Measurement of Air Quality during a Decorating Engineering

Air quality studies during a decorating engineering in northern Taiwan were carried out. Sampling was undertaken during the decorating engineering including the dismantling old decorating, water and electrical pipe engineering, tiling engineering, window installation, pre-system furniture installation, flooring engineering, postsystem furniture installation and finishing engineering. The levels of carbon monoxide (CO), carbon dioxide (CO2), formaldehyde (HCHO), temperature, relative humidity and bacterial/fungal concentrations were recorded during the decorating engineering. Results show that the averaged CO concentrations ranged from 1.05 to 22.1 ppm during various engineering. The averaged HCHO concentrations ranged from 0.08 to 0.69 ppm and the HCHO increased apparently after system furniture installation. The averaged PM2.5 and PM10 concentrations ranged from 97.2 to 6,445 μg/m and 129 to 6,837 μg/m, respectively. The PM concentrations for the tiling engineering were more than two times of the recommended exposure limit (REL) of respirable particles of 5 mg/m. The mean respirable fractions, Rb and Rf, for bacteria and fungi, ranged from 27.8%–97.0% and 29.4%–93.8%, respectively. It should be noticeable that over 75% of Rb and Rf were higher than 50% during the decorating engineering. The relatively high respirable fractions of bioaerosols and the high PM concentrations for some specific decorating engineering probably implies a higher adverse health risk for sensitive workers. There are limited information about the air quality for the decorating engineering and this preliminary study can provide references to the Taiwan government on air quality management for workplaces.


INTRODUCTION
mapping global ground-level PM 2.5 concentrations made people around the world deeply impressed by the health impact of air pollutions.WHO reports that around 7 million people died in 2012-one in eight of total global deaths -as a result of air pollution exposure (WHO).Pope et al. (1995) indicated particulate air pollution was associated with cardiopulmonary and lung cancer mortality.There should be more focused on the indoor air quality.Because many people might spend up to 90 % of daytime indoors whatever at home, work or school.WHO also reminded a total of 3.3 million deaths linked to indoor air pollution and 2.6 million deaths related to outdoor air pollution in the WHO South-East Asia and Western Pacific Regions (WHO).The quality of the air we breathe indoors pose a strongly direct impact on our health (Bruce et al., 2000).
Many people are aware of the environmental health risk by air pollutions, especially the indoor air pollutions.Most of the studies investigated the indoor air quality of offices (Lee et al., 2002;Fang et al., 2004), houses (Bruce et al., 2004;Taneja et al., 2008), hospitals (Nordstrom et al., 1995;We Jr., 1993), shopping malls (Li et al., 2001), dental clinics (Godwin et al., 2003;Helmis et al., 2007) and classrooms (Lee and Chang, 1999;Daisey et al., 2003).People pay more and more attention on the exposure under new decorated house.However, the information of air quality for a decorating workplace is very limited and it's probably much worse for the working labor.Liu et al. (2012) indicated if children moved to the new interior decoration house as soon as possible, therefore, the proportion of having cough, sputum and asthma will increase.Mo et al. (2012) investigated 30 residential buildings and 5 office buildings after decorating in Guangxi Nanning city for formaldehyde, benzene, total volatile organic compounds (TVOC), ammonia and radon.80.0% of the measured building for TVOC concentration exceed the national standard.Some VOCs, including formaldehyde, in combination might result in sensory irritation under certain environmental and occupational conditions.The TVOCs, PM, O 3 , CO HCHO are always the measurement targets for most sampling sites, but the bacterial and fungal concentrations are often excluded.
This study was to evaluate the air quality of a decorating workplace during the decorating engineering.The distribution of air quality during the decorating engineering was monitored and compared.This preliminary study can provide references to the Taiwan government and other countries on the management for the air quality of workplaces.

Sampling Information
A decorating workplace in an apartment was selected in northern Taiwan.The apartment was 64 square meter on the fourth floor.The sampling location was shown in Fig. 1.The CO, CO 2 , temperature, and relative humidity were monitored for 5 minutes by an AirBoxx monitoring system (KD Engineering, USA), marked by sample A1-A6.Airboxx recorded data every 15 seconds.The level of HCHO was monitored for 5 minutes by a Formaldemeter htv monitoring system (PPM, United Kingdom), also marked by sample A1-A6.Formaldemeter recorded data every 50 seconds.(stage 5), and 0.65-1.1 µm (stage 6).The sampling flow rate was 28.3 L/min, the sampling time was 5 minutes, and the sampling height was approximately 150 cm.Two personal particle samplers PEM was located on the living room and study room, marked by sample P1-P2 and the sampling time was 24 hours.Sampling was undertaken during the decorating engineering including the dismantling old decorating, water and electrical pipe engineering, tiling engineering, window installation, pre-system furniture installation, flooring engineering, post-system furniture installation and finishing engineering.The windows were always open during all decorating engineering.Airboxx and HCHO sampler were set in the living room, corridor, guest room, study room, bedroom and back porch.Microbial cascade impactors were set in the living room, study room and back porch.As PEM sampler was set in the living room and study room.The sampling location was showed in Fig. 1.The diagram of the apartment is the as-built drawing.

Measurement and Analysis
Trypticase soy agar (TSA) with cycloheximide and malt extract agar (MEA) with chloramphenicol were used for capturing bacteria and fungi samples, respectively.Field blanks were also tested during the sampling.After sampling, the Petri dishes were incubated for 48 hrs at 37°C (Taiwan EPA method E301.11C) for bacteria and 120 hrs at 25°C (Taiwan