1、10.1CHAPTER 10INDOOR ENVIRONMENTAL HEALTHBACKGROUND. 10.1Health Sciences Relevant to Indoor Environment . 10.3Hazard Recognition, Analysis, and Control 10.4AIRBORNE CONTAMINANTS 10.4Particles . 10.5Gaseous Contaminants 10.9PHYSICAL AGENTS 10.16Thermal Environment. 10.16Electrical Hazards . 10.19Mech
2、anical Energies 10.19Electromagnetic Radiation. 10.21Ergonomics 10.23Outdoor Air Ventilation and Health 10.23NDOOR environmental health comprises those aspects of humanI health and disease that are determined by factors in the indoorenvironment. It also refers to the theory and practice of assessing
3、 andcontrolling factors in the indoor environment that can potentiallyaffect health. The practice of indoor environmental health requiresconsideration of chemical, biological, physical and ergonomic haz-ards, and has the goal of increasing healthy indoor environments.Diseases are caused by genetics
4、and exposures biological (biotic)and/or chemical or physical (abiotic). Despite a huge investment inDNA research in recent decades, few diseases can be solely explainedby our genes. An interaction between genes and environmental expo-sures is needed, and understanding indoor environmental exposuresi
5、s essential in this respect. Over a 70-year lifespan in a developedregion, indoor air (in homes, schools, day cares, offices, shops, etc.)constitutes around 65% of the total lifetime exposure (in mass),whereas outdoor air, air during transportation, food, and liquid makesup the rest. For more vulner
6、able populations, such as newborns, theelderly, and the homebound ill, indoor air in homes makes up around80% of the exposure.It is essential for engineers and others involved in building designand operation to understand the fundamentals of indoor environ-mental health because the design, operation
7、, and maintenance ofbuildings and their HVAC systems significantly affect the health ofbuilding occupants. In many cases, buildings and systems can bedesigned and operated to reduce the exposure of occupants to poten-tial hazards. Unfortunately, neglecting to consider indoor environ-mental health ca
8、n lead to conditions that create or worsen thosehazards and increased associated exposure.This chapter provides general background information and intro-duces important concepts of hazard recognition, analysis, and con-trol. It also presents information on specific hazards, and describessources of e
9、xposure to each hazard, potential health effects, relevantexposure standards and guidelines, and methods to control expo-sure.This chapter also includes a brief introduction to the very broadand dynamic field of indoor environmental health. Thus, descriptionsof potential hazards (and especially thei
10、r controls) presented do notconstitute a comprehensive, state-of-the-art review. Additional detailis available on many important topics in other ASHRAE Handbookchapters, including Chapter 9, Thermal Comfort, of this volumeChapter 11, Air Contaminants, of this volumeChapter 12, Odors, of this volumeC
11、hapter 16, Ventilation and Infiltration, of this volumeChapter 29, Air Cleaners for Particulate Contaminants, of the2016 ASHRAE HandbookHVAC Systems and EquipmentChapter 31, Ventilation of the Industrial Environment, of the 2015ASHRAE HandbookHVAC ApplicationsChapter 46, Air Cleaners for Gaseous Con
12、taminants, of the 2015ASHRAE HandbookHVAC ApplicationsOther important sources of information from ASHRAE includethe building ventilation and related requirements in Standards 62.1and 62.2, as well as Standard 170 for health care occupancies andthe Indoor Air Quality Guide (ASHRAE 2009). Additional d
13、etailsare available from governmental and private sources, including theU.S. Department of Health and Human Services Centers for Dis-ease Control and Prevention, U.S. Environmental ProtectionAgency, Occupational Safety and Health Administration, AmericanConference of Governmental Industrial Hygienis
14、ts, National Insti-tute for Occupational Safety and Health, parallel institutions in othercountries, and the World Health Organization.1. BACKGROUNDEvaluation of exposure incidents and laboratory studies with hu-mans and animals have generated reasonable consensus on safe andunsafe workplace exposur
15、es for about 1000 chemicals and particles.Consequently, many countries regulate exposures of workers to theseagents. However, chemical and particle concentrations that meet oc-cupational health criteria usually exceed levels acceptable to occu-pants in nonindustrial spaces such as offices, schools,
16、and residences,where exposure times often last longer and exposures may involvemixtures of many contaminants and where those exposed comprise aless robust population (e.g., infants, the elderly, the infirm) (NAS1981).The generally accepted broad definition of health is that in theconstitution of the
17、 World Health Organization (WHO): “Health is astate of complete physical, mental, and social well-being and notmerely the absence of disease or infirmity.”Another definition of health, more narrowly focused on air pol-lution, presented by the American Thoracic Society (ATS 1999)takes into account br
