Impact of air quality on the health of present-day workers in an Asbestos roof manufacturing industry, Sri Lanka.

The study's objective was to determine the air quality in an asbestos-related industry and its impact on current workers' respiratory health. Seventy-seven air and 65 dust samples were collected at 5-day intervals in an asbestos roofing sheets production factory in Sri Lanka having two production facilities. Sampling was performed in ten sites: Defective sheets-storage, Production-plant, Pulverizer, Cement-silo, and Loading-area. A detailed questionnaire and medical screening were conducted on 264 workers, including Lung Function Tests (LFT) and chest X-rays. Asbestos fibres were observed in deposited dust samples collected from seven sites. Free chrysotile fibres were absent in the breathing air samples. Scanning Electron Microscopy confirmed the presence of asbestos fibres, and the Energy Dispersive X-ray analysis revealed Mg, O, and Si in depositions. The average concentrations of trace metals were Cd-2.74, Pb-17.18, Ni-46.68, Cr-81.01, As-7.12, Co-6.77, and Cu-43.04 mg/kg. The average Zn, Al, Mg, and Fe concentrations were within 0.2-163 g/kg. The highest concentrations of PM2.52.5 and PM1010, 258 and 387 µg/m3, respectively, were observed in the Pulverizer site. Forty-four workers had respiratory symptoms, 64 presented LFT abnormalities, 5 indicated chest irregularities, 35.98% were smokers, and 37.5% of workers with abnormal LFT results were smokers. The correlation coefficients between LFT results and work duration with respiratory symptoms and work duration and chest X-ray results were 0.022 and 0.011, respectively. In conclusion, most pulmonary disorders observed cannot directly correlate to Asbestos exposure due to negligible fibres in breathing air, but fibres in the depositions and dust can influence the pulmonary health of the employees.

Identification and culturing of cyanobacteria isolated from freshwater bodies of Sri Lanka for biodiesel production.

The present study was carried out to investigate cyanobacteria as a potential source for biodiesel production isolated from fresh water bodies of Sri Lanka. Semi mass culturing and mass culturing were carried out to obtain biomass for extracting total lipids. Fatty acid methyl ester (FAME) or biodiesel was produced from extracted lipid by trans-esterification reaction. FAME component was identified using gas chromatography (GC). Atotal of 74 uni-algal cultures were obtained from Biofuel and Bioenergy laboratory of the National Institute of Fundamental Studies (NIFS), Kandy, Sri Lanka. The total lipid content was recorded highest in Oscillatoria sp. (31.9 ±â€¯2.01% of dry biomass) followed by Synechococcus sp. (30.6 ±â€¯2.87%), Croococcidiopsis sp. (22.7 ±â€¯1.36%), Leptolyngbya sp. (21.15 ±â€¯1.99%), Limnothrixsp. (20.73 ±â€¯3.26%), Calothrix sp. (18.15 ±â€¯4.11%) and Nostoc sp. (15.43 ±â€¯3.89%), Cephalothrixsp. (13.95 ±â€¯4.27%), Cephalothrix Komarekiana (13.8 ±â€¯3.56%) and Westiellopsisprolifica (12.80 ±â€¯1.97%). FAME analysis showed cyanobacteria contain Methyl palmitoleate, Linolelaidic acid methyl ester, Cis-8,11,14-eicosatrienoic acid methyl ester, Cis-10-heptadecanoic acid methyl ester, Methyl myristate, Methyl pentadecanoate, Methyl octanoate, Methyl decanoate, Methyl laurate, Methyl tridecanoate, Methyl palmitoleate, Methyl pentadeconoate, Methyl heptadeconoate, Linolaidic acid methyl ester, Methyl erucate, Methyl myristate, Myristoloeic acid, Methyl palmitate, Cis-9-oleic acid methyl ester, Methyl arachidate and Cis-8,11,14-ecosatrieconoic acid methyl ester. The present study revealed that cyanobacteria isolated from Sri Lanka are potential source for biodiesel industry because of their high fatty acid content. Further studies are required to optimize the mass culture conditions to increase thelipid content from cyanobacterial biomass along with the research in the value addition to the remaining biomass.

