Absorbance (Abs)
Light absorption is a way to measure elemental carbon in samples. It is calculated by measuring the amount of light reflected by the particulates on the sample filters. The elemental carbon results on the NYC Tracking Portal are displayed as units of absorbance (abs).

Acute health effect

An adverse effect occurring within hours or days that may result from exposure to certain contaminants, for example, dizziness and headache resulting from carbon monoxide poisoning. Symptoms often subside after the exposure stops.

A group of chemicals that are produced by a mold. Aflatoxins sometimes contaminate certain foods.

Age-adjusted rates
Most health outcomes - cancers or heart disease, for example - occur at different rates in different age groups. A neighborhood with a high proportion of older people would be expected to have a higher rate of heart disease based on its age makeup alone. Age-adjustment minimizes the impact of age differences when comparing two rates. It allows for the conclusion that differences in rates between two places are probably due to factors other than age. Within the Tracking Portal, all age-adjusted rates have been standardized to the Year 2000 U.S. Census Population.

Air Pollutant
Any substance in air that could, in high enough concentration, harm people, other animals, vegetation, or material. Pollutants include almost any type of natural or artificial matter capable of being airborne, taking the form of solid particles, liquid droplets, gases, or a mixture of all three forms.

Air Quality Index (AQI)
An index for reporting daily air quality based on multiple pollutants. It provides information on how clean or polluted air is, and the degree to which associated health effects might be a concern. The AQI focuses on acute health effects that may be experienced within a few hours or days after breathing polluted air. The higher the AQI value, the more likely people are to experience related health effects, especially sensitive populations.

Air Quality System (AQS)
A national database that contains ambient air pollution data collected by EPA, state, local, and tribal air pollution control agencies from thousands of monitoring stations.

Surrounding. Ambient air is usually outdoor air (as opposed to indoor air).

A birth defect where there is an absence of the skull, with cerebral hemispheres completely missing or reduced to small masses attached to the base of the skull; this condition is not compatible with life. Anencephaly is one type of neural tube defect.

Arsenic is a toxic element that occurs naturally in the environment and is also a byproduct of some industrial activities.


Asthma is a lung disease which results in shortness of breath, coughing, chest tightness, or wheezing. Asthma attacks and symptoms can be triggered or made worse by exposure to air pollution, tobacco smoke, pollen, cockroaches, mold, and pets. Asthma cannot be cured, but it can be controlled. 

The measurement of chemicals (or their metabolites) in a person’s body fluids or tissues, such as blood or urine. It tells us the amount of the chemical that actually gets into people from all sources (for example, from air, soil, water, dust, and food) combined.

Birth weight
The first weight of a newborn after birth.

Blood Lead Level (BLL)
A measure of lead in the body. It is measured in micrograms of lead per deciliter of blood (µg/dL).

Carbon monoxide
A colorless, odorless, poisonous gas produced by incomplete combustion of fossil fuels.

Any substance that can cause or aggravate cancer.

Chlorpyrifos is a broad-spectrum organophosphate insecticide. Since 2000, chlorpyrifos is no longer permitted to be used for structural (household and building) pest control.

Cholinesterase Inhibitors
Some pesticides act as cholinesterase inhibitors. Cholinesterase is an enzyme that helps regulate the neurotransmitter acetylcholine. Acetylcholine helps transfer nerve impulses from a nerve cell to a muscle cell or another nerve cell. If acetylcholine is not properly controlled by cholinesterase, the nerve impulses or neurons remain active longer than they should, over-stimulating the nerves and muscles. This can cause symptoms such as weakness or paralysis of the muscles.

Chronic health effect
A health condition that develops and persists over a long period of time.

Clean Air Act
The federal law that defines EPA's responsibilities for protecting and improving the nation's air quality and the stratospheric ozone layer. The Act empowers EPA to set limits on the amount of different pollutants allowed in the air anywhere in the United States, known as National Ambient Air Quality Standards (NAAQS).

Cleft Lip (with or without Cleft Palate)
Refers to a birth defect where there is failure of the fetal components of the lip to fuse or join, forming a groove or fissure in the lip.