18、oader, societal decision-making processes indefining what constitutes an adverse health effect of air pollution.Key points of the ATS definition of adverse effects includeBiomarkers, or biological indicators (e.g., in blood, exhaled air,sputum) of environmental effects. Because few markers have yetb
19、een sufficiently validated for use in defining thresholds, not allchanges in biomarkers related to air pollution should be consideredadverse effects.Quality of life. Adverse effects of air pollution can range fromwatering, stinging eyes to cardiopulmonary symptoms, and evenpsychiatric conditions.Phy
20、siological impact. Physical effects of pollution can be transi-tory or permanent, and appear alone or accompanied by othersymptoms. The ATS minimum requirement for considering pollu-tion to have an adverse effect is reversible damage accompaniedThe preparation of this chapter is assigned to the Envi
21、ronmental HealthCommittee.10.2 2017 ASHRAE HandbookFundamentals by other symptoms (reversible damage alone is not sufficient).Also, effects such as developmental damage to lungs, or exacer-bation of age-related decay in function, must be considered.Symptoms. Not all increased occurrences of symptoms
22、 are con-sidered adverse effects of air pollution: only those diminishing anindividuals quality of life or changing a patients clinical statusshould be considered adverse.Clinical outcomes. Detectable effects of air pollution on clinicaltests should be considered adverse.Mortality. Any increase in m
23、ortality should be judged adverse.Population health versus individual risk. Any increase in therisk of an exposed population should be considered adverse, evenif there is no immediate, outright illness.Definitions of comfort vary. Comfort encompasses perception ofthe environment (e.g., hot/cold, hum
24、id/dry, noisy/quiet, bright/dark)and a value rating of affective implications (e.g., too hot, too cold).Rohles et al. (1989) noted that acceptability may represent a moreuseful concept of evaluating occupant response, because it allowsprogression toward a concrete goal. Acceptability is the foundati
25、onof a number of standards covering thermal comfort and acoustics, aswell as odor comfort. Nevertheless, acceptability varies between cli-matic regions and cultures, and may change over time as expecta-tions change.Concern about the health effects associated with indoor air datesback several hundred
26、 years, and has increased significantly in recentdecades. During the 1970s and 1980s, this attention was mainly aresult of concerns about radon and lung cancer, and about increasedreporting by building occupants of complaints about poor healthassociated with exposure to indoor air or sick building s
27、yndrome(SBS). More recently, interest has largely focused on asthma,allergies, and airway infections.SBS encompasses a number of adverse health symptoms relatedto occupancy in a “sick” building or room, including mucosal irrita-tion, fatigue, headache, and, occasionally, lower respiratory symp-toms,
28、 and nausea. Large field studies (EPA 2012; Skov and Valbjorn1987; Sundell et al. 1994) have shed light on the causes. Widespreadoccurrence of these symptoms prompted the World Health Orga-nization to classify SBS symptoms (WHO 1983):General symptoms, such as headache, tiredness, nauseaMucous membra
29、ne symptoms in the nose, eyes, or throat, includ-ing coughing, sensations of drynessSkin symptoms: redness, itching, on upper body partsSick building syndrome is characterized by an absence of routinephysical signs and clinical laboratory abnormalities with regard tosensory irritation and neurotoxic
30、 symptoms, while skin symptomsoften can be objectively verified. Some investigations have sought tocorrelate SBS symptoms with reduced neurological and physiologi-cal performance. In controlled studies, SBS symptoms can reduceperformance in susceptible individuals (Mlhave et al. 1986).Building-relat
31、ed illnesses (BRIs) have similar symptoms, butinclude physical signs and abnormalities that can be more easilyclinically identified (e.g., hypersensitivity illnesses, including hy-persensitivity pneumonitis, humidifier fever, asthma, and allergicrhinitis).Some illnesses associated with exposure in i
32、ndoor environmentsare listed in Table 1.Table 1 Selected Illnesses Related to Exposure in BuildingsIllness Physical Examination Laboratory Testing Linkage Causes/ExposuresAllergic rhinitis Stuffy/runny nose, postnasal drip, pale or erythematous mucosaAnterior and posterior rhinomanome-try, acoustic
33、rhinometry, nasal lavage, biopsy, rhinoscopy, immunoassay (IgE) or skin prick testingImmunologic skin prick or immunoassay (IgE) or in vitro testingPollen and dust mites are com-mon examplesAsthma Coughing, wheezing, episodic dyspnea, wheezing on examination, chest tightness, temporal pattern at wor
