(7.3.602) BE AWARE! INDOOR AIR POLLUTION MAY LEAD TO OCCUPATIONAL HEALTH HAZARD Dr. Ashutosh Kumar, G.C. Raturi, NN Ray* & Dr. T. Chakraborti* Vigilance Section Oil and Natural Gas Corporation Limited 108-Vasudhara Bhawan Bandra (E), Mumbai-400 097 *Institute of Petroleum Safety Health and Environment Management ONGC, Betul, Goa Abstract:

The productivity of any enterprise depends upon the health condition of its employees. The work centers with polluted indoor atmosphere can adversely affect the working efficiency and health of the workers. It can also have long-term impact on the individuals. The indoor air pollutants primarily consist of dust particulates, moisture, and gases like Carbon dioxide, Carbon monoxide, Nitrogen dioxide, semi volatile organic compounds e.g. PCB, Dioxins etc. The basic difference in indoor and outdoor pollution lies in the sources and the magnitude of pollutants concentration. The indoor pollution arises from both human and natural activities. The indoor pollutants from natural processes are moisture content, biological aerosols, allergens and the radon gas.

The indoor air pollution may lead to a serious health hazard to the personnel working on both the onshore and offshore oil industry work centers. Studies show that the concentration of indoor air pollutants such as carbon dioxide, carbon-monoxide, nitrogen dioxide, formaldehyde, etc. are often found to be higher than the outdoor concentration in buildings and structures lacking in proper ventilation. The indoor pollution arises from both human and natural activities. The indoor pollutants from natural processes are moisture content, biological aerosols, allergens and the radon gas. The biological aerosols are formed from the bacteria, which are generated in heating, ventilation and air conditioning systems. Allergens originate from the plant origin and are carried by winds and find their way inside the buildings. Radon gas- a naturally occurring radioactive gas migrates up from soil and rock in to basements and lower floors of the houses. Sometimes the bricks, which are used as building materials also, contain radon. The anthropogenic sources of indoor pollutants originate from the material and appliances used for inside walls, finishing materials and appliances used for decoration of the households. The prolonged exposure to these pollutants may cause headache, nausea, asthma etc. In cases of extreme eventualities it may be fatal. Hence the indoor air pollution monitoring should be essentially carried out at the worksites to estimate the concentration of air pollutants so that preventive and control measures may be undertaken on time to safeguard the personnel from the deleterious impact of indoor air pollutants. Hence there is an urgent need for the monitoring of indoor air pollutants at all the industrial worksites where the personnel spend most of their time working inside the confined/closed rooms/ structures. This will help in detecting the concentration of indoor air pollutants so that preventive and control measures may be undertaken in time if the concentrations of the pollutants are found to be beyond the permissible limit.

This paper analyzes the various aspects of indoor air pollutants and their effects on occupational health. On the basis of studies, it is recommended to have the indoor air quality monitoring of all the work centers to plan necessary preventive and remedial action in time.

Introduction:

A great effort is being made these days to control & prevent the outdoor pollution both by the government and the industrial enterprises all over the world .The pollution emission limits have been regulated and industries are striving hard to achieve zero discharge of pollutants in order to protect the human being and the ecosystem from the menace of deadly pollutants. However, the potential of air pollution threat one has to face sitting inside the office /working centers/living quarters are much severe than the outdoor pollutants. The indoor air pollutants concentration is found to be several times higher than the outdoors