Cleft Palate
A birth defect where there is failure of the palate to fuse properly, forming a grooved depression or fissure in the roof of the mouth. This defect varies in degree of severity. The fissure can extend into the hard and soft palate and into the nasal cavities.

Cockroach chalk
An illegal pesticide product often used for controlling cockroaches. Also called “Miracle Chalk”, and sometimes “Chinese Chalk” because so many of these illegally imported products are lettered with Chinese characters

Community Water System (CWS)
A public water system that supplies water to the same population year-round.

A substance or material that is present in an environment where it does not belong.

Statistical measure of the degree to which two variables change together. For example, Emergency Room visits resulting from asthma increase when ozone air pollution increases. Correlation alone is not evidence for a cause and effect relationship.

A drying agent sometimes used in pesticide products.

Diazinon is the common name of an organophosphorus pesticide used to control pest insects in soil, on ornamental plants, and on fruit and vegetable field crops. Sales of home and garden products containing diazinon ceased in the U.S. in 2004.

Disease Coding Practices
Health information coding (called “disease coding” in the portal) is the transformation of verbal descriptions of diseases, injuries, and procedures into numeric or alphanumeric designations. Originally, medical coding was performed to classify mortality (cause of death) data on death certificates. However, coding is also used to classify illness and disease and procedural data. The coding of health-related data permits access to medical records by diagnoses and procedures for use in clinical care, research, and education.

Disinfection byproducts (DBP)
A family of chemicals formed when disinfectants, such as chlorine, react with naturally occurring organic matter and other substances in source water. DBPs include haloacetic acids (HAA5) and trihalomethanes (THM).

Down Syndrome (Trisomy 21)
A birth defect with chromosomal abnormality characterized by an extra copy of chromosome 21. Down syndrome is characterized by moderate to severe mental retardation, sloping forehead, small ear canals, flat bridged nose and short fingers and toes.

Ecological Study
An ecological study is an epidemiologic study in which the unit of analysis is the population rather than the individual. Ecologic variables are summary characteristics of groups, organizations, or places. Errors in inferring cause and effect associations may result with ecological analyses, because observations from a group-level analysis may not reflect effects at an individual level.

Elemental carbon (EC)
Also known as black carbon,EC is a component of particulate matter. EC is produced in the combustion of fuels, and diesel exhaust is an important source.

Environmental Intervention Blood Lead Level (EIBLL)
Environmental Intervention Blood Lead Level (EIBLL) is the BLL at which the NYC Department of Health and Mental Hygiene Lead Poisoning Prevention Program provides case coordination and environmental intervention to lead-poisoned children. Since August 2004, the EIBLL has been defined as a BLL = 15 µg/dL.

Environmental Public Health Tracking (EPHT)
Environmental Public Health Tracking is the ongoing, systematic collection, integration, analysis, interpretation, and dissemination of data from environmental hazard monitoring, and from human exposure and health effects surveillance.

Environmentally Persistent
A chemical compound that does not rapidly break down but remains in the environment for a prolonged period.

EPA (Environmental Protection Agency)

The Environmental Protection Agency is an agency of the United States federal government charged with administering federal environment laws. 

The study of the distribution and determinants of health-related states or events in a population.

Esophagus Cancer
Cancer that affects the muscular tube that leads from the larynx to the stomach.

Actual conception and birth, as opposed to fecundity, which is the potential ability to bear a child and bring it to term. Fertility is often measured by the rate of childbirth in a population.

A developing mammal. In humans, the fetal stage of prenatal development begins about eight weeks after fertilization, when the major structures and organ systems have formed, and lasts until birth.

Fine particulate matter
Air particles, such as those found in smoke and haze, that are 2.5 micrometers in diameter and smaller.

Fire Department of NYC (FDNY)
Refers to the Fire Department of NYC. See “About the Data” for more information.

A pesticide used to control the growth of fungus and molds.

A birth defect where there is an opening of the abdominal wall with protrusion of the intestines.

Geographic Information Systems (GIS)
A computer-based software system that enables the creation, analysis and application of geographic data or other information linked to specific locations on a map.

The carrying of young in the uterus.

