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PU 430 Unit 9 Chapters 7, 12, 13 Heat Waves Chapter Seven Heat Waves One of the most subtle yet most lethal disasters These produce greater mortality than hurricanes, tornadoes, & earthquakes combined Future predictions of heat wave occurrences & severity look harsh The human body maintains an internal temperature within a very narrow range When environmental conditions or physical activity generate more heat than the body can regulate, there is an increased risk for heat-related illnesses Dehydration is also a critical risk factor for heat illness The NWS has developed a Heat Index to reflect the apparent temperature when humidity is factored into the conditions Effects on the Human Body All deaths from heat waves are preventable Heat waves can be predicted & the measures needed to successfully manage their impact are well understood & inexpensive It is important that the community engage in preparedness activities specifically for a heat emergency Prevention This refers to the alteration of the environment resulting from urban development combined with the added heat generated by population density The combination of the following factors contributes to a rise in urban & suburban temperatures: ◦ Urban industrial & transportation activities ◦ The reduction in vegetation across urban areas reduces the shading of buildings & surfaces ◦ Dark colored roofs & pavements are less reflective & absorb more heat ◦ Taller structures block air movement & further reduce the rate at which these surfaces can cool Mitigation measures to reduce urban heat islands are simple & offer benefits far beyond the reduction in heat Urban Heat Island Mitigation The most important steps a community can take is to identify vulnerable populations in advance & determine the best methods to get information into their hands Many cities have poor heat emergency plans or none at all No specific standards exist that prescribe appropriate preparedness & response actions An effective plan will reduce the impact of a heat wave on the health of the affected population and must include: ◦ A phased approach that addresses the measures taken by each agency leading up to the summer season ◦ A clearly defined role of each local agency ◦ A standard warning system that must emphasize & target vulnerable populations Preseason Community Preparedness Activities Workplace Heat Stress Prevention OSHA mandates that employers must “furnish to each of his employees employment & a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm” If you work in a hot environment, you must be oriented before regular heat exposure, which should include: ◦ A screening process to identify & quantify risk factors ◦ A time must be established for acclimatization of the body to the hot environment through incremental exposures The basic steps needed for an effective response to a heat wave begin with community planning & personal preparedness Effective strategies should begin with the formation of a local or regional Heat Wave Task Force Building a heat wave resilient community includes measures that reduce the possibility of failure of critical infrastructures such as power grids Reducing the health impact of heat on vulnerable populations is best achieved through communicating basic personal preparedness measures & emphasizing actions taken to cool down Immediate Actions All the personal variables that may influence your risk & plan for the warm season need to be considered: ◦ Lighter colored clothes ◦ Loose-fitting, light weight clothing ◦ Plan activities that keep you in the shade or prepare to wear a hat & use sunscreen with a high SPF ◦ Simply slow down ◦ Avoid excessive exertion during peak temperatures of the day ◦ Avoid heavy meals Personal Actions The central focus of community heat wave preparedness is identifying & communicating with vulnerable populations Each public & private organization involved must clearly understand their function before the emergency & be prepared to quickly carry out their assigned roles The media can assist in reaching a large portion of vulnerable individuals Community Actions Heat Wildfires Chapter Thirteen Wildfires Wildfires have always been part of the ecosystem & are often natural occurrences started by lightning strikes They are also sometimes manmade through carelessness or intentional fire starting These fires thrive best in areas that have vegetation, winds, & periods of dry weather These fires can naturally occur & actually have long-term benefits for some ecosystems Human habitation near susceptible areas places populations at risk for major public health, economic, & environmental damage Wildfire smoke is a complex assortment of gases & particles The obvious risks are burns & heat injuries, but the most far-reaching & challenging health