air pollutants. The indoor air pollutants primarily consist of dust particulates, moisture, gases like Carbon dioxide, Carbon monoxide, Nitrogen dioxide, semi volatile organic compounds e.g. PCB, Dioxins etc. which are also the components of outdoor pollution. The basic difference in indoor and outdoor pollution lies in the sources and the magnitude of pollutants concentration. The indoor pollution arises from both human and natural activities. The indoor pollutants from natural processes are moisture content, biological aerosols, allergens and the radon gas. The biological aerosols are formed from the bacteria, which are generated in heating, ventilation and air conditioning systems. Allergens originate from the plant origin and are carried by winds and find their way inside the buildings. Radon gas- a naturally occurring radioactive gas migrates up from soil and rock in to basements and lower floors of the houses. Sometimes the bricks, which are used as building materials also, contain radon. EPA has set the limit for Radon radiation at 4 Pci / L. The anthropogenic sources of indoor pollutants originate from the material and appliances used for inside walls, finishing materials and appliances used for decoration of the households. Potential indoor air pollutants: The indoor air pollutants, which are generally found to be present inside the building/ structures in very high concentrations, can cause serious health hazards to the occupants. The high Indoor moisture contents along with high temperature not only cause laziness but provide conducive environment for the growth of microbes also. Formaldehyde, one of the widely found indoor pollutants that is usually one of the building materials for most of the ply woods and the bonding material for particle board and wood panels, is a probable carcinogen .It causes discomfort to eyes, nose, throat and skin at levels slightly higher than 0.1 ppm. Severe headache and dizziness among the individuals exposed to higher levels of formaldehyde have also been reported. At much higher concentration of Formaldehyde breathing becomes difficult. The ambient air Formaldehyde levels range from 0.2 ppm on pacific island to 2 ppb in troposphere. In USA the occupational level of Formaldehyde has been set at 0.05 4 ppm. The new Urea-Formaldehyde bonded interior grade plywood with an emission rate of Formaldehyde up to 34mg/m3 and the particleboard having emission rate up to 25mg/m3 are also being used in some of the buildings. Asbestos, one of the building materials of most of the insulating substances used for making the rooms/buildings energy efficient, has been found to be responsible for a particular type of lung cancer. Asbestos consists of distinct needle like fibers of which those that are 0.1- 0.5 micro meters in size are readily respired and absorbed in the lung and subsequently migrate to lymph ganglions where they remain permanently as latent irritant. The asbestos products release these fibers, which remain airborne and pose a serious health threat to the occupants of the building. Risk assessment compiled by the EPA in 1979 showed a significant risk for all those who are exposed to more than five fibers per millimeter of air for any length of time. The risk is highest for people who live or work in buildings with friable asbestos tiles or insulation.Apart from the pollutants that are released in the indoor atmosphere from the appliances used for interior decoration or insulation purposes, some common outdoor air pollutants are also found in very high concentration in the indoor air and which are as follows: Nitrogen oxide: It is soluble in biological tissues and is an oxidant .At higher concentrations it affects the respiratory system. According to EPA reports in 1976 in Czechoslovakia children of age group 7-12 years when exposed to NO2 concentration of 20- 70 micrograms were observed to have two-fold excess in acute respiratory disease than the unexposed group. Carbon monoxide: An odorless gas has average indoor concentration of few ppm only. But high concentration of this gas may cause headache, fatigue, unconsciousness and eventually death. Sulphur dioxide: It is a reactive gas and fully mixes with air at all temperatures. It dissolves in water and is absorbed by and reacts with particleboard, gypsum board and many type of furnishings. It also dissolves in water adsorbed on surfaces and subsequently oxidizes to form sulphate particulate in presence of active particulate surfaces. The sulphate particulates are respirable and are known to cause

Asthma and other respiratory complications. The natural sulphur dioxide levels are found to be below 0.1 ppm. Carbon dioxide levels for indoor pollution in occupied rooms are found to be higher than outdoor levels since the human metabolism produces about 5 ml co2/min. The indoor concentration of carbon dioxide has been found in the range of 50- 1200 ppm. However, the recommended 8 hours carbon dioxide concentration is 500 ppm. The higher concentration of carbon dioxide may cause suffocation and in the event of extreme eventualities even death may occur. Radon seepages: Many rocks and granite soil contain Uranium, which is a radioactive element. The 14-step sequence of decay of U- 238 includes Radon- a gaseous element. The immediate precursor of the radon is Radium-226, having a half-life period of 1600 years and which decays by emission of an Alfa particle Ra Rn + He Ra- Radium Rn- Radon He- Helium The Radon isotope has a half-life of 3.8 days. Radon gas mostly seeps through the holes and cracks in the basements of the homes. The intake is increased significantly if the air pressure in the basement is low. Surprisingly the very small background concentration of radon in air is responsible for about half of the total exposure of radioactivity to the human being. Radon gas is chemically inert under ambient conditions and remains a monatomic gas. In fact Radon gas does not pose much of a danger to the human being. The danger arises because of the radioactivity arising from the three elements produced in sequence during the disintegration of radon namely Polonium, lead and Bismuth. In microscopic amounts these elements are solid and when formed in air from Radon they quickly adhere to dust particles which when inhaled adhere to lungs and pose a health threat. In addition to this Polonium-218 and Polonium-214 that are produced from the decay of Radon-226, emit energetic Alfa particles that can cause radiation damage to the bronchial cells near which the dust particle reside. This damage can eventually lead to lung cancer. The sequence of radioactive decay of Radon is as follows RaRnPoPbBiPoPbBi Studies show that the exposure to Radon is the second leading cause of lung cancer. Radon gas exposure is also linked to different forms of cancer such as melanoma (a deadly form of skin cancer) and leukemia. The EPA has set action levels for Radon radiation at 4 Pci/L. Sources and impact of indoor air pollutants: Indoor Air Pollutants Sources Effects

