Biomedical Research

Abstract

Various health problems including symptoms and diseases are known to be associated with microbially contaminated air and can arise through inhalation of airborne fungal spores. The relationship between the viable air floating fungal contamination and the respirable particulate matter with aerodynamic diameter less than 10 μm (PM10) in the ambient air was studied. Samples were collected at each sampling period (10 sites in total) at residential, commercial cum traffic and Industrial sites in the city of Lucknow (Uttar Pradesh) during April, 2010 to June, 2011. The respirable dust sampler (Environtech Model APM 460 NL) was used for the collection. 6 groups of fungi of environmental origin were detected on PM10.The concentration of airborne fungi was increased with increasing mass concentration of PM10.

Keywords

RSPM, PM₁₀, urban traffic, inhalable particles, fungal contamination, health

Introduction

Airborne particles in the air that can be aspirated into the nose or mouth during normal breathing are known as "inhalable particles." Inhalability decreases gradually with increasing particle diameter, reaching a level of about 50 percent at 100 microns (μm). "Subfractions" of the inhalable fraction are the particles that can penetrate through the upper respiratory tract (head airways) and enter the thoracic airways (lower respiratory tract). The aerodynamic particle diameter for 50 percent penetration into the thorax is 10 μM, and air samplers that mimic this penetration are used to determine PM₁₀ (particulate matter of 10 micrometers [microns] or less in diameter), or thoracic particulate matter standards. Particulate matter is the term used to describe particles that are suspended in the air. Particles may be solid or liquid and are one of the most obvious forms of pollution as they are visible in the hazes that cover a city or region. Size is the main determinant of the behavior of an atmospheric particle. The size is usually in terms of the ‘aerodynamic diameter’ which refers to unit density of spherical particles with the same aerodynamic

properties such as falling speed. Smaller particles (less than 10 μm, known as PM₁₀) can remain in the air for several days and can be spread by winds over wide areas or long distances from the original source. These particles (PM₁₀) are known as inhalable or breathable particles may penetrate deeply in the thoracic region of the lungs, where the toxic effect is most serious. They are generated by diesel and petrol motor vehicles and other combustion processes that burn fossil fuels such as power generation, industrial processes and domestic solid fuel heater. Various health problems, including respiratory symptoms and diseases, are known to be associated with microbially contaminated air and can arise, for example, through inhalation of airborne fungal spores. Major concerns for human health from exposure to PM₁₀ include: effect on breathing and respiratory system damage to lung tissue, cancer and premature death. Biological particles like bacteria, fungi and pollen are a part of the particle load found in indoor and outdoor air. Fungal spores commonly called mold spores are a normal component of the outdoor air. They are present in the atmosphere anytime that the ground is not covered with ice or snow. The spores are discharged from fungi growing as saprophytes (existing on dead or decaying organic matter is the soil or elsewhere in the environment) or parasites (infecting living tissues - most are plant pathogens).Many fungal spores (possibly all) are allergenic, capable of causing allergic responses in susceptible individuals. A small group of fungi are also human pathogens. While many human pathogens just cause mild or annoying conditions, such as athlete's foot and ringworm, other human pathogens can cause severe and debilitating diseases. Air borne microbes, allergens and chemicals cause respiratory disease, inflammation in the nose, throat, sinuses, upperway &the lung. The best way to utilize this study guide is to understand the characteristics by description & be familiar with the visual representation of the fungus on RSPM [1]. Some biological contaminants trigger allergic reactions, including hypersensitivity pneumonitis, allergic rhinitis and some type of asthma [2, 3, 4]. These contaminants may irritate the skin of humans & contribute to symptoms, such as, headache, fatigue, eye and/or nose and/or throat irritation [2]. Many infections are acquired by inhalation of pathogens that may remain in the respiratory system but also invade the rest of the body through lymphatic and blood circulation. This study therefore aimed to investigate identifies the fungal contamination present on respirable suspended particulate matter (RSPM/PM₁₀) in urban areas of Lucknow.

Material and Methods

Ten locations air samples (for fungal) were collected and analyzed. The maximum microbial load was in Aminabad whose optical density at 600 nm was 1.903. Indian Institute of Toxicology Research, Lucknow has set up air monitoring station network at 10 sites and 24 hours continuous air monitoring for PM₁₀ was carried out. The nature of ten monitoring sites represent residential areas (Ali ganj, Vikas Nagar, Indira Nagar, Gomti Nagar); Commer cial areas (Hussainganj, Charbagh, Alambagh, Aminabad, Chowk); and Industrial area (Amausi). Outdoor air PM₁₀ samples were collected from the respirable dust sampler (Environtech Model APM 460 NL). It was installed at a height of 4 ft above ground level at each sampling site. Samplers were operated round to clock (24 h) with a replacement of fresh filter every 8 hrs for PM₁₀ glass fibre filter (EPAM-2000, size 8*10 inches) was used weighed on 5 digit digital balance before & after sampling. The weight difference of filters between pre & post sampling was used to calculate the mass of particulate matter. Samples were collected from ten PM₁₀ glass filters on sterile swabs & were inoculated separately in liquid broth (Robertson Cooked Media). Fungi specimens were inoculated on Sabouraud 2% dextrose agar [5] and were incubated for 7-21 days at 25°C with daily observation. They were isolated & identified by cultural characteristics like different growth of rate & appearance of growth, pigment production, morphology like hyphae, branching pattern & structure of asexual spores.

