GLOSSARY

Small amounts are required for a healthy diet, but higher amounts may cause neurological damage.

A naturally-occurring poisonous metal element which occurs naturally in the earth's surface.

Enters groundwater and surface water by dissolution of rocks and soils, from atmospheric fallout and biological decays and waste disposal.

A chemical that is required for metabolic processes, which must be taken from food or another external source. Macronutrients taken from food sources include carbohydrates, proteins, fats and vitamins.

A lipid, any of a diverse group of organic compounds including fats, oils, hormones and certain components of membranes that are grouped together because they do not interact appreciably with water, combined chemically with oxygen.

Vegetable oils that have been hydrogenated or partially hydrogenated for the purpose of being solid at room-temperature, which contain trans-fats.

A family of fluorine-containing chemicals with unique properties to make materials stain- and stick-resistant.

A former commercially produced synthetic organic chemical compound that may be present in products and materials produced before the 1979 PCB ban.

A synthetic resin used chiefly in paints and varnishes. Diisocyanates in polyurethane products can be toxic if inhaled or touched during installation.

Radioactive, carcinogenic noble gas generated from the decay of natural deposits of uranium.

Neurotransmitter hormone produced in the gut and brain stem which regulates mood, sleep and digestion.

Sodium is consumed as sodium chloride in common salt. It is a vital nutrient, but unhealthy in high amounts.

A chlorinated hydrocarbon used as a dry cleaning solvent, an additive in textile processing and metal degreasing that has been linked to cancer.

A poisonous substance produced by a living organism.

Also called nanoparticles, ultrafine particles are a subcategory of PM₂.₅ which are exclusively less than 0.1 µm. Due to the small size they are often airborne and can easily reach the alveoli of the lungs.

Organic, and therefore carbon and hydrogen containing, materials which evaporate and diffuse easily at ambient temperature. VOCs are emitted by a wide array of building materials, paints and common consumer products.

Acoustic decibel modified using "A-weighting" to adjust the frequency-dependent response of human hearing.

Percentage of space in which the light level from direct sun alone exceeds a pre-defined threshold (such as 1000 lux) for some quantity of hours (such as 250) in a year.

Clothing insulation is the resistance to heat transfer provided by clothing measured in clo (1 clo = 0.155 m²K/W = 0.88°F ft²h/BTU).

Spectral distribution of electromagnetic radiation of a blackbody at a given temperature. For example, the color temperature during the daytime is approximately 15,000 K, while during sunset is approximately 1,850 K.

A unit of measurement for sound. The decibel is a logarithmic unit so an increase in 10 decibels equals an increase by a factor of 10.

The time averaged sound pressure level on the A-weighted scale, converted to decibels.

Unit of illuminance, equivalent to one lumen per square foot.

Amount of light passing through a given area in space. Measured in lux or foot-candles.

Rating from 0 (black) to 100 (white) describing the amount of visible and usable light that reflects from (or absorbs into) a painted surface.

Measurement of how bright a surface or light source will appear to the eye. Measured in candela/m² or foot-lamberts.

Radiant power weighted to human vision, describing light emitted by a source in a particular direction. Measured by the candela.

Concentration of a substance in drinking water believed to result in no adverse effects. Derived from on Population Adjusted Dose and estimated daily water consumption, fraction of exposure from water and body weight.

The uniform surface temperature of an imaginary black enclosure in which an occupant would gain or lose the same amount of radiant heat as in the actual non-uniform space; MRT is a primary driver of human thermal comfort, roughly equal in influence to air temperature.

Roughness rating of a physical surface, averaged in micro-meters & micro-inches.

Value assigned to an air filter to describe the amount of different types of particles removed when operating at the least effective point in its life.

Define the sound pressure limits of the octave band spectra ranging from 63-8000 Hz. The noise criteria equals the lowest curve which is not exceeded in the spectrum.

Average value that determines the absorptive properties of materials.

A unit of measurement to express very dilute concentrations of substances.

Ratio of partial pressure of water vapor in the air to the saturation pressure of water vapor at the same temperature and pressure.

Sound pressure level (SPL), also known as acoustic pressure, is the pressure variation associated with sound waves. Usually measured in decibels, the acoustic pressure is a ratio between the measured value and a reference value; a common reference is threshold of hearing or the minimum sound level that the average person can hear.

Percentage of floor space where a minimum light level (for example 300 lux) can be met completely for some proportion (for example 50%) of regular operating hours by natural light.

A measurement that takes into account a building inhabitants’ physical output; it is recommended a building obtains a Walk Score® of 70 or greater.

The concentration of an air pollutant (e.g. ozone) is given in micrograms (one-millionth of a gram) per cubic meter air or µg/m3.