Ground level ozone (also called Ozone)
A gas composed of three oxygen atoms. Ozone is not usually emitted directly into the air, but at ground-level is created by a chemical reaction between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. Ozone has the same chemical structure whether it occurs miles above the earth or at ground-level and can be "good" or "bad," depending on its location in the atmosphere. In the earth's lower atmosphere, ground-level ozone is considered "bad." Motor vehicle exhaust and industrial emissions, gasoline vapors, and chemical solvents as well as natural sources emit NOx and VOC that help form ozone. Ground-level ozone is the primary constituent of smog. Sunlight and hot weather cause ground-level ozone to form in harmful concentrations in the air. As a result, it is known as a summertime air pollutant.

Health effect or health outcome
A disease, condition or symptoms of illness.

A pesticide used to kill or control undesirable plants (generally considered weeds).

Hypoplastic Left Heart Syndrome
A birth defect that occurs when the left side of the heart— including the aorta, aortic valve, left ventricle and mitral valve—is underdeveloped. This condition is usually fatal in the first month of life if not treated.

A birth defect in which the urinary outlet is on the underside of the penis or on the perineum (area between the genitals and the anus).

Number of new cases of illness occurring within a population over a specified period of time.

Public health indicators provide information about a population’s health status. As part of the nationwide EPHT network implementation, work groups developed environmental public health indicators and measures. Guidelines were established for the collection of data and the calculation of measures in a nationally-consistent way.

Infant mortality
Deaths among children under one year of age.

Integrated Pest Management (IPM)
An environmentally sensitive approach to pest management that uses current, comprehensive information on the life cycles of pests and their interaction with the environment to emphasize prevention, rather than a pesticide-dependent response to the presence of pests.

Intercensal estimates
Estimates of neighborhood populations produced by the NYC Health Department. The estimates are based on the US Census Bureau Population Estimate Program and housing unit data obtained from the NYC Dept of City Planning (DCP). At the borough and city levels, these estimates are identical to the US Census Bureau Intercensal Population Estimates, as challenged by NYC DCP.

International Classification of Diseases (ICD)
A system produced by an internationally representative group that classifies diseases by giving each a unique code.

Land Use Regression (LUR)
A statistical modeling technique that examines the geographic relationship between air pollution measurements collected across an urban area and distributed sources, such as traffic, buildings or land-use type.

Larynx Cancer
Also called laryngeal cancer, this is a cancer of the larynx, which is part of the throat below the pharynx and above the esophagus. Tobacco use (either through smoking or chewing) raises one's risk of this type of cancer.

Latency period
The period of time between exposure to something that causes a disease and the onset of the health effect.

Lead Poisoning Prevention Program (LPPP)
A program at the NYC Department of Health and Mental Hygiene (the Health Department) whose mission is to prevent and control childhood lead poisoning.

Cancer that starts in blood-forming tissue, such as the bone marrow, and causes large numbers of blood cells to be produced and enter the bloodstream. In most types of leukemia, the abnormal cells are white blood cells. Leukemia cells look different from normal blood cells and do not work as they should.

The most common types of leukemia are:

  • acute lymphocytic leukemia (ALL) – the most common type of leukemia in children. It also affects adults, especially those age 65 and older.
  • acute myeloid leukemia (AML) – this disease occurs in both adults and children and is sometimes called acute non-lymphocytic leukemia.
  • chronic lymphocytic leukemia (CLL) – this disease most commonly affects adults over age 55 and rarely occurs in children.
  • chronic myeloid leukemia (CML) – this disease occurs mainly in adults, but a small number of children also get this form of leukemia.

Low Birthweight at Term
A baby is considered low birth weight when it weighs less than 5.5 lbs (2500 grams) at birth. In the EPHT Network, low birth weight is being used as a marker for fetal growth retardation.

Low-density lipoprotein (LDL)
A type of cholesterol measured in blood. LDL can clog arteries, increasing the risk of heart disease.

Lower Limb Deficiencies (Congenital Amputation, Proximal Femoral Focal Deficiency)
A birth defect where a portion of the lower limb is absent.

Material Safety Data Sheets (MSDS)
A standard set of information provided by the manufacturer of a product for the proper storage and use of a chemical, including toxicity and safety information.

Abbreviation for Maximum Contaminant level. The highest level of a substance allowed in drinking water by the U.S. Environmental Protection Agency, intended to protect people from adverse health effects of contaminants.

