During the winter season, people mostly spend their time indoors. The outdoor activity is at a minimum. Obviously, it becomes essential to know the potential contaminants/allergens of the indoor environment.

These contaminants/allergens may be a risk factor from a building-health and hygiene point of view. The identification and quantification of these entities is essential in order to maintain a good indoor environment. In winter, due to low temperature and low humidity most of the micro-organisms are in their dormant phase. However, growth is imminent, even under the harsh environmental conditions. It has been well proven that water is one of the essential factors for life. Although the availability of water has gone down during this time, it is also a good time to spur the microorganisms to disseminate their spores during these drier months. If these spores or other plant and animal bond materials come into the indoor environment, they may be problematic. It is in this context, the following steps are suggested to manage a good indoor environment during winter.

Investigating Indoor Environment

A comprehensive understanding of building-related problems may be determined by knowing information on dwellers, physical and biological factors, and the building situation apart from prevailing environmental conditions. In order to address the above issues for providing hygienic and healthy dwelling conditions, a proper investigation by formulizing a good hypothesis is of a high importance.

Viruses, mycoplasma, bacteria, fungi, protozoa, and other plant and animal-borne particulates, along with other a-biological materials, are identified as common contaminants/allergens of indoor environments. The major microbiological and health related problems in an indoor environment are the proliferation of microorganisms, such as bacteria and fungi. Bacteria and fungi both have three major requirements for their growth, i.e. water, nutrients and proper temperature, besides other environmental and biological aspects. The presence of these microorganisms is often linked with the building-related symptoms (BRSs). Apart from the presence of bioaerosols (such as, bacteria and fungi) mycotoxins, indotoxins, and other indoor toxins, besides several chemicals and physical aspects like volatile organic compounds (VOCs), damp and moist environments, etc. are important contributors, which are directly or indirectly impacting indoor environments.

Root cause investigation of an indoor-related problematic environment can be initiated with a thorough walk-through with steps as simple as "look, see, and smell" in the first stage. The environmental sample collection and their analysis yield some important information on the presence of building contaminants. There are numerous ways to investigate a building for finding the odds responsible for building health and hygiene. Even though not one common master plan fits into every need, it is essential to have some strategy to pinpoint the problems that are related to indoor environments. These include, but are not limited to, hypothesis development, a walk-through, sample collection, use of existing guidelines, other health and hygiene-related information and their correlation with existing conditions. 

Apart from biological factors (proliferation of micro-organisms and their products) other conditions, such as unsuitable ventilation system design, moist and damp environments, etc are important and can influence building health and hygiene. However, inadequate ventilation rates, improper ventilation system maintenance, off-gassing of volatile compounds from building materials and furnishings, as well as the omission of a multitude of airborne substances from occupant activities, and accumulation of dust containing biological agents are some of the minute details that are often overlooked.

Ideally, a baseline development is an important factor for the root cause analysis. During the winter season, due to low temperature and less humidity, the proliferation of the microorganisms and other environment-related issues are less prevalent. Therefore, this period is one of the best times of the year to consider preemptive actions for baseline development.

Some comprehensive steps are important and are recommended to initiate a baseline development, which may serves as a proactive measure to managing a good indoor environment for superior health and hygiene. These steps can be initiated by using do-it-yourself (DIY) test kits, or by seeking professional help.

Dr. Rajiv R. Sahay is a Certified Indoor Air Quality Professional (CIAQP) and Laboratory Director at EDLab at Pure Air Control Services Inc. in Clearwater, Florida, USA.