As a third generation entrepreneur, Shinji strives to create a brand that is unique to him. He said that such goal is a norm in the Japanese big farming business, which contrasts with the quantity over quality emphasis of the Western–i.e., U.S. and Denmark—farmers. In the United States, people spend about 65% of their time indoors at home . Given that we spend so much time indoors, we should be concerned about indoor air quality because the indoor air quality of the space that we inhabit can have an impact on our health . Unhealthy indoor air quality has been linked to health conditions such as allergies, respiratory symptoms, and cancers . A top-down approach that focuses on governmental regulation is the current way of dealing with indoor air quality issues. Governmental regulation has focused on reducing the presence of pollutants in building materials and the installation of a ventilation system in buildings . There is also discussion about possible regulations that could be introduced to restrict the emissions of pollutants, banning the presence of certain pollutants, and introducing a minimum ventilation rate for indoor buildings . Occupants’ behaviors and the impact that they can play on indoor air quality are often relegated to the sideline. However, occupant’s behavior can mitigate indoor and/or outdoor characteristics, as they can worsen indoor air quality. An example of a behavior that can mitigate indoor air quality is when a home occupant affected by wildfire turns on the air purifier to improve indoor air quality . Behavior that can worsen indoor air quality is when a home occupant uses a cleaning product that contains chemicals that can react with ozone present in the home to form secondary pollutants. These two examples highlight the role that behavior can play in affecting indoor air quality.
Therefore,hydroponic racks the goal of this study is to understand the behaviors that could mitigate or worsen indoor air quality through its interaction with the indoor and outdoor characteristics of the home environment. Understanding the home occupant’s behavior might be the first step in implementing successful interventions to solve the indoor air quality issue. Implementing an effective intervention entails identifying the sources that result in unhealthy indoor air quality, quantifying the contribution of those sources, and the solutions to mitigate the sources of pollution. Indoor air quality can be affected by indoor sources, outdoor sources, and human behavior . Indoor sources include building materials and type of ventilation system , outdoor sources include traffic emission, location near a farm, and/or factory , and human behavior includes cooking, usage of a space heater, smoking, and the burning of a candle and incense can contribute to unhealthy indoor air quality . The approaches that various studies have taken to quantify the contribution of indoor sources, outdoor sources, and human behavior include 1) identifying the pollutants present in the home as a result of those sources, and 2) calculating the incidence of health symptoms and issues as a result of exposure to those sources. The studies that examined the pollutants present in the house focused on understanding the influence of outdoor sources on the pollutants that were found indoor . Those studies also investigated the effect of activities such as cooking and cleaning on particle concentration and mass . The studies that investigated the second approach examined the probability of developing health issues such as asthma and allergies following exposure to indoor sources such as latex wall paint, outdoor sources such as heavy traffic, or behavior such as vacuuming . Both approaches provide useful insights into the pollutants and sources that affect indoor air quality and the resulting health outcomes. However, there are shortcomings in both approaches. While it is helpful to know the influence of outdoor sources and behaviors on pollutants that are generated in the home, there could be other unmeasured pollutants that can affect the indoor air quality as well.
Similarly, it is useful to know the probability of developing health issues following exposure to various indoor, outdoor, or behavioral characteristics. However, a home occupant can be exposed to a multitude of indoor, outdoor, or behavioral sources on a given day which the current studies did not account for, such as exposure to traffic pollutants, vacuuming of the house, and the age of the home. The result of being exposed to various indoor, outdoor, and behavioral sources could result in home occupants having elevated exposure to pollutants thus worsening their health, or it might result in a reduction in health symptoms if some of the behaviors serve as mitigators. While there have been studies that examined the impact of behaviors such as using a range hood while cooking on the concentration of indoor air pollutants , and vacuuming to reduce dust particles , those studies did not investigate the impact of those behaviors on health. To better understand, the effect of indoor air quality on health outcomes, it is necessary to examine the effect of exposure to multiple sources of pollutants, i.e. indoor sources, outdoor sources, and behavioral sources. In addition to understanding the effect of exposure to multiple sources of pollutants and their contribution to health outcomes, it is also important to understand the behaviors that can mitigate the health effect of being exposed to pollutants. Therefore, the goal of this study is to understand the contribution of multiple sources of pollutants on health and the type of behaviors that can mitigate the effect that unhealthy indoor air quality has on health. The first aim will be to understand 1) the effect of exposure to multiple sources of negative indoor characteristics and outdoor characteristics, and 2) how behaviors can interact with those characteristics to ameliorate negative indoor air quality and improve health outcomes.