On the Tracking Network, a measure is a summary characteristic or statistic, such as a sum, percentage, or rate. Measures are available for each indicator.

The rarest but most serious of skin cancers. Data reported in the NYC Tracking Portal are for invasive melanoma of the skin only, although there are other types of melanoma and other parts of the body where melanoma can develop.

Metadata is a set of information that describes each source of data on the EPHT Portal, including publishing organization, purpose, access, quality, and date range available. Users can use key words to search Metadata to find out what data sources are available on the Portal and to learn more about them.

Localized climate conditions within an urban area or neighborhood. For example, a microclimate could occur around a stand of trees.


A microscopic organism, including bacteria, viruses, and protozoans, that can often contaminate food and water. The majority of microorganisms are typically harmless, but infectious ones present in some drinking water have the tendency of multiplying in the human body, causing disease. Water treatment plants usually rid water of most microorganisms, however it is possible for the water to not be completely free of microorganisms. 

National Ambient Air Quality Standards
The federal Clean Air Act requires the U.S. EPA to set standards for “criteria pollutants”—six commonly occurring air pollutants. These standards, known as the National Ambient Air Quality Standards (NAAQS), are national targets for acceptable concentrations of each of the criteria pollutants. The Standards apply to outdoor air throughout the country.

Neonatal mortality
Deaths among children from birth up to but not including 28 days of age.

Nickel (Ni)
Nickel is one of several metals that are found in particulates released from the combustion of residual heating fuel.

Drinking water contaminants composed of nitrogen and oxygen. Nitrates can come from fertilizers, animal waste and failed septic systems.

Nitrogen oxides (NOx)
The group of gases composed of only nitrogen and oxygen, including nitrogen dioxide (NO2) and nitric oxide (NO), gaseous compounds formed by combustion.

Non-Hodgkin lymphoma
Lymphoma is the name for cancers that develop in the lymphatic system, a part of the body's immune system. Lymphomas are often divided into two groups: Hodgkin lymphoma and non-Hodgkin lymphoma. Nationally, non-Hodgkin lymphoma is the sixth most common site of new cancer diagnoses among men and fifth among women. Approximately 70% of people diagnosed with non-Hodgkin lymphoma are age 50 and over.

NYC Department of Environmental Protection (DEP)
The NYC Agency that manages the city’s drinking water supply. See “About the Data” for more information.

NYC Poison Control Center (PCC)
Established in 1955, the NYC PCC is designated as a Regional Poison Control Center by the American Association of Poison Control Centers.

NYS Cancer Registry
A registry operated by the NYS Department of Health that collects, processes and reports on information about every New Yorker diagnosed with cancer. Because the Registry has been population-based since 1976, it can be used to monitor cancer incidence patterns in all of New York State.


New York City's plan to become the most resilient,  equitable, and sustainable city in the world. Proposed in 2007 under the name PlaNYC, OneNYC envisions how the city should be shaped to address social, economic, and enviornmental issues. The program is overseen by The Mayor's Office of Sustainability alongside the Mayor's Office of Recovery and Resiliency. 

Organophosphates are a class of insecticides used in agriculture and veterinary practice, and previously used in structural pest control. Organophosphates work by inhibiting an enzyme in the body called acetylcholinesterase. This enzyme is critical for controlling nerve signals in the body. The damage to this enzyme kills pests and may cause unwanted side effects in exposed humans. All organophosphates have a common mechanism of toxicity and can cause similar symptoms in humans who have too much exposure.

Orofacial clefts
see Cleft Lip and Cleft Palate.

Overweight & Obesity
Body Mass Index (BMI) is calculated based on respondents' self-reported weight and height. A BMI between 25.0 and 29.9 is classified as overweight, and a BMI of 30 or greater is classified as obese.

See Ground Level Ozone

Parkinson’s disease
A disorder that affects nerve cells, or neurons, in a part of the brain that controls muscle movement. The causes and contributors to Parkinson’s are subjects of intensive research. Parkinson's usually begins around age 60, but can start earlier. It is more common in men than in women. There is currently no cure for Parkinson's disease, but a variety of medicines can help to ameliorate symptoms.

