Limits...
Asbestos exposure among construction workers during demolition of old houses in Tehran, Iran.

Kakooei H, Normohammadi M - Ind Health (2013)

Bottom Line: Air quality in demolition practices has seldom been evaluated in Iran.Personal monitoring of asbestos fiber levels indicated a range from 0.01 to 0.15 PCM f/ml (0.02-0.42 SEM f/ml).Therefore, it might be expected that workers who worked in the demolition of old houses will suffer from negative effects of exposing to the asbestos fibers.

View Article: PubMed Central - PubMed

Affiliation: Department of Occupational Health, School of Public Health, Tehran University of Medical Sciences, Iran.

ABSTRACT
Air quality in demolition practices has seldom been evaluated in Iran. Accordingly, we evaluated asbestos exposure among Tehran construction workers during the demolition of old houses. To identify possible sources of asbestos exposure, including thermal insulations, chimney pipes and cement sheets, were all sampled. This study also were taken the personal air samples to evaluate any asbestos exposure during the demolition. The asbestos fibers found in the samples were analyzed by phase-contrast optical microscopy (PCM), scanning electron microscopy (SEM) equipped with an energy dispersive X-ray analysis, and polarized light microscopy (PLM) methods. Personal monitoring of asbestos fiber levels indicated a range from 0.01 to 0.15 PCM f/ml (0.02-0.42 SEM f/ml). The geometric mean concentrations were 0.07 PCM f/ml (0.20 SEM f/ml), which is considerably higher than the threshold limit value (TLV) proposed by American Conference of Governmental Industrial Hygienist (ACGIH), which is 0.1 f/ml. The analysis showed a presence in the bulk samples only chrysotile asbestos and an absence of the other type asbestos. Therefore, it might be expected that workers who worked in the demolition of old houses will suffer from negative effects of exposing to the asbestos fibers.

Show MeSH

Related in: MedlinePlus

Demolition in progress. (A) during demolition; (B) after demolition and before debrisremoval.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4202766&req=5

fig_001: Demolition in progress. (A) during demolition; (B) after demolition and before debrisremoval.

Mentions: The four demolition sites were selected located within 2–5 km of each other into fourregions of Tehran, the capital city of Iran: (1) the south (S), (2) east (E), (3) west(W), and (4) center (C). Tehran, the capital city of Iran and the regional center ofTehran province, has more than 7 million inhabitants and occupies a surface area of about700 km2, 3). Selection criteria were as come after: demolition was conductedusing typical practices on residential areas built before 1975 and likely to containconcrete framework with asbestos cement sheet and pipe on the year of construction. Site 1was composed 4 separate houses on different street of the south. All 3 houses on the westside of the street and 1 house on the ends of the east side the street were demolishedduring 10−29 June 2010. Site 2 was collected of partial block demolitions carried outduring 18 July till 3 Aug 2010 on a total of 3 houses into east region. Site 3 wasconsisting of 3 houses on the west region and were demolished during 23 Aug till 9 Sep2010. All houses on the sites had been renovated in the early 1970s, except 3 houses onthe east western portion of the region. Site 4 was collected of 3 houses on differentblock of a narrow 4-m wide ally street. Demolition of all 4 houses on the sites occurredin 21th May and 20th July 2011 into center reign. As we know the choice of choosing ademolition method depends the project conditions, site construction, sensitivity of theneighborhood and availability of equipment. Regarding to the sites situation that wassmall with congested space, demolition at each site was carried out by human operatives.In this case, human operatives are used in the demolition process using hand tools, simpleelectrically or pneumatically powered tools such as picks, hummer, wire cutting andwelding cutters (Fig. 1). The number of workersper demolition practices were approximately 3–5 persons. The mean age of workers and meanemployment period of workers were 28 yr and 7 yr, respectively. In general, top-downmethods are used in the four sites, particularly for the situated in the busy urban areas.Demolition will generate huge amount of demolished materials. The safe and effectiveremoval of construction remains such as airborne dust and asbestos fibers will be a primeconcern in the operation. Whole-house demolition was typically done during the course 6 d.In the process, water was not sprayed during demolition and debris removal. The roll-offbins were removed from the site by truck. Demolished materials removal work took 1–2 weeksper site and involved the loading and removal of approximately 14 roll-off bines (thereare 15m3 of debris for each roll-off bin) for each house demolished. At site 1,for example, approximately 80 roll-offs were loaded and removed.


