staff into the air of another room of strains with which their outer clothes have become contaminated while dealing with patients. Reduction in direct airborne transfer of micro-organisms from one room to another, whether by ventilation or other means, can only be of clinical advantage if transfer by other routes is, or can be made, less than that by the direct airborne route. (+info)Air conditioning is the process of controlling and maintaining a comfortable indoor environment through the regulation of temperature, humidity, air movement, and cleanliness. It typically involves the use of mechanical systems that circulate and treat air to meet specific comfort requirements. The goal of air conditioning is to provide a comfortable, healthy, and productive indoor environment while also saving energy and reducing environmental impact.
In medical terms, air conditioning can be particularly important in healthcare settings such as hospitals and clinics, where maintaining proper temperature and humidity levels is essential for the health and well-being of patients and staff. Proper air conditioning can help prevent the growth of bacteria, viruses, and mold, reduce the spread of airborne particles, and minimize the risk of infection and illness.
Air conditioning systems in healthcare facilities may include specialized components such as HEPA filters, UV germicidal irradiation, and humidity control to provide a higher level of air quality and protection against infectious diseases. Regular maintenance and testing of these systems is also critical to ensure their proper functioning and to maintain a safe and healthy indoor environment.
Heat exhaustion is a condition characterized by excessive loss of water and salt, typically through heavy sweating, leading to physical symptoms such as weakness, dizziness, cool moist skin with goose bumps when in a hot environment, and a rapid, weak pulse. It can also cause nausea, headache, and fainting. Heat exhaustion is less severe than heat stroke but should still be treated as a medical emergency to prevent progression to the more serious condition. The primary treatment for heat exhaustion includes restoring water and salt balance through oral or intravenous rehydration, cooling the body with cold compresses or a cool bath, and removing the person from the hot environment.
Ventilation, in the context of medicine and physiology, refers to the process of breathing, which is the exchange of air between the lungs and the environment. It involves both inspiration (inhaling) and expiration (exhaling). During inspiration, air moves into the lungs, delivering oxygen to the alveoli (air sacs) where gas exchange occurs. Oxygen is taken up by the blood and transported to the body's cells, while carbon dioxide, a waste product, is expelled from the body during expiration.
In a medical setting, ventilation may also refer to the use of mechanical devices, such as ventilators or respirators, which assist or replace the breathing process for patients who are unable to breathe effectively on their own due to conditions like respiratory failure, sedation, neuromuscular disorders, or injuries. These machines help maintain adequate gas exchange and prevent complications associated with inadequate ventilation, such as hypoxia (low oxygen levels) and hypercapnia (high carbon dioxide levels).
Air microbiology is the study of microorganisms, such as bacteria, fungi, and viruses, that are present in the air. These microorganisms can be suspended in the air as particles or carried within droplets of liquid, such as those produced when a person coughs or sneezes.
Air microbiology is an important field of study because it helps us understand how these microorganisms are transmitted and how they may affect human health. For example, certain airborne bacteria and fungi can cause respiratory infections, while airborne viruses can cause diseases such as the common cold and influenza.
Air microbiology involves various techniques for collecting and analyzing air samples, including culturing microorganisms on growth media, using molecular biology methods to identify specific types of microorganisms, and measuring the concentration of microorganisms in the air. This information can be used to develop strategies for controlling the spread of airborne pathogens and protecting public health.
In the context of medical terminology, "heating" generally refers to the application of heat to an area of the body for therapeutic purposes. This can be done using various methods such as hot packs, heating pads, warm compresses, or even heated wax. The goal of applying heat is to increase blood flow, reduce pain and muscle spasms, and promote healing in the affected area. It's important to note that excessive heating or application of heat to sensitive areas should be avoided, as it can lead to burns or other injuries.
Indoor air pollution refers to the contamination of air within buildings and structures due to presence of particles, gases, or biological materials that can harmfully affect the health of occupants. These pollutants can originate from various sources including cooking stoves, heating systems, building materials, furniture, tobacco products, outdoor air, and microbial growth. Some common indoor air pollutants include particulate matter, carbon monoxide, nitrogen dioxide, sulfur dioxide, volatile organic compounds (VOCs), and mold. Prolonged exposure to these pollutants can cause a range of health issues, from respiratory problems to cancer, depending on the type and level of exposure. Effective ventilation, air filtration, and source control are some of the strategies used to reduce indoor air pollution.
I believe there might be a bit of confusion in your question as "automobiles" is a general term used to describe wheeled motor vehicles for transportation, and it's not typically a medical term with its own specific definition. However, I can provide you with some automobile-related terms that have medical implications:
1. **Driving fitness**: This refers to the physical and mental abilities required to operate a vehicle safely. Various medical conditions or treatments can impact driving fitness, such as seizure disorders, sleep apnea, certain medications, or alcohol/substance use disorders.
2. **Driving simulator**: A device used in research and rehabilitation settings that presents a realistic driving environment for assessing and training individuals with various medical conditions or disabilities affecting their ability to drive.
3. **Adaptive automobile equipment**: Devices designed to assist people with disabilities in operating vehicles, such as hand controls, wheelchair lifts, or pedal extensions.
4. **Transportation disadvantage**: A situation where an individual's medical condition, disability, or lack of access to suitable transportation limits their ability to obtain necessary healthcare services.
5. **Motor vehicle crash (MVC) outcomes**: Medical consequences resulting from motor vehicle crashes, including injuries and fatalities. These outcomes are often studied in public health and injury prevention research.
If you have a specific medical term or concept related to automobiles that you would like me to define or explain, please provide more details, and I will be happy to help.