issue is smoke The smoke produced by wildfires can produce effects ranging from airway & eye irritation to death The primary short-term inhalational challenges are particles that irritate the airway & cause symptoms even among healthy exposed individuals, including coughing, wheezing, & difficulty breathing Other smoke components have toxicity potential as allergens, carcinogens, mutagens, & teratogens The majority of the exposed population will not experience long-term effects from wildfire smoke Effects on the Human Populations Preparing for wildfires begins with an assessment of local risk & history of wildfires in the region A long dry weather period can introduce the risk of wildfires to areas with little or no history A 30-foot safety zone around a home is recommended to reduce the wildfire risks to the structure The amount & type of vegetation in a zone known to have wildfire risks should be carefully considered Prevention If there is a reasonable chance that a wildfire will threaten human lives & property, evacuation orders are issued The following precautions should be taken: ◦ If you are trapped in a stranded vehicle, it is usually better to stay in the vehicle than to try & outrun the advancing fire on foot ◦ If you are trapped inside a home or other structure, it is best to remain inside long enough for the worst of the wildfire to pass by ◦ If you are outside when fires approach, the best action is to find the closest area with the least amount of vegetation or fuel to burn ◦ The minimum protection against wildfire smoke is a properly fitted N-95 respirator Immediate Actions It is important to check the roofs & attics of affected buildings for fires & embers For several hours after, there should be a “fire watch” with regular monitoring for signs of smoke & fire throughout nearby structures The primary residual hazard is the fire ash accumulation Response & Recovery Challenges Arizona 2011 Volcanoes Chapter Twelve Volcanoes Volcanoes are responsible for the formation of much of the Earth’s surface They are typically hills or mountains that surround a vent leading to reservoirs of molten rock below the Earth’s surface There are four primary types of volcanoes: ◦ ◦ ◦ ◦ Cinder Cone Composite Shield Lava Dome The Volcanic Explosivity Index (VEI) is a composite, semiquatitative estimate of a volcano’s eruptive power During a volcanic eruption, there are a variety of hazards produced: ◦ Gases and particles are rapidly ejected, reaching heights of up to 10–20 miles and can literally be carried around the planet ◦ Direct blasts and flows are projected laterally ◦ Large rocks and enormous volumes of materials can be hurled at a high rate of speed for many miles ◦ Clouds of hot particles and gases that spill down the slopes of a volcano (pyroclastic flows) may form ◦ Particles separate into layers of different charges generating lightening similar to what is seen during thunderstorms ◦ Downwind areas are covered with ash ◦ Lahars are often formed Volcanoes (continued) Direct hazards include rocks, ash, gases, and heat from an eruption Larger solid debris can cause ballistic injuries for miles Gases can cause respiratory damage Pyroclastic flows and lava flows can cause thermal injuries Carbon dioxide and debris from an eruption can cause asphyxiation Other hazards result from secondary events, including earthquakes, flooding, landslides, lightening, and even tsunamis Health Effects Preparedness measures for volcanoes begin with a home preparedness kit and an understanding of the risk for volcanic eruptions Unlike many other natural disaster threats that are focused tightly on a specific geographic region, volcanoes can reach hundreds of miles downwind and cause severe interruption in critical infrastructure Even if you are near a dormant volcano, you should have a plan and be prepared to evacuate quickly People should be encouraged to avoid active volcanoes If you are close enough to observe a volcanic eruption, you are in unnecessary danger Prevention Ideally, there should be an evacuation order given and everyone should evacuate from the area During evacuation, avoid areas downwind and avoid river valleys downstream from the volcano If you are outside, seek inside shelter immediately Avoid low-lying areas where mudflows are possible Remember to help neighbors that may need assistance Bring all animals and livestock under cover in closed shelters Put all machinery inside closed garages or barns Once indoors: ◦ Close all the windows, doors, fireplace dampers, etc. ◦ Close down your heating, ventilation, and air conditioning ◦ Place damp, rolled towels along base of the doors and anyplace else where a draft may introduce ash into the building Immediate Actions Local emergency management officials will provide detailed instructions to area residents If it is necessary