Smog, or smoke fog, is a type of intense air pollution. The word "smog" was coined in the early 20th century, and is a portmanteau of the words smoke and fog to refer to smoky fog due to its opacity, and odor. The word was then intended to refer to what was sometimes known as pea soup fog, a familiar and serious problem in London from the 19th century to the mid-20th century, where it was commonly known as a London particular or London fog. This kind of visible air pollution is composed of nitrogen oxides, sulfur oxide, ozone, smoke and other particulates. Man-made smog is derived from coal combustion emissions, vehicular emissions, industrial emissions, forest and agricultural fires and photochemical reactions of these emissions.
Soot is a mass of impure carbon particles resulting from the incomplete combustion of hydrocarbons. It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolysed fuel particles such as coal, cenospheres, charred wood, and petroleum coke that may become airborne during pyrolysis and that are more properly identified as cokes or char.
Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline (petrol), diesel fuel, fuel oil, biodiesel blends, or coal. According to the type of engine, it is discharged into the atmosphere through an exhaust pipe, flue gas stack, or propelling nozzle. It often disperses downwind in a pattern called an exhaust plume.
Environmental toxicants and fetal development is the impact of different toxic substances from the environment on the development of the fetus. This article deals with potential adverse effects of environmental toxicants on the prenatal development of both the embryo or fetus, as well as pregnancy complications. The human embryo or fetus is relatively susceptible to impact from adverse conditions within the mother's environment. Substandard fetal conditions often cause various degrees of developmental delays, both physical and mental, for the growing baby. Although some variables do occur as a result of genetic conditions pertaining to the father, a great many are directly brought about from environmental toxins that the mother is exposed to.
Disease burden is the impact of a health problem as measured by financial cost, mortality, morbidity, or other indicators. It is often quantified in terms of quality-adjusted life years (QALYs) or disability-adjusted life years (DALYs). Both of these metrics quantify the number of years lost due to disability (YLDs), sometimes also known as years lost due to disease or years lived with disability/disease. One DALY can be thought of as one year of healthy life lost, and the overall disease burden can be thought of as a measure of the gap between current health status and the ideal health status. According to an article published in The Lancet in June 2015, low back pain and major depressive disorder were among the top ten causes of YLDs and were the cause of more health loss than diabetes, chronic obstructive pulmonary disease, and asthma combined. The study based on data from 188 countries, considered to be the largest and most detailed analysis to quantify levels, patterns, and trends in ill health and disability, concluded that "the proportion of disability-adjusted life years due to YLDs increased globally from 21.1% in 1990 to 31.2% in 2013." The environmental burden of disease is defined as the number of DALYs that can be attributed to environmental factors. Similarly, the work-related burden of disease is defined as the number of deaths and DALYs that can be attributed to occupational risk factors to human health. These measures allow for comparison of disease burdens, and have also been used to forecast the possible impacts of health interventions. By 2014, DALYs per head were "40% higher in low-income and middle-income regions."
Air pollution is the contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. It is also the contamination of indoor or outdoor surrounding either by chemical activities, physical or biological agents that alters the natural features of the atmosphere. There are many different types of air pollutants, such as gases, particulates, and biological molecules. Air pollution can cause diseases, allergies, and even death to humans; it can also cause harm to other living organisms such as animals and crops, and may damage the natural environment or built environment. Air pollution can be caused by both human activities and natural phenomena.
Ultrafine particles (UFPs) are particulate matter of nanoscale size (less than 0.1 μm or 100 nm in diameter). Regulations do not exist for this size class of ambient air pollution particles, which are far smaller than the regulated PM10 and PM2.5 particle classes and are believed to have several more aggressive health implications than those classes of larger particulates. In the EU UFP's in ambient air are empirically defined by a technical specification. The important detail is the definition of size, stated: "The lower and upper sizes considered within this document are 7 nm and a few micrometres, respectively". Although the most common referral to UFP is "less than 0.1μm", this is incorrect for ambient air in the EU.
Air pollution is the introduction of chemicals, particulate matter, or biological materials into the atmosphere, causing harm or discomfort to humans or other living organisms, or damaging ecosystems. Air pollution can cause health problems including, but not limited to, infections, behavioral changes, cancer, organ failure, and premature death. These health effects are not equally distributed across the U.S population; there are demographic disparities by race, ethnicity, socioeconomic status, and education. Air pollution can derive from natural sources, or anthropogenic sources. Anthropogenic air pollution has affected the United States since the beginning of the Industrial Revolution.
Air pollution is the release of pollutants into the air that are detrimental to human health and the Earth. In Canada, air pollution is regulated by standards set by the Canadian Council of Ministers of the Environment (CCME), an inter-governmental body of federal, provincial and territorial Ministers responsible for the environment. Air pollution from the United States and to lesser extent Canada; caused by metal smelting, coal-burning for utilities, and vehicle emissions has resulted in acid rain, has severely impacted Canadian waterways, forest growth, and agricultural productivity.