Assessment of Airborne Bacterial and Fungal Communities in Selected Areas of Teaching Hospital, Kandy, Sri Lanka.

Nosocomial infections, in lay term known as hospital acquired infections, are caused mainly by airborne pathogens found in healthcare facilities and their surroundings. The aim of this study was to quantify and identify bacteria and fungi in a hospital, which is an understudied area of air quality in Sri Lanka. Air samples were collected in agar medium and petri plates containing sterile filter papers. The number of culturable and total airborne microorganisms was estimated by manual counting and fluorescent microscopy, respectively. The morphologically distant bacteria and fungi were identified by DNA sequencing. The statistical analysis revealed significant variances between studied sites (p < 0.05) where Outpatients Department and Respiratory Unit showed higher levels of airborne microbial load. Culturable microbial count was higher at noon (hospital visiting hours) compared to other sampling periods (after hospital visiting hours) within the hospital. Total count of airborne microbes was found to be the highest during the afternoon. The most sensitive zones such as Operating Theatre and Intensive Care Unit showed considerably higher counts of airborne microbes. Identification by molecular means revealed the presence of human pathogens in the hospital air including Bacillus sp, Micrococcus sp, Pseudomonas sp, Staphylococcu ssp, Exiguobacterium sp, Enterobacter sp, Escherichia sp, Sphingomonas sp, Massilia sp, Kocuria sp, Fusarium sp, and Aspergillus sp. In conclusion, the results from this study indicate that the hospital air was generally contaminated. Therefore, the implementation of proactive policies and strategies are needed to monitor hospital air quality in sensitive zones as well as other areas of the hospitals.

Health risk assessment of heavy metals in atmospheric deposition in a congested city environment in a developing country: Kandy City, Sri Lanka.

This research study which was undertaken in a congested city environment in a developing country provides a robust approach for the assessment and management of human health risk associated with atmospheric heavy metals. The case study area was Kandy City, which is the second largest city in Sri Lanka and bears the characteristics of a typical city in the developing world such as the urban footprint, high population density and traffic congestion. Atmospheric deposition samples were collected on a weekly basis and analyzed for nine heavy metals common to urban environments, namely, Al, Cr, Mn, Fe, Ni, Cu, Zn, Cd and Pb. Health risk was assessed using hazard quotient (HQ) and hazard index (HI), while the cancer risk was evaluated based on life time daily cancer risk. Al and Fe were found to be in relatively high concentrations due to the influence of both, natural and anthropogenic sources. High Zn loads were attributed to vehicular emissions and the wide use of Zn coated building materials. Contamination factor and geo-accumulation index showed that currently, Al and Fe are at uncontaminated levels and other metals are in the range of uncontaminated to contaminated levels, but with the potential to exacerbate in the long-term. The health risk assessment showed that the influence of the three exposure pathways were in the order of ingestion > dermal contact > inhalation. The HQ and HI values for children for the nine heavy metals were higher than that for adults, indicating that children may be subjected to potentially higher health risk than adults. The study methodology and outcomes provide fundamental knowledge to regulatory authorities to determine appropriate mitigation measures in relation to HM pollution in city environments in the developing world, where to-date only very limited research has been undertaken.

Microorganisms and heavy metals associated with atmospheric deposition in a congested urban environment of a developing country: Sri Lanka.

The presence of bacteria and heavy metals in atmospheric deposition were investigated in Kandy, Sri Lanka, which is a typical city in the developing world with significant traffic congestion. Atmospheric deposition samples were analyzed for Al, Cr, Mn, Fe, Ni, Cu, Zn, Cd and Pb which are heavy metals common to urban environments. Al and Fe were found in high concentrations due to the presence of natural sources, but may also be re-suspended by vehicular traffic. Relatively high concentrations of toxic metals such as Cr and Pb in dissolved form were also found. High Zn loads can be attributed to vehicular emissions and the wide use of Zn coated roofing materials. The metal loads in wet deposition showed higher concentrations compared to dry deposition. The metal concentrations among the different sampling sites significantly differ from each other depending on the traffic conditions. Industrial activities are not significant in Kandy City. Consequently, the traffic exerts high influence on heavy metal loadings. As part of the bacterial investigations, nine species of culturable bacteria, namely; Sphingomonas sp., Pseudomonas aeruginosa, Pseudomonas monteilii, Klebsiella pneumonia, Ochrobactrum intermedium, Leclercia adecarboxylata, Exiguobacterium sp., Bacillus pumilus and Kocuria kristinae, which are opportunistic pathogens, were identified. This is the first time Pseudomonas monteilii and Ochrobactrum intermedium has been reported from a country in Asia. The culturable fraction constituted ~0.01 to 10%. Pigmented bacteria and endospore forming bacteria were copious in the atmospheric depositions due to their capability to withstand harsh environmental conditions. The presence of pathogenic bacteria and heavy metals creates potential human and ecosystem health risk.

