Maximum Allowable Concentration: The maximum exposure to a biologically active physical or chemical agent that is allowed during an 8-hour period (a workday) in a population of workers, or during a 24-hour period in the general population, which does not appear to cause appreciable harm, whether immediate or delayed for any period, in the target population. (From Lewis Dictionary of Toxicology, 1st ed)ColoradoParticulate Matter: Particles of any solid substance, generally under 30 microns in size, often noted as PM30. There is special concern with PM1 which can get down to PULMONARY ALVEOLI and induce MACROPHAGE ACTIVATION and PHAGOCYTOSIS leading to FOREIGN BODY REACTION and LUNG DISEASES.Trustees: Board members of an institution or organization who are entrusted with the administering of funds and the directing of policy.United States Food and Drug Administration: An agency of the PUBLIC HEALTH SERVICE concerned with the overall planning, promoting, and administering of programs pertaining to maintaining standards of quality of foods, drugs, therapeutic devices, etc.Equipment Safety: Freedom of equipment from actual or potential hazards.Device Approval: Process that is gone through in order for a device to receive approval by a government regulatory agency. This includes any required preclinical or clinical testing, review, submission, and evaluation of the applications and test results, and post-marketing surveillance. It is not restricted to FDA.Air Pollutants: Any substance in the air which could, if present in high enough concentration, harm humans, animals, vegetation or material. Substances include GASES; PARTICULATE MATTER; and volatile ORGANIC CHEMICALS.Papilledema: Swelling of the OPTIC DISK, usually in association with increased intracranial pressure, characterized by hyperemia, blurring of the disk margins, microhemorrhages, blind spot enlargement, and engorgement of retinal veins. Chronic papilledema may cause OPTIC ATROPHY and visual loss. (Miller et al., Clinical Neuro-Ophthalmology, 4th ed, p175)Cerebrospinal Fluid Pressure: Manometric pressure of the CEREBROSPINAL FLUID as measured by lumbar, cerebroventricular, or cisternal puncture. Within the cranial cavity it is called INTRACRANIAL PRESSURE.Scotoma: A localized defect in the visual field bordered by an area of normal vision. This occurs with a variety of EYE DISEASES (e.g., RETINAL DISEASES and GLAUCOMA); OPTIC NERVE DISEASES, and other conditions.Refraction, Ocular: Refraction of LIGHT effected by the media of the EYE.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Visual Acuity: Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.Hyperopia: A refractive error in which rays of light entering the eye parallel to the optic axis are brought to a focus behind the retina, as a result of the eyeball being too short from front to back. It is also called farsightedness because the near point is more distant than it is in emmetropia with an equal amplitude of accommodation. (Dorland, 27th ed)Infant Food: Food processed and manufactured for the nutritional health of children in their first year of life.Spain: Parliamentary democracy located between France on the northeast and Portugual on the west and bordered by the Atlantic Ocean and the Mediterranean Sea.Vegetables: A food group comprised of EDIBLE PLANTS or their parts.Nitrate Reductase: An enzyme that catalyzes the oxidation of nitrite to nitrate. It is a cytochrome protein that contains IRON and MOLYBDENUM.Citrus sinensis: A plant species of the genus CITRUS, family RUTACEAE that provides the familiar orange fruit which is also a source of orange oil.Nitrates: Inorganic or organic salts and esters of nitric acid. These compounds contain the NO3- radical.Dental Service, Hospital: Hospital department providing dental care.Stress, Mechanical: A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins: SNARE binding proteins that facilitate the ATP hydrolysis-driven dissociation of the SNARE complex. They are required for the binding of N-ETHYLMALEIMIDE-SENSITIVE PROTEIN (NSF) to the SNARE complex which also stimulates the ATPASE activity of NSF. They are unrelated structurally to SNAP-25 PROTEIN.Pharmacopoeias as Topic: Authoritative treatises on drugs and preparations, their description, formulation, analytic composition, physical constants, main chemical properties used in identification, standards for strength, purity, and dosage, chemical tests for determining identity and purity, etc. They are usually published under governmental jurisdiction (e.g., USP, the United States Pharmacopoeia; BP, British Pharmacopoeia; P. Helv., the Swiss Pharmacopoeia). They differ from FORMULARIES in that they are far more complete: formularies tend to be mere listings of formulas and prescriptions.Waste Products: Debris resulting from a process that is