Air Pollution - Lecture 7 2024 PDF

Air Pollution Part 1 ENH524-Pollution and Waste Management School of Occupational and Public Health Toronto Metropolitan University  Air Pollution A mix of particles and gases that can reach harmful concentrations both outside and indoors Differs from ot...

Air Pollution Part 1 ENH524-Pollution and Waste Management School of Occupational and Public Health Toronto Metropolitan University  Air Pollution A mix of particles and gases that can reach harmful concentrations both outside and indoors Differs from other environmental pollution, in that exposure is unavoidable and affects entire population  Air Pollution Air pollutants are gases or particles in the atmosphere which have been linked to harmful human health or environmental effects – Can be directly emitted (primary pollutants) or formed in the atmosphere (secondary pollutants)  Air Pollution Criteria Air Contaminants (CAC): A set of air pollutants that cause smog, acid rain, and other health hazards. Mainly products of fossil fuel combustion. Particulate matter (PM), sulphur dioxide (SO2), nitrogen oxides, volatile organic compounds (VOCs), carbon monoxide (CO), ozone (O3), and lead  Burden of Illness Globally, 3.7 million deaths occur each year due to outdoor (ambient) air pollution – 8800 deaths/year in Canada from PM2.5, 680 from ozone The most widespread environmental carcinogen – In 2013, International Agency for Research on Cancer (IARC) classified outdoor air pollution and particulate matter as carcinogenic to humans (Group 1), especially affecting the lungs Numerous adverse health effects: – Asthma and other respiratory illnesses – Chronic obstructive pulmonary disease – Cardiovascular disease – Lung cancer – Endocrine system effects – Neurological effects – Diabetes, allergies, premature death Health Impacts of Air Pollution Source: European Environment Agency, 2013 Environmental Burden of Cancer in Ontario Estimates how many new cancer cases, diagnosed each year in Ontario, are a result of exposure to cancer-causing agents that exist in our environment. Sources of environmental carcinogens are air, food, drinking water, dust and radiation. https://www.publichealthontario.ca/- /media/documents/environmental-burden-cancer- on.pdf?la=en Environmental Burden of Cancer in Ontario Environmental Burden of Cancer: Estimates the annual number of cancer cases from 23 environmental carcinogens that Ontarians are exposed to by being in the sun, breathing indoor and outdoor air, eating food, drinking water and ingesting indoor dust. Environmental Burden of Cancer in Ontario There are between 3,540 and 6,510 new cancer cases each year in Ontario from exposure to these 23 carcinogens. Three carcinogens are associated with over 90 per cent of the environmental burden of cancer in Ontario: Solar ultraviolet radiation (2,090 to 2,990 cancer cases per year) Radon, a naturally occurring gas that can build up in lower levels of buildings (1,080 to 1,550 cancer cases per year) Fine particulate matter, an air pollutant that arises from combustion sources (290 to 900 cancer cases per year) PHO Infographic https://www.publichealthontario.ca/- /media/documents/environmental-burden-cancer- on-infog.pdf?la=en  Particulate Matter (PM) Mixture of solid and liquid particles suspended in the air – Can be primary (directly emitted) or secondary (formed from reactions with other pollutants in atmosphere) – In Canada, open sources (e.g. unpaved roads, construction) is most common source – In Ontario, an important source is wood-burning stoves PM categorized by size (aerodynamic diameter) – Size is related to its source, how it transports, and where it is deposited in the environment and respiratory system – PM10 = particles with aerodynamic diameter ≤10 µm – PM2.5 (fine PM) = particles with aerodynamic diameter ≤2.5 µm – Total PM = particles with aerodynamic diameter ≤100 µm Particulate Matter (PM)  Respiratory System Source: Frumkin et al., 2016  Particulate Matter (PM) Associated with numerous health effects: – Cardiovascular and respiratory mortality and morbidity – Growing evidence for adverse birth outcomes and childhood respiratory disease – Possible links with neurodevelopment, cognitive function, diabetes – Recent longitudinal study in Canada found increased risk of non- accidental death due to circulatory and respiratory disease from increasing PM2.5 exposures, even at low levels (6.3 μg/m3) Also linked to visual impairment, environmental damage, and aesthetic damage https://www.youtube.com/watch?v=wl3BkTE4TEc Particulate Matter Trends (1990-2017)  Sulphur Dioxide (SO2) Colourless, water-soluble gas with a sharp odour – Produced