Polymerase chain reaction - restriction fragment length polymorphism analysis for the differentiation of mycobacterial species in bronchial washings.

OBJECTIVES: To identify mycobacterial species in bronchoscopy specimens with a simple assay based on polymerase chain reaction and restriction enzyme digestion. METHODS: Sputum smear negative, bronchoscopy specimens (n=202) were collected from patients attending the Central Chest Clinic and the Teaching Hospital Kandy, Sri Lanka. DNA, extracted from the mycobacterial cultures (n=43) were amplified using known mycobacterial specific Sp1 and Sp2 primers. Resulting products were digested with HaeIII and CfoI restriction enzymes and DNA sequencing was performed for the selected isolates. RESULTS: Among the culture positive patients, PCR was able to distinguish 12 rapid growers (~280-320 bp), 15 slow (~200-220 bp) and 10 patients having both rapid and slow and one having two rapid growing mycobacteria. DNA Sequence analysis revealed the presence of M. intracellulare (n=3), M. phocaicum (n=7), M. tuberculosis complex (n=13), Nocardia (n=2), M. smegmatis (n=1) and Mycobacterium sp (n=12). The identified organisms got digested upon exposure to HaeIII restriction enzyme whereas when exposed to CfoI, only M. phocaicum yielded 80 bp and 230 bp DNA fragments while others remained undigested. Consequently, six patients were confirmed to have M. tuberculosis complex, seven had both M. tuberculosis and non-tuberculosis bacteria (NTM) in their bronchoscopy specimens while 21 had NTM. CONCLUSIONS: Optimised PCR-RFLP assay was able to differentiate M. tuberculosis complex bacteria from nontuberculosis mycobacteria and Nocardia. Molecular analysis confirmed the presence of NTM in bronchoscopy specimens and according to the study a significant proportion of patients (13% to 14%) of the study population were found to have NTM in their bronchial washings.

Patterns of drug resistance and RFLP analysis of Mycobacterium tuberculosis strains isolated from recurrent tuberculosis patients in Sri Lanka.

The aim of the study was to determine drug sensitivity and DNA fingerprints of Mycobacterium tuberculosis strains from retreatment cases of pulmonary tuberculosis. The study population consisted of 131 culture positive, retreatment tuberculosis patients admitted to the Chest Hospital, Welisara, Sri Lanka who had taken anti-tuberculosis drugs previously. Forty-eight percent of the isolates were susceptible to all 12 drugs tested. Twenty isolates were resistant to first line drugs, 28 to both first and second line drugs and 17 to second line drugs. Forty-six percent were resistant to a single drug, 23% to two and 19% to 3 drugs, respectively. Resistance to p-aminosalicylic acid (15%) was most common followed by ethambutol (14%), isoniazid and pyrazinamide (12%). Multi-drug resistance was present in four isolates. Using RFLP analysis the copy number and IS 6110 element in M. tuberculosis strains varied from one to seven, the majority having 3 to 5 copies. The prevalence of acquired drug resistance to individual drugs was comparatively lower except resistance to ethambutol. The majority of retreatment patients belonged to the defaulter category and this stresses the importance of implementing directly observed treatment short course and susceptibility testing of isolates in retreatment TB patients to prevent the spread of drug resistance. By using the IS 6110 genetic marker it was possible to differentiate most of the M. tuberculosis isolates. However, for an unambiguous confirmation of the identities of strains, additional genetic markers should be employed in strain typing such as spoligotyping.