to go outside, during or immediately after the ash fall, cover your mouth and nose to filter out the larger particles and protect your respiratory tract All exposed skin should be covered Goggles should be worn when clearing the roof of ash accumulation Outer clothing should be removed before entering the building to limit the transport of ash into the structure Response and Recovery Challenges Chile 2011 Case Study-Climate Change and Public Health (reference: Jonathan E. Fielding, MD, MPH, Public Health Director and Health Officer Los Angeles County Department of Public Health ) It is our job to protect the public’s health Fighting climate change is aligned with protecting and promoting health ◦ WHO estimates that in the year 2000, there were 150,000 excess deaths per year due to climate change ◦ Climate change is already affecting health around the world, and its impact on health will continue to grow ◦ Many of the proposed solutions for climate change are healthy for everyone We have the appropriate skills ◦ Public Health has the skills to effect behavior change, and those skills can help people adopt greener behaviors too ◦ Public Health has policy and advocacy skills that will help encourage organizational and societal changes Role of Public Health Extreme weather and disease Effects of rising sea level • Coastal areas will become vulnerable to storms and flooding • Loss of coastal wetlands and erosion of beaches • Saltwater contamination of drinking water • Potential damage to roads, highways, and other infrastructures near coastal areas Sea level rise Warmer temperatures can result in premature and rapid snowmelt in the Sierra snow pack, which alters the timing of run-off water supplies for ½ of CA’s surface water Severe flooding may Drought risk may be acutely elevated during the summer months occur during winter and spring, with slower water flow during summer seasons Example California Los Angeles projected to have an increase of 62% 88% in heat-related mortality by 2080 Health impacts likely to be seen 1 to 3 days after the onset of the heat waves Health effects of extreme and prolonged heat exposure include: heat cramps, heat exhaustion, heat stroke, heat syncope (fainting) Devastating heat waves seen elsewhere recently 5-day heat wave in Chicago in 1995: 700 excess deaths, most attributed to the heat August 2003 European heat wave: 35,000 excess deaths Health Impacts of Heat Waves Greater risk for people who do not have access to air conditioning May not be able to afford air conditioning For populations unaccustomed to heat waves, people may have air conditioning but chose not to use it, not realizing danger Two vulnerable populations during heat waves: Elderly: Population of senior citizens (> 60 years old) in Los Angeles County is expected to increase by 83% by the year 2020 Low SES: Over 16% of LA County residents under 100% FPL Heat Waves: Vulnerable Populations Increased temperature and increased carbon dioxide in atmosphere leads to Increase in formation of ground-level ozone (and smog) Increased allergen production (e.g. pollen) Longer seasons for allergen producing weeds Senior citizens, children, and people with respiratory and chronic diseases are most vulnerable to high levels of ozone and increased allergens Health effects of high levels of ozone exposure include: Reduced lung function Respiratory discomfort Exacerbation of chronic respiratory illnesses Public health already utilizes a multi-level prevention approach – analogous approach can be taken to respond to climate change Primary prevention = climate change mitigation Efforts to slow, stabilize, reverse climate change by reducing GHG emissions Efforts will occur in sectors other than PH, such as energy and transportation Secondary/tertiary prevention = climate change adaptation Efforts to prepare for, and minimize health burden of, climate change Similar to public health preparedness for other uncertainties (e.g. pandemic flu, bioterrorist attack), so likely that PH as sector will be involved in adaptation efforts Public Health Response Mitigation = reduce GHG emissions Reduce energy usage and Reduce, Reuse, Recycle 1. 2. As individuals, at home As organizations, at work Adaptation = prepare for impact of climate change Emergency preparedness 1. 2. As individuals/families As local health department Mitigation and adaptation = advocate for healthy policies 1. Support legislation that reduces GHG emissions 2. Support sustainable lifestyles & communities Actions We need to prepare now for the inevitable effects of climate change, such as heat waves and wildfires Good news: preparing for one type of emergency prepares us for all types of emergencies Preparation minimizes impact of disasters and fear/anxiety We need to prepare ourselves as individuals and as health agencies Preparation