from the combustion of sulfur-containing fuels and materials (e.g. coal, metal ores) Atmospheric SO2 can be converted to sulfuric acid and contributes to formation of PM – Sulfuric acid is the main component of acid rain, which harms vegetation, buildings, and wildlife 1990 Annual Wet Sulfate Deposition 2000 Annual Wet Sulfate Deposition 2010 Annual Wet Sulfate Deposition  Sulphur Dioxide (SO2) Most inhaled SO2 is absorbed by the mucous membranes of the upper airways with little reaching the lung – However, can penetrate deeper into lungs with increased ventilation and breathing (e.g. during exercise) Health effects include: – Reduced lung function, bronchoconstriction (airway resistance), respiratory symptoms, hospitalization and death from cardiovascular and respiratory causes, eye irritation, adverse birth outcomes – Particularly at-risk populations include children, the elderly, and people with asthma Sulphur Dioxide emissions decreased by 69% between 1990 and 2017 (Environment Canada, 2019) Sulphur Dioxide Trends  In 1980s, not uncommon to record pH of 4.0 in Ontario rain  Nitrogen Oxides (NOx) Category of highly-reactive gases containing nitrogen and oxygen (i.e. nitrogen dioxide, NO2, and nitrogen oxide, NO) – Produced through combustion processes (heating, power generation, and engines in vehicles and ships); source is primarily transportation- related in Ontario (70%) Are precursors to ground-level ozone and PM, and also contribute to acid rain Health impacts include: – Reduced lung function; irritation of the eyes, nose, and throat; respiratory illness and death due to short- and long-term exposure; sensitivity increases for people with asthma and bronchitis From 1990 to 2017, national NOx emissions decreased by 26% (Environment Canada, 2019). NOx levels across the City of Toronto, 2006 Source: Toronto Public Health, 2014 Nitrogen Oxides Trends (1990-2017)  Volatile Organic Compounds (VOCs) Category of organic chemicals with a high vapor pressure, which readily evaporate at normal temperature and pressure – Originate from natural sources, industry, and transportation – In urban areas, anthropogenic sources are the main contributor Combine with nitrogen oxides to form ground-level ozone, and contribute to formation of secondary PM  VOCs Many individual VOCs also have direct toxic effects on humans, including: – Irritation of the respiratory tract, headaches, cancer, and neurotoxicity Between 1990 and 2017, VOC emissions decreased by 40% (Environment Canada, 2019). VOCs Trends (1990-2017) UK VOC trends  Carbon Monoxide (CO) Colorless, odorless, tasteless and poisonous gas – Results from incomplete combustion of fossil fuels Outdoor exposure is highest: – Near heavily trafficked city streets – During temperature inversions (cold weather) Once inhaled, disrupts oxygen transport in body – Enters bloodstream via lungs and forms carboxyhemoglobin, which inhibits blood's capacity to carry oxygen to organs and tissues Introduction and widespread use of catalytic converters in vehicles have reduced outdoor emissions Ontario AAQC for CO – 36.3 mg/m3 (30 ppm) 1-hour; 15.7 mg/m3 (13 ppm) 8-hour mean  Tropospheric Ozone (O3) In the stratosphere, ozone forms the naturally-occurring ozone layer that protects us from ultraviolet radiation – In the troposphere, “ground-level” ozone is formed through complex chemical reactions with VOCs and NOx in the presence of sunlight  Tropospheric Ozone (O3) Contributes to development of photochemical smog Excessive tropospheric ozone can cause: – Breathing problems, asthma, reduced lung function, lung diseases, respiratory and cardiorespiratory mortality – May affect cognitive development and reproductive health, including preterm birth – Children, people with asthma, those with heart and lung problems, and people who are active outdoors are at higher risk Negatively affects vegetation, crop production, and synthetic materials Air Quality Guidelines for ozone – Ontario = 165 μg/m3 (80 ppb) 1-hr mean – Canada (2015) = 63 μg/m3 8-hr mean  Smog Refers to a noxious mixture of gases and particles that often appears as a haze in the air – Primary pollutants are ground-level ozone and PM Linked to numerous adverse effects on health and the environment (depending on levels and types of pollutants in the air) Smog levels are higher in summer due the presence of sunlight and warmer temperatures – Winter smog can also occur due to PM Transboundary Contributions Urban Heat Island Image credit: NASA/JPL-Caltech Urban Heat Island Effect  Urban Heat Island Effect Urban heat islands refer to increased surface and air temperatures in urban vs. rural areas Can affect air quality by: – Increasing the rate of ground-level ozone formation – Increasing energy demand in the summer Can be controlled through: – Cool pavements – Cool roofs – Green roofs – Urban forestry  Urban Heat Island Effect Video: White Roads LA https://www.youtube.com/watch?v=wPJCTOQGU04 NASA: https://www.youtube.com/watch?v=lnBO4vX82Fs  Lead Sources of lead emissions vary from one area to another. Major sources of lead in the air: Ore and metals processing and piston-engine aircraft operating on leaded aviation fuel Waste incinerators, utilities, and lead-acid battery manufacturers. The highest air concentrations of lead are usually found near lead smelters  Lead In Canada, lead emissions decreased by 86% from 1990 to 2017. This decreasing trend is partly attributable to the closure of outdated smelters and partly to the implementation, since 2006, of regulated pollution prevention plans (Environment Canada, 2019). Lead National Trends  Lead & Health Depending on the level of exposure, lead can adversely affect the nervous system, kidney function, immune system, reproductive and developmental systems and the cardiovascular system. Lead exposure also affects the oxygen carrying capacity of the blood.  Case Study-Flint Water Crisis-2015 Flint is a city in Michigan with a population of about 100,000 In 2011, with Flint facing a $15 million debt, a state of financial emergency was declared and an Emergency Manager appointed to manage the city In an attempt to reduce drinking water costs in the face of rising prices from the water supply provided by Detroit; a new water supply from Lake Huron, the Karegnondi Water Authority (KWA) was found (projected to save Flint around $2 million a year) https://cen.acs.org/articles/94/i7/Lead-Ended-Flints-Tap-Water.html  Flint Water Crisis-2015 This prompted Detroit to terminate its contract to supply water to Flint with 12 months’ notice, leaving a gap of about two years until the KWA supply could put in service To meet the interim demand, Flint chose to use the water supply from Flint River, which went live in April 2014 Immediately after the changeover, residents complained about the taste, colour and odour of the water In August 2014, E. Coli bacteria were detected and the city issued a boil water notice. Then THM levels exceeded safe limits and the Michigan Department of Environmental Quality (DEQ) issued a violation notice  Flint Water Crisis-2015 In October 2014, the GM plant in Flint stopped using water from the Flint River supply because it was corroding motor parts It was known that the raw water was corrosive and that the water supply infrastructure included aging cast-iron pipes and solder that contain lead The records of the pipes’ location, age and condition were not in digital platform but instead were recorded on 4500 cards, some dating back a century. Corrosive water can leach lead toxins from these old pipes. Lead exposure can cause long-term physical, cognitive and nervous system damage Flint City, Michigan DEQ, and EPA had been locked in a debate over the need for corrosion control treatment, and compliance with the regulations  Flint Water Crisis-2015 Lead levels far exceeding acceptable standards were first detected in January 2015, and follow-up testing showed levels of 13,200 ppb, although the federal safe level is 15 Authorities were slow to act. The option to implement corrosion control treatment to minimize leaching was not put in place It was not until 18 months later, in September 2015, when Virginia Tech published report findings that Flint water was very corrosive and causing lead contamination in homes, and a concerned doctor released a study, confirming that the percentage of Flint children with elevated blood-lead levels had doubled since the implementation of the Flint River water supply In October 2016 Flint was reconnected to the Detroit water system * Courtesy of “Continuing Professional Development” Retrieved from https://continuingprofessionaldevelopment.org/  Flint Water Crisis results Between 6,000 and 12,000 children have been exposed to drinking water with high levels of lead and they may experience a range of serious health problems The water change is also a possible cause of an outbreak of Legionnaire’s disease in the county that has killed 10 people and affected another 77 More than a dozen state employees were criminally charged for their roles in the water crisis  It’s not just Flint… https://www.ctvnews.ca/health/worried-about- lead-in-your-water-here-are-some-steps-you-can- take-1.4670883  Lead Testing Toronto https://www.toronto.ca/services-payments/water-environment/tap- water-in-toronto/lead-drinking-water/lead-testing-for-residents/