34、kSpirometry peak expiratory flow diary, methacholine challenge, exhaled NOImmunology testing: skin prick or immunoassay (IgE); phys-iology testing*Pet dander, mold, environmental tobacco smoke, and dust mites are common examplesOrganic dust toxic syndromeCough, dyspnea, chest tight-ness, feverishnes
35、sDLCO, TLC Temporal pattern related to workGram-negative bacteria or endotoxinHypersensitivity pneumonitisCough, dyspnea, myalgia, weakness, rales, clubbing, feverishnessDLCO, FVC, TLC, CXR, lung biopsy Immunology testing: IgG anti-body to agents present, chal-lenge testing, physiology testing (in a
36、cute forms): spirometry, DLCOCausative agents include thermophilic actinomycetes; molds; mixed amoebae, fungi, and bacteria; avian proteins; certain metals and chemicalsContact dermatitis Dry skin, itching, scaling skin Scaling, rash, eczema, biopsy Patch testing; allergy testingUrticaria (hives) Mu
37、ltiple swollen raised itchy areas of skinInspection, biopsy Provocation testing Skin irritation, foods, heat/cold, direct pressure, sunlight, drugs Eye irritation Eye itching, irritation, drynessTear-film break-up time, conjunctival staining (fluorescein)Temporal pattern VOCs and particulate matter
38、are common examplesNasal irritation Stuffy, congested nose, rhinitisAcoustic rhinometry, posterior and anterior rhinomanometry, nasal lavage, nasal biopsyTemporal pattern VOCs and particulate matter are common examplesCentral nervous system symptomsHeadache, fatigue, irritability, difficulty concent
39、ratingNeuropsychological testing Temporal pattern (epidemiol-ogy)Chemical compounds, noise, lighting, work stress, and carbon monoxide are common examplesLegionnaires dis-ease, Aspergillosis, Pseudomonas infectionPneumonia, high fever, organ dysfunctionEnvironmental surveillance (water sys-tem monit
40、oring), Legionella pneu-mophila identification from patientOrganism isolated from patient and source; immunology testingLegionella (and other microorganism)-contaminated aerosols from water sourcesPontiac fever Non-pneumonic flulike illnessEnvironmental surveillance (water sys-tem monitoring)Range o
41、f microorganisms, chemicals*(1) 10% decrement in FEV1across workday,(2) peak flow changes suggestive of work relatedness(3) methacholine reactivity resolving after six weeks away from exposureDLCO = single breath carbon monoxide diffusing capac-ityFVC = forced vital capacityTLC = total lung capacity
42、CXR = chest X-rayIgE = immunoassayIgG = class G immunoglobulinsFEV1= forced expiratory volume in the first secondIndoor Environmental Health 10.31.1 HEALTH SCIENCES RELEVANT TO INDOOR ENVIRONMENTThe study of health effects in indoor environments involves anumber of scientific disciplines. A few are
43、briefly described here tofurther the engineers understanding of which health sciences maybe applicable to a given environmental health problem.Epidemiology and BiostatisticsEpidemiology studies the causes, distribution, and control of dis-ease in a population. It represents the application of quanti
44、tativemethods to evaluate health-related events and effects. Epidemiologyis traditionally subdivided into observational and analytical compo-nents; the focus may be descriptive, or may attempt to identify causalrelationships. Some classical criteria for determining causal relation-ships in epidemiol
45、ogy are consistency, temporality, plausibility,specificity, strength of association, and dose/response (Hill 1965).Observational epidemiology studies are generally performedwith a defined group of interest because of a specific exposure orrisk factor. A control group is selected on the basis of simi
46、lar crite-ria, but without the exposure or risk factor present. A prospectivestudy (cohort study) consists of observations of a specific groupover a long time.Examples of epidemiological investigations are cross-sectional,experimental, and case-control studies. Observations conducted atone point in
47、time are considered cross-sectional studies. In experi-mental studies, individuals are selectively exposed to a specificagent or condition. These studies are performed with the consent ofthe participants unless the condition is part of the usual workingcondition and it is known to be harmless. Contr
48、ol groups must beobserved in parallel. Case-control studies are conducted by identi-fying individuals with the condition of interest and comparing fac-tors of interest in individuals without that condition.Industrial, Occupational, and Environmental Medicine or HygieneIndustrial or occupational hygi
49、ene is about anticipating, recog-nizing, evaluating, controlling, and preventing conditions that maylead to illness or injury, or affect the well-being of workers, consum-ers, and/or communities. Important aspects include identifying haz-ardous exposures and physical stressors, determining methods forcollecting and analyzing contaminant samples, evaluating measure-ment results, and developing suitable control measures. Occupa-tional hygienists work closely with toxicologists for understandingchemical hazards, physicists for physical hazards (e.g., ionizingradiation), and physi