Specifically, the research questions that this study will address are 1) What are the contributions of indoor sources, outdoor sources, and behavioral sources of pollutants to health symptoms? and 2) What are the behaviors that can moderate the effect of living in a home with a poor indoor condition and negative outdoor environment ?The possible causes of hazards of indoor source include the building structure , the building mechanical system , the furnishings in the home , and human occupants , 2005). Demographics such as the number of occupants, type of home can also present a challenge to indoor air quality. Older homes, apartments, and homes with more occupants reported worse indoor air quality . Researchers in Sweden found that there was a higher level of volatile organic compounds in older homes, with VOCs origin related to indoor sources . Older homes are also more susceptible to the penetration of outdoor ultra fine particles because they are generally less air-tight. It might also be hazardous to live in a multifamily home as the total bacteria count in the home increases with the number of occupants . Areas with a greater percentage of low-income, minorities, renter-occupied, and lower education attainment households are also likely to be in proximity to hazardous sites . Some parts of a building structure, such as a crawlspace, basement, garage, and cladding, might pose a problem for indoor air quality. A crawlspace can be problematic because the surfaces of the crawlspace are conducive to mold growth, especially in the summer.Similarly, homes with a basement might suffer from unhealthy indoor air quality . The correlation between concentrations of VOCs in the living area and basement was found to be moderate across homes in the U.S. . The relationship between the presence of VOCs in the living area and the basement suggests that air quality in the living area may be affected if the basement is used as a chemical storage facility . Furthermore,indoor garden table there is evidence of elevated levels of microbial VOCs in the basement of some homes despite no report of mold growth in the living area . An attached garage also presents a problem to indoor air quality because homes with an attached garage can report elevated levels of VOCs in the indoor living area . The cladding is an aspect of building design that also plays a role in indoor air quality. In general, cladding that is of organic material such as wood is more susceptible to mold, though the extent of its susceptibility depends on the chemical composition and finishing .
Other than building structure, mechanical systems also play a role in indoor air quality . The type of heating system that homeowners have can make a difference in indoor air quality. Using a wood stove fireplace for heating can increase the particulate matter and benzopyrene to levels that are above the safe limit . While the heating system is not a major contributor to UFPs, it still produces UFPs and some heating systems produce more UFPs than others. Specifically, an electric baseboard heater and a wood-stove heater result in a greater concentration of UFPs than a forced-air natural gas furnace . While the use of a central heating system can enhance thermal comfort for the occupants, the overall increase in indoor temperature, can result in reduced air exchange rate making the home a conducive environment for the proliferation of dust mite and mold . Apart from building structures and mechanical systems, home furnishings also contribute to indoor air quality. Homes with carpets are reported to have more dust particles than homes without floor covering, carpeted homes also reported higher rates of dust particles resuspension. The health problems associated with carpeting include respiratory problems and symptoms of sick building syndrome . Furnishings such as carpet, wood furniture, and wall covering are also sources of VOCs . Exposure to VOC is linked to eye, nose, and throat discomfort, coughing, and headache .There are various negative environmental hazards that home occupants can be exposed to depending on the location of their homes. Home occupants who live near a restaurant can be subjected to elevated levels of polycyclic aromatic hydrocarbon . It is also not ideal to live downwind of an airport as the concentration of carbon monoxide , carbon dioxide , nitrogen oxide , nitrogen dioxide , black carbon, and PAH are much higher than in homes that are not downwind of the airport . Homes that are near farms might also find chemical components of pesticides in their house dust . Tetrachloroethylene is a chemical that is emitted from dry cleaners. Homes that are situated close to dry cleaners are at risk of heightened exposure to this compound . Living near a highway or major traffic can affect the indoor air quality adversely as well because occupants might be exposed to pollutants such as PM10, PM2.5, VOCs, and NO2 and such exposure can have a debilitating effect on cardiovascular and respiratory health . A residence that is close to one or more industrial sites is a concern too as some studies have found an increased cancer risk among those home occupants . Finally, a high-humidity climate can encourage mold growth but it can also hinder the resuspension of dust particles . This study investigated the relationship between indoor, outdoor, and behavioral characteristics and used the number of active health symptoms experienced as a dependent variable, which were collected through a secondary data analysis of home occupants. The secondary data were analyzed with a negative binomial regression model because the dependent variable is a count outcome with over dispersion. There were five models in the stepwise negative binomial regression model. Variables used in this study comes from the administration of two surveys. The first survey was administered by the team at Hayward Score, a California company that has developed a scoring system to evaluate the health impacts of homes among volunteer participants. The volunteer participants survey includes a series of questions on home conditions , outdoor conditions , behaviors and health symptoms . It includes more than 250 variables on home conditions, outdoor conditions, behaviors, and more than 20 health symptoms. The full list of variables and summary statistics can be found in Appendix A. The second survey was administered to paid participants through the Survey Monkey platform. One of the drawbacks of the survey with paid participants is that it has fewer variables than the survey with volunteer participants.