of no further use to the system producing it. The concept includes materials discharged from or stored in a system in inert form as a by-product of vital activities. (From Webster's New Collegiate Dictionary, 1981)Waste Management: Disposal, processing, controlling, recycling, and reusing the solid, liquid, and gaseous wastes of plants, animals, humans, and other organisms. It includes control within a closed ecological system to maintain a habitable environment.Industrial Waste: Worthless, damaged, defective, superfluous or effluent material from industrial operations.Medical Waste: Blood, mucus, tissue removed at surgery or autopsy, soiled surgical dressings, and other materials requiring special disposal procedures.South CarolinaReproductive Techniques, Assisted: Clinical and laboratory techniques used to enhance fertility in humans and animals.Explosive Agents: Substances that are energetically unstable and can produce a sudden expansion of the material, called an explosion, which is accompanied by heat, pressure and noise. Other things which have been described as explosive that are not included here are explosive action of laser heating, human performance, sudden epidemiological outbreaks, or fast cell growth.Term Birth: CHILDBIRTH at the end of a normal duration of PREGNANCY, between 37 to 40 weeks of gestation or about 280 days from the first day of the mother's last menstrual period.Lead PoisoningRadon: A naturally radioactive element with atomic symbol Rn, atomic number 86, and atomic weight 222. It is a member of the noble gas family found in soil, and is released during the decay of radium.Environmental Health: The science of controlling or modifying those conditions, influences, or forces surrounding man which relate to promoting, establishing, and maintaining health.IndianaUnited Nations: An international organization whose members include most of the sovereign nations of the world with headquarters in New York City. The primary objectives of the organization are to maintain peace and security and to achieve international cooperation in solving international economic, social, cultural, or humanitarian problems.Nitrogen Oxides: Inorganic oxides that contain nitrogen.Conservation of Natural Resources: The protection, preservation, restoration, and rational use of all resources in the total environment.Sulfur Dioxide: A highly toxic, colorless, nonflammable gas. It is used as a pharmaceutical aid and antioxidant. It is also an environmental air pollutant.Phthalic Acids: A group of compounds that has the general structure of a dicarboxylic acid-substituted benzene ring. The ortho-isomer is used in dye manufacture. (Dorland, 28th ed)Plasticizers: Materials incorporated mechanically in plastics (usually PVC) to increase flexibility, workability or distensibility; due to the non-chemical inclusion, plasticizers leach out from the plastic and are found in body fluids and the general environment.Diethylhexyl Phthalate: An ester of phthalic acid. It appears as a light-colored, odorless liquid and is used as a plasticizer for many resins and elastomers.Minor Planets: Small solar system planetary bodies including asteroids. Most asteroids are found within the gap lying between the orbits of Mars and Jupiter.Dibutyl Phthalate: A plasticizer used in most plastics and found in water, air, soil, plants and animals. It may have some adverse effects with long-term exposure.EstersBenzoflavones: Organic compounds containing a BENZENE ring attached to a flavone group. Some of these are potent arylhydrocarbon hydroxylase inhibitors. They may also inhibit the binding of NUCLEIC ACIDS to BENZOPYRENES and related compounds. The designation includes all isomers; the 7,8-isomer is most frequently encountered.Biosensing Techniques: Any of a variety of procedures which use biomolecular probes to measure the presence or concentration of biological molecules, biological structures, microorganisms, etc., by translating a biochemical interaction at the probe surface into a quantifiable physical signal.Flow Injection Analysis: The analysis of a chemical substance by inserting a sample into a carrier stream of reagent using a sample injection valve that propels the sample downstream where mixing occurs in a coiled tube, then passes into a flow-through detector and a recorder or other data handling device.Circadian Rhythm: The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs and stimuli, hormone secretion, sleeping, and feeding.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Immunoassay: A technique using antibodies for identifying or quantifying a substance. Usually the substance being studied serves as antigen both in antibody production and in measurement of antibody by the test substance.Calibration: Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.Health Resorts