Classical conditioning is a type of learning process that occurs when two stimuli are repeatedly paired together, leading to an association between them. This concept was first introduced by Ivan Pavlov, a Russian physiologist, in his studies on classical conditioning in the late 19th and early 20th centuries.
In classical conditioning, there are typically two types of stimuli involved: the unconditioned stimulus (US) and the neutral stimulus (NS). The US is a stimulus that naturally triggers a response, known as the unconditioned response (UR), in an organism. For example, food is an US that triggers salivation, which is the UR, in dogs.
The NS, on the other hand, is a stimulus that does not initially trigger any response in the organism. However, when the NS is repeatedly paired with the US, it becomes a conditioned stimulus (CS) and begins to elicit a conditioned response (CR). The CR is similar to the UR but is triggered by the CS instead of the US.
For example, if Pavlov repeatedly rang a bell (NS) just before presenting food (US) to a dog, the dog would eventually start salivating (CR) in response to the bell (CS) even when food was not presented. This is an example of classical conditioning.
Classical conditioning has been widely studied and is believed to play a role in various physiological processes, such as learning, memory, and emotion regulation. It has also been used in various applications, including behavioral therapy and advertising.
In medical terms, 'air' is defined as the mixture of gases that make up the Earth's atmosphere. It primarily consists of nitrogen (78%), oxygen (21%), and small amounts of other gases such as argon, carbon dioxide, and trace amounts of neon, helium, and methane.
Air is essential for human life, as it provides the oxygen that our bodies need to produce energy through respiration. We inhale air into our lungs, where oxygen is absorbed into the bloodstream and transported to cells throughout the body. At the same time, carbon dioxide, a waste product of cellular metabolism, is exhaled out of the body through the lungs and back into the atmosphere.
In addition to its role in respiration, air also plays a critical role in regulating the Earth's climate and weather patterns, as well as serving as a medium for sound waves and other forms of energy transfer.
Eyelid conditioning, also known as eyelid classical conditioning or Ursinus' phenomenon, is a type of reflex conditioning that involves associating a neutral stimulus with the natural act of blinking. This concept was first described by Russian physiologist Ivan Pavlov and later studied in detail by German ophthalmologist Hermann Ludwig Ferdinand von Helmholtz and Austrian physician Sigmund Exner.
In this procedure, a conditioned stimulus (like a sound or light) is repeatedly presented just before the unconditioned stimulus (such as a puff of air directed at the eye), which naturally triggers the blink reflex. Over time, the subject begins to associate the conditioned stimulus with the blinking response and will start to blink even when only the conditioned stimulus is presented, without the presence of the unconditioned stimulus. This learning process is an example of classical conditioning and can be used in various research and clinical applications.
In a medical context, "hot temperature" is not a standard medical term with a specific definition. However, it is often used in relation to fever, which is a common symptom of illness. A fever is typically defined as a body temperature that is higher than normal, usually above 38°C (100.4°F) for adults and above 37.5-38°C (99.5-101.3°F) for children, depending on the source.
Therefore, when a medical professional talks about "hot temperature," they may be referring to a body temperature that is higher than normal due to fever or other causes. It's important to note that a high environmental temperature can also contribute to an elevated body temperature, so it's essential to consider both the body temperature and the environmental temperature when assessing a patient's condition.
Environmental exposure refers to the contact of an individual with any chemical, physical, or biological agent in the environment that can cause a harmful effect on health. These exposures can occur through various pathways such as inhalation, ingestion, or skin contact. Examples of environmental exposures include air pollution, water contamination, occupational chemicals, and allergens. The duration and level of exposure, as well as the susceptibility of the individual, can all contribute to the risk of developing an adverse health effect.
Transplantation conditioning, also known as preparative regimen or immunoablative therapy, refers to the use of various treatments prior to transplantation of cells, tissues or organs. The main goal of transplantation conditioning is to suppress the recipient's immune system, allowing for successful engraftment and minimizing the risk of rejection of the donor tissue.
There are two primary types of transplantation conditioning: myeloablative and non-myeloablative.
1. Myeloablative conditioning is a more intensive regimen that involves the use of high-dose chemotherapy, radiation therapy or both. This approach eliminates not only immune cells but also stem cells in the bone marrow, requiring the recipient to receive a hematopoietic cell transplant (HCT) from the donor to reconstitute their blood and immune system.
2. Non-myeloablative conditioning is a less intensive regimen that primarily targets immune cells while sparing the stem cells in the bone marrow. This approach allows for mixed chimerism, where both recipient and donor immune cells coexist, reducing the risk of severe complications associated with myeloablative conditioning.
The choice between these two types of transplantation conditioning depends on various factors, including the type of transplant, patient's age, overall health, and comorbidities. Both approaches carry risks and benefits, and the decision should be made carefully by a multidisciplinary team of healthcare professionals in consultation with the patient.
Fear is a basic human emotion that is typically characterized by a strong feeling of anxiety, apprehension, or distress in response to a perceived threat or danger. It is a natural and adaptive response that helps individuals identify and respond to potential dangers in their environment, and it can manifest as physical, emotional, and cognitive symptoms.
Physical symptoms of fear may include increased heart rate, rapid breathing, sweating, trembling, and muscle tension. Emotional symptoms may include feelings of anxiety, worry, or panic, while cognitive symptoms may include difficulty concentrating, racing thoughts, and intrusive thoughts about the perceived threat.
Fear can be a normal and adaptive response to real dangers, but it can also become excessive or irrational in some cases, leading to phobias, anxiety disorders, and other mental health conditions. In these cases, professional help may be necessary to manage and overcome the fear.