Ammonia Tobacco smoke Eye/skin irritation, headaches, nose bleeds, sinus problems

Benzene Paint, new carpet, new drapes, upholstery

Headaches, eye/skin irritation, fatigue, cancer

Benzopyrene Tobacco smoke Asthma attacks, eye/skin irritation, sinus problems, lung cancer

Xylene Paint, new drapes, cleaning supplies, new carpeting

Headaches, dizziness, fatigue

Trichlorethylene Paints, glues, furniture, wallpaper

Headaches, eye/skin irritation, respiratory irritation

Hydrocarbons Tobacco smoke, gas burners, furnaces

Headaches, eye/skin irritation, nausea, breathing difficulties

Formaldehyde Tobacco smoke, plywood cabinets, furniture, particle board flooring and furniture, office dividers, new carpet, new drapes, wallpaper, paneling

Headaches, eye/skin irritation, drowsiness, fatigue, respiratory problems, memory loss, depression, gynecological problems, cancer

Common Particulate indoor Pollutants

Dust Carpet, clothing, pollen, dirt, paint, upholstery animal, industrial processes and human skin

Eye irritation, allergies, eye-ear, nose & throat infections, asthma attacks, fatigue, depression

Common Bioactive indoor air Contaminants:

Bacteria & Viruses Air conditioning/heating ducts, pets, garbage, bathroom, water, food & air

Colds, flu, respiratory infections, eye infections

Genus Klebsiella Air, saliva, urine Chronic infections spec. Urinary tract, severe hemorrhagic pneumonia

Bacillus subtilis Common in soil, decomposing matter, dust, air

Infections of wounds and eye

Legionalla pneumophila Air conditioning ducts legionellosis and Pontiac Fever

Sick Building Syndrome (SBS): The presence of indoor air pollutants in the building/ structures may cause illness to the occupants, which is known as Sick building syndrome, a controversial illness that ranges in severity from minor annoyances to chronic debilitating disorders that can force a person to vacate a job and can severely impact one's quality of life. According to the Occupational Safety & Health Administration concern over indoors air quality increased in the 1970s when energy conservation measures in office buildings minimized the infiltration of outside air, contributing to the buildup of indoor air contaminants. "The U.S. Environmental Protection Agency (EPA) defines SBS as a `situation where building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified'. When an illness is diagnosed and the symptoms are attributed directly to airborne building contaminants, the U.S. EPA uses the term `building-related illness' (BRI)."Indicators of SBS include symptoms associated with acute discomfort, such as headaches; eye, nose or throat irritation; dry cough; dry or itchy skin; dizziness and nausea; inability to concentrate; and fatigue. Even though the direct cause of the symptoms is unknown, most sufferers report experiencing relief when they leave the building. Although BRI has similar symptoms cough, chest tightness, fever and chills, and muscle aches these symptoms can be clinically defined and there causes clearly identified. Also, in cases of BRI, patients often complain of a delayed recovery time after leaving the building.