Particulate Matter
Also known as particle pollution or PM, is a complex mixture of extremely small solid particles and mists. Particulate pollution is made up of a number of components, including acids (such as nitrates and sulfates), organic chemicals, metals, and soil or dust particles. Smaller particles of 10 micrometers in diameter or smaller more easily bypass the natural defenses of the body, and are more easily inhaled deep into lung tissue, where they can cause health problems.

Perinatal mortality
Fetal deaths combined with infant deaths that occur up to 6 days after birth. Fetal deaths are defined as those that occur at 28 or more weeks gestation.

Perinatal period
Refers to the period starting from 28 weeks of gestation and up to six days of life.

Pesticide (Herbicide / Insecticide / Fungicide / Rodenticide)
Any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest. Though often misunderstood to refer only to insecticides, the term pesticide also applies to herbicides, fungicides, and various other substances used to control pests. Under United States law, a pesticide is also any substance or mixture of substances intended for use as a plant regulator, defoliant, or desiccant.

The 127-point plan designed to create the first environmentally sustainable 21st century city unveiled by Mayor Michael R. Bloomberg in April, 2007. PlaNYC focuses on many facets of New York’s physical environment – its transportation network, housing stock, land and park system, energy network, water supply and air quality – and sets a course to achieve 10 aggressive goals to create a more sustainable New York by the year 2030.

Postneonatal mortality
Deaths among children from 28 days up to but not including 1 year of age.

Potable Water
Water for drinking and cooking.

Prenatal exposure
Exposure that occurs to the fetus during pregnancy (before birth). When a pregnant woman is exposed to any substance, situation or event, her unborn child may be exposed as well.

Proportion of individuals in a population at a given time who have a particular disease or health-related outcome.

Pesticides made of manufactured chemicals that are very similar in structure to the pyrethrins (naturally-occurring compounds with insecticidal properties that are found in pyrethrum extract from certain chrysanthemum flowers). Pyrethrins are often used in household insecticides and products to control insects on pets or livestock. More than 1,000 synthetic pyrethroids have been developed, but less than a dozen of them are currently used in the United States.

A measure of the frequency with which an event occurs in a defined population over a period of time.

Regression Line
A line that represents a “best fit” through a series of points on a graph. The lines depicted on the tracking portal are determined using a “least squares method,” which minimizes the sum of squared deviations of all points from the line. The slope of the regression line gives the unit increase in y for every unit increase in x. For example, a slope of 2.0 means that for every 1% increase in x, we can expect a 2% increase in y.

Renewable energy

Any naturally occurring energy source, that is not expended when used, for example, wind. Renewable energy sources help eliminate harmful fossil fuels, and can support a fruitful economy. In New York City, the most common renewable energy source is sunlight, followed by water (hydroelectric power). With an increase in the use of renewable energy sources throughout the world, the amount of pollution caused by fossil fuels will significantly decrease. 

Risk factor
An aspect of personal behavior or lifestyle, an environmental exposure, or a genetic characteristic that affects a person's chance of getting a disease or other adverse health effect.

A pesticide or any chemical used to kill rodents.

A graph that shows the relationship of one variable with another. Each point represents an entity (such as neighborhood), and its corresponding x and y values represent the values of variables (characteristics) that describe the entity.

The Safe Drinking Water Information System is a database designed by EPA to help states run their drinking water programs. SDWIS/NYS is the state counterpart to EPA's federal drinking water informat system.

Sex Ratio at Birth
The sex ratio at birth is the ratio of male to female births.

Singleton birth
The conception and birth of a single child in contrast to multiple births i.e., twins, triplets, etc.


The Statewide Planning and Research Cooperative System established in 1979 as a result of cooperation between the healthcare sector and the government. SPARCS collects data regarding hospital discharges, patient characteristics, diagnoses/treatments, and in and outpatient hospital care. 

Spina Bifida
A neural tube birth defect resulting from failure of the spinal neural tube to close. This usually results in damage to the spinal cord with paralysis of the involved limbs; includes myelomeningocele (involving both spinal cord and meninges) and meningocele (involving just the meninges).

Groups of NYC census tracts summing to at least 100,000 residents, determined by the NYC Department of Housing Preservation and Development. The boundaries of subborough areas often approximate those of NYC’s Community Districts. See a map of subborough neighborhoods (PDF).