Asbestos exposure among construction workers during demolition of old houses in Tehran, Iran.

Kakooei H, Normohammadi M - Ind Health (2013)

Demolition in progress. (A) during demolition; (B) after demolition and before debrisremoval.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4202766&req=5

fig_001: Demolition in progress. (A) during demolition; (B) after demolition and before debrisremoval.
Mentions: The four demolition sites were selected located within 2–5 km of each other into fourregions of Tehran, the capital city of Iran: (1) the south (S), (2) east (E), (3) west(W), and (4) center (C). Tehran, the capital city of Iran and the regional center ofTehran province, has more than 7 million inhabitants and occupies a surface area of about700 km2, 3). Selection criteria were as come after: demolition was conductedusing typical practices on residential areas built before 1975 and likely to containconcrete framework with asbestos cement sheet and pipe on the year of construction. Site 1was composed 4 separate houses on different street of the south. All 3 houses on the westside of the street and 1 house on the ends of the east side the street were demolishedduring 10−29 June 2010. Site 2 was collected of partial block demolitions carried outduring 18 July till 3 Aug 2010 on a total of 3 houses into east region. Site 3 wasconsisting of 3 houses on the west region and were demolished during 23 Aug till 9 Sep2010. All houses on the sites had been renovated in the early 1970s, except 3 houses onthe east western portion of the region. Site 4 was collected of 3 houses on differentblock of a narrow 4-m wide ally street. Demolition of all 4 houses on the sites occurredin 21th May and 20th July 2011 into center reign. As we know the choice of choosing ademolition method depends the project conditions, site construction, sensitivity of theneighborhood and availability of equipment. Regarding to the sites situation that wassmall with congested space, demolition at each site was carried out by human operatives.In this case, human operatives are used in the demolition process using hand tools, simpleelectrically or pneumatically powered tools such as picks, hummer, wire cutting andwelding cutters (Fig. 1). The number of workersper demolition practices were approximately 3–5 persons. The mean age of workers and meanemployment period of workers were 28 yr and 7 yr, respectively. In general, top-downmethods are used in the four sites, particularly for the situated in the busy urban areas.Demolition will generate huge amount of demolished materials. The safe and effectiveremoval of construction remains such as airborne dust and asbestos fibers will be a primeconcern in the operation. Whole-house demolition was typically done during the course 6 d.In the process, water was not sprayed during demolition and debris removal. The roll-offbins were removed from the site by truck. Demolished materials removal work took 1–2 weeksper site and involved the loading and removal of approximately 14 roll-off bines (thereare 15m3 of debris for each roll-off bin) for each house demolished. At site 1,for example, approximately 80 roll-offs were loaded and removed.

Bottom Line: Air quality in demolition practices has seldom been evaluated in Iran.Personal monitoring of asbestos fiber levels indicated a range from 0.01 to 0.15 PCM f/ml (0.02-0.42 SEM f/ml).Therefore, it might be expected that workers who worked in the demolition of old houses will suffer from negative effects of exposing to the asbestos fibers.

View Article: PubMed Central - PubMed

Affiliation: Department of Occupational Health, School of Public Health, Tehran University of Medical Sciences, Iran.

ABSTRACT
Air quality in demolition practices has seldom been evaluated in Iran. Accordingly, we evaluated asbestos exposure among Tehran construction workers during the demolition of old houses. To identify possible sources of asbestos exposure, including thermal insulations, chimney pipes and cement sheets, were all sampled. This study also were taken the personal air samples to evaluate any asbestos exposure during the demolition. The asbestos fibers found in the samples were analyzed by phase-contrast optical microscopy (PCM), scanning electron microscopy (SEM) equipped with an energy dispersive X-ray analysis, and polarized light microscopy (PLM) methods. Personal monitoring of asbestos fiber levels indicated a range from 0.01 to 0.15 PCM f/ml (0.02-0.42 SEM f/ml). The geometric mean concentrations were 0.07 PCM f/ml (0.20 SEM f/ml), which is considerably higher than the threshold limit value (TLV) proposed by American Conference of Governmental Industrial Hygienist (ACGIH), which is 0.1 f/ml. The analysis showed a presence in the bulk samples only chrysotile asbestos and an absence of the other type asbestos. Therefore, it might be expected that workers who worked in the demolition of old houses will suffer from negative effects of exposing to the asbestos fibers.

Show MeSH
Related in: MedlinePlus