Results

Ten sterile swabs sticks are touched on PM₁₀ glass filters are immersed in the liquid media (Robertson Cooked Media) and keep it in the incubator for 72 hours at 37° C for the growth of bacteria. After 72 hrs the samples are taken out and O.D. is taken at 600 nm of each sample with the help of spectrophotometer.The maximum O.D. was found in spectrophotometer at commercial cum traffic area i.e., at aminabad followed by gomti nagar. 6 groups of fungi of environmental origin were detected on PM₁₀. Fungi i.e., Epicoccum, Chaetomium, Chyrosporium spp., Aspergillus fumigatus & Aspergillus tereus, Philaphora verrucosa were found on PM₁₀ (Table 1).

Table 1: Fungal contamination present on RSPM/PM₁₀.

Discussion

The objective of this study is to show the association of PM₁₀ and microbial pollutants and their affect on human respiratory health. We have shown that the microbes that are present on inhalable particles i.e.,PM₁₀/RSPM are responsible for various adverse affects on human health. Air pollution is commonly perceived as an urban problem associated with motor vehicles and industries. Deteriorating air quality is a major environmental problem in many large urban areas

in both developed and developing countries. Phialophora verrucosa is the principal causative agent of chromoblastomycosis in tropical and subtropical areas, particularly at Japan and South America. The health effects of biomass smoke inhalation may not be restricted to the lungs because biomass smoke contains fine and ultrafine particles [6] that readily cross the alveolar-capillary barrier and reach vital organs of the body through circulation (7).Motor vehicle exhausts also produce particulate matter (PM₁₀) in outdoor air [8,9,10]. A previous study showed particulate levels correlated with aerosols levels because the dust had microbials attached [11].A study in Korea found four airborne fungi: Fussarium spp., Aspergillus spp, Penicillium spp, and Basipetospora spp [12]. These may affect human health, especially traffic police and street venders, who spend most of the working time in high density traffic areas. When inhaled in sufficient concentrations they tend to produce acute neutrophilic airway inflammation associated with symptoms consisting of cough, bronchorrhea, dyspnea and wheezing [13]. Airborne microbes, allergens and chemicals cause respiratory disease, inflammation in the nose, throat, sinuses, upper airway and the lung. Many infections are acquired by inhalation of pathogens that may remain in the respiratory system but also invade the rest of the body through lymphatic and blood circulation [14].

References

1. Kristina LS. Microbiology Study Guide: Understanding the Bacterial Cell Structure 2010. Bright hub.
2. WHO (World Health Organization). Indoor air quality: Biological contaminants. European Ser 1990; 30: 374- 85.
3. Zweers T. Health and indoor climates complaints of 7,043 office workers in 61 building in the Natherlands. Indoor Air 1992; 2: 127-136.
4. Homer WE, Helbling A, Salvaggio JE, Lehrer SB. Fungal allergens. ClinMicrobiol Rev 1995; 8: 161-79.
5. Nemmar A, Hoet PH, Vanquickenborne B, Dinsdale D, Thomeer M, Hoylaerts MF, Vanbilloen H, Mortelmans L, Nemery B. Passage of inhaled particles into the blood circulation in humans. Circulation2002; 105: 411-414.
6. Larone DH. Medically important fungi: A guide to identification. 3rd ed. Washington, DC: American Society of Microbiology Press 1995; 1-274.
7. Tesfaigzi Y, Singh SP, Foster JE, Kubatko J, Barr EB, Fine PM, McDonald JD, Hahn FF, Mauderly JL. Health effects of subchronic exposure to low levels of wood smoke in the rats. Toxicological sciences: an official journal of the Society of Toxicology 2002; 65 (1): 115-125.
8. Meychting M, Svensson D, Ahlbom A. Exposure to motor vehicle exhaust and childhood cancer. Scand J Work Environ Health 1998; 24: 8-11.
9. Raaschou- Neilsen O, Hertel O, Thomsen B L, Olsen J H. Air pollution from traffic at the residence of children with cancer. Am. J. Epidemiol, 2001; 153: 433- 443.
10. Lee CC, Chen MR, Shih TS, Tgai PJ, Lai CH, Liou SH. Exposure assessment on volatile organic compounds (VOCs) for tollway station workers via direct & indirect approaches. J Occup Health 2002; 44:294-300.
11. Jacobs RR. Risk environments. In: Rylander R, Jacobs RR, eds. Organic dusts: exposure, effects and prevention. USA: Lewis, 1994: 3-15.
12. Yeo HG, Kim JH. SPM and fungal spores in the ambient air of West Korea during the Asian dust (Yellow sand) period. Atmos Environ 2002; 36: 5437-42.
13. Laffon M, Pittet JF, Modelska K et al. Interleukin 8 mediates injury from smoke inhalation to both the lung epithelial and alveolar epithelial barriers in rabbits. American journal of respiratory and critical care medicine 1999; 160: 1443-1448.
14. Tyagi S, Tyagi PK, Pandey CS, Kumar R. Bacterial contamination: A comparison between rural and urban areas of Panipat district in Haryana (India). Journal of Bacteriology Research 2011; 3(3): 32-41.