Sudden Infant Death Syndrome (SIDS)
The sudden death of an infant less than one year of age that cannot be explained after a thorough investigation is conducted, including a complete autopsy, examination of the death scene, and review of the clinical history. SIDS is the leading cause of death among infants aged 1–12 months, and is the third leading cause overall of infant mortality in the United States.

Sulfur dioxide (SO2)
A gaseous pollutant formed by the combustion of fuels containing sulfur (e.g., coal, oil).

Tempo is the brand name of a registered pesticide in New York that is restricted in use and can only be sold and used by or under the supervision of a licensed pest control professional. The product when sold illegally on the streets and used contrary to label directions has been the cause of several poisonings in the home. The active ingredient Cyfluthrin is a potent insecticide that can be lethal to household pets and humans.

Tetralogy of Fallot
A cardiac birth anomaly consisting of four defects: ventricular septal defect, pulmonary valve stenosis or atresia, displacement of the aorta to the right, and hypertrophy of right ventricle. The condition is corrected surgically.

The NYC Community Air Survey (NYCCAS)
A local air quality study, part of PlaNYC, to measure street-level concentrations of combustion-related air pollutants shown to impact public health, at 150 locations throughout New York City, in each season of the year. NYCCAS is a collaborative effort among the NYC Department of Health and Mental Hygiene (DOHMH), City University of New York Queens College Center for the Biology of Natural Systems (CBNS) and ZevRoss Spatial Analysis.
NYC Health Department Community Health Surveys - A telephone survey conducted annually by the NYC Health Department's Division of Epidemiology, Bureau of Epidemiology Services. CHS provides robust data on the health of New Yorkers, including neighborhood, borough and citywide estimates on a broad range of chronic diseases and behavioral risk factors. CHS is modeled on the National Behavioral Risk Factor Surveillance System (BRFSS), conducted by the Centers for Disease Control and Prevention.

Traffic density

Traffic density is a measure of  the mean number of vehicles that occupy one mile, or kilometer. Travel time and traffic density (an indicator of congestion) can inform users about the state of a traffic system. 

Transposition of the Great Arteries
A birth defect in which the aorta arises from the right ventricle and the pulmonary artery from the left ventricle (opposite of normal), so that the venous return from the peripheral circulation is recirculated without being oxygenated in the lungs; immediate surgical correction is needed.

Tres pasitos
A pesticide illegally imported from Latin America primarily used for rodents and roaches. It typically contains the chemical aldicarb, which is a potent insecticide not approved for household use in the United States. Aldicarb can be poisonous to pets and humans. In Spanish, tres pasitos means “three little steps.”

A period of three months; especially one of the three three-month periods into which human pregnancy is divided.

The cloudy appearance of water caused by the presence of tiny particles. High levels of turbidity may interfere with proper water treatment and monitoring.

United Hospital Fund (UHF) Neighborhoods (34)
Consist of 34 adjoining zip code areas with similar characteristics. The grouping was developed for the Health Department’s annual Community Health Survey to increase the statistical power of the sample size by combining several of the UHF 42 neighborhoods. See a map of UHF 34 neighborhoods (PDF).

United Hospital Fund (UHF) Neighborhoods (42)
Consist of 42 adjoining zip code areas, designated by the United Hospital Fund - a non-profit health research organization - to approximate NYC Community Planning Districts. See a map of UHF 42 neighborhoods (PDF).

Upper Limb Deficiencies
A birth defect in which there is an absence of a portion of the upper limb.

US Census Bureau
The leading source of quality data about the nation's people and economy.

Vectorborne diseases

Diseases transmitted through the bite of an arthropod (insect, tick, mosquito, spider). 

Vital statistics
Data derived from certificates and reports of birth, death, fetal death, induced termination of pregnancy, marriage, and related reports.

Water quality criteria
Refers to levels of water quality expected to render a body of water suitable for its designated use. Criteria are based on specific levels of pollutants that would make the water harmful if used for drinking, swimming, farming, fish production, or industrial processes.

Zoonotic disease

Zoonotic diseases are disease transmitted from animals to humans through air, bites, or saliva.