The real cause of SBS is attributed to the indoor air pollutants. Some common air pollutants include carbon monoxide and other contaminants entering the building through air-intake vents that are connected to exhaust-filled loading docks and parking garages. Similarly, the stack effect, which occurs when cigarette smoke gets sucked back into a building through revolving doors, is a hazard to building occupants. Other potential SBS culprits are building materials including those in office furniture and equipment and pesticides that emit volatile organic compounds (VOCs). These organic chemicals have been implicated as a cause of multiple chemical sensitivity (MCS), a controversial disease that can make people allergic to almost anything containing a synthetic chemical."

Historically, complaints associated with SBS were regarded as superfluous whining from lazy employees. But the 1976 outbreak of a mysterious lung ailment during an American Legion Convention held at the Bellevue-Stratford Hotel in Philadelphia forced the public to question the health effects of indoor air contaminants. The outbreak, which came to be known as Legionnaires' disease, was due to the presence of a contaminating bacterium, Legionella pneumophila, in water used to cool the hotel's air-conditioning system. Thirty-four people died from the infection and 221 were infected. This incident and others that ended up in the legal arena in the USA and began forcing employers to look at the construction and environmental management of office .In USA, local and state governments are recognizing the damaging

effects of SBS and MCS and are forcing employers to accommodate sufferers, in addition to making employers responsible for providing social benefits in the form of compensation and medical assistance. Do we have a healthy indoor air environment at industrial work centers: In the offshore industrial work centers personnel spend most of their time staying inside the confined structures, which are either closed AC working place or AC living bunkhouses. These confined structures usually made of iron sheets with proper inside insulation to make it energy efficient. The internal walls of these structures in addition to the beds, working tables etc. are made of plywood. Both the insulating materials and the plywood used for the above purpose may contain pollutants like Formaldehyde or asbestos as one of their building materials. Under high moisture conditions, these pollutants are released and may adversely affect the health of the occupants. Further the exhaust gases from the running engines, the smoke released during the cooking of foods and smoking and the vapors from the evaporation of chemicals from different chemical processes find their way inside the indoor environment. This may significantly raise the indoor concentration of noxious gases like CO2, NOx, CO, etc. The situation may worsen if the AC systems do not function efficiently. The effectiveness of AC system depends on the proper design of the equipment relative to the building, on installation and on correct maintenance and operating procedures. If any one of these factors concentrates pollutants, it may give rise to serious indoor pollution problems. The AC equipment sometimes harbour the disease carrying bacteria in air ducts and filters which leads to the outbreak of Legionnaires disease. The AC system transports the bacteria through the building as a bacterial aerosol when the AC system is put on. On the onshore work centers, the indoor air pollution level may be almost of the same nature and magnitude as discussed above. However, the onshore working centers have additional sources of indoor air pollutants. These are the dust particles generated due to the movement of heavy vehicles, tankers, cranes etc. that get concentrated inside the working place and the radon gas which may seep through the cracks in the floor of the buildings/offices. In one of the studies carried out in USA the radon level of 3200Pci/L has been found in one of the house holds where as the maximum permissible limit set by EPA for exposure to the Radon radiation is only 4Pci/L Conclusions: Thus there is an urgent need for the monitoring of indoor air pollution at all the industrial work centers. These monitoring will not only be helpful in the prevention and control of indoor air pollution but can provide the data and analytic framework for accessing cumulative effects. In addition to this it will also improve forecasting methods by comparing the actual effects to the predicted effect. Investments towards maintenance of indoor air quality free of air pollutants may put additional cost burdens on the companies but studies show that such measures pay off in the long run and result in higher worker productivity and decrease in workers sick leave. In addition to this it raises the moral of the workers who appreciate that the company really care for them. Acknowledgements: Authors are thankful to Sh. Swadeep Singh, IAS Chief Vigilance Officer, ONGC for his constant encouragement and guidance during preparation of this paper. Thanks are also due to Sh. NK Mitra, GGM-Head Vigilance for his valuable discussions and suggestions. References: 1. Indoor Air Quality: Beat Meyer 2. Air Pollution: M.N. Rao

Dr. Ashutosh Kumar, G.C. Raturi, NN Ray* & Dr. T. Chakraborti*Indoor Air Pollutants Sources Effects