Particulates or atmospheric particulate matter are microscopic particles of solid or liquid matter suspended in the air. The term aerosol commonly refers to the particulate/air mixture, as opposed to the particulate matter alone. Sources of particulate matter can be natural or anthropogenic. They have impacts on climate and precipitation that adversely affect human health, in ways additional to direct inhalation.
In the United States about 10% of the population, 33 million people, live within 900 meters of a high traffic road High-traffic roads are commonly identified as being host to more than 50,000 vehicles per day, which is a source of toxic vehicle pollutants. Previous studies have found correlations between exposure to vehicle pollutants and certain diseases such as asthma, lung and heart disease, and cancer among others. Car pollutants include carbon monoxide, nitrogen oxides, particulate matter, and toxic air pollutants While these pollutants affect the general health of populations, they are known to also have specific adverse effects on expectant mothers and their fetuses. The purpose of this article is to outline how vehicular pollutants affect the health of expectant mothers and the adverse health effects these exposure have on the adult.
Douglas William Dockery is an American epidemiologist and the John L. Loeb and Frances Lehman Loeb Professor of Environmental Epidemiology at the Harvard School of Public Health (HSPH).
The World Health Organization guidelines were most recently updated in 2021. The guidelines offer guidance about these air pollutants: particulate matter (PM), ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2) and carbon monoxide (CO). The WHO first released the air quality guidelines in 1987, then updated them in 1997. The reports provide guidelines intending to give guidelines to reduce the health effects of air pollution.
Air quality in Utah is often some of the worst in the United States. Poor air quality in Utah is due to the mountainous topography which can cause pollutants to build up near the surface combined with the prevalence of emissions from gasoline- and diesel-powered vehicles, especially older models. Burning wood fuel for home heating can also contribute significantly to poor air quality. Homes heated with wood contribute about 3000 times the amount of pollution as homes heated with natural gas. About 50% of air pollution in Salt Lake County is from vehicles.
Anna Louise Hansell is a British physician who is Professor of Environmental Epidemiology and Director of the Centre for Environmental Health and Sustainability at the University of Leicester. During the COVID-19 pandemic, Hansell studied the relationship between pollution and COVID-19.
The Harvard "Six Cities" study was a major epidemiological study of over 8,000 adults in six American cities that helped to establish the connection between fine-particulate air pollution and reduced life expectancy. Widely acknowledged as a landmark piece of public health research, it was initiated by Benjamin G. Ferris, Jr at Harvard School of Public Health and carried out by Harvard's Douglas Dockery, C. Arden Pope of Brigham Young University, Ferris himself, Frank E. Speizer, and four other collaborators, and published in the New England Journal of Medicine in 1993. Following a lawsuit by The American Lung Association, the study, and its various follow-ups, led to a tightening of pollution standards by the US Environmental Protection Agency. This prompted an intense backlash from industry groups in the late 1990s, culminating in a Supreme Court case, in what Science magazine termed "the biggest environmental fight of the decade".
Particulate pollution is pollution of an environment that consists of particles suspended in some medium. There are three primary forms: atmospheric particulate matter, marine debris, and space debris. Some particles are released directly from a specific source, while others form in chemical reactions in the atmosphere. Particulate pollution can be derived from either natural sources or anthropogenic processes.
Frank Erwin Speizer is an American physician and epidemiologist, currently Professor of Environmental Health and Environmental Science at Harvard T.H. Chan School of Public Health, and Edward H. Kass Distinguished Professor of Medicine at Brigham and Women's Hospital, Harvard Medical School. He is best known for his work on two major epidemiological cohort studies: the Nurses' Health Study, which explored women's illnesses and health risk factors, and the Harvard Six Cities study, which definitively linked air pollution to higher death rates in urban areas.
Francine Laden is an American epidemiologist who is Professor of Environmental Epidemiology at the Harvard T.H. Chan School of Public Health. Her research has investigated the environmental epidemiology of chronic disease. She serves as co-director of the Harvard University and Boston University center for research on environmental and social stressors in housing across the life course. Laden has also served on the United States Environmental Protection Agency advisory board.
Lester Barnard Lave was an American economist who helped pioneer the field of environmental economics, notably the idea that environmental problems have quantifiable economic costs. In August 1970, over two decades before the Harvard Six Cities study definitively settled the issue, Lave and his graduate student Eugene P. Seskin published research suggesting that air pollution in American cities was causing higher death rates and attempted to calculate its economic cost. Lave went on to publish books and papers on many other environmental issues, including toxic chemicals, soil carbon, and electric cars, and studied methodological tools such as cost-benefit and risk analysis. At the time of his death, he was Harry B. and James H. Higgins Professor of Economics at the Tepper School of Business, professor of engineering and public policy, director of the Green Design Institute, and co-director of the Electricity Industry Center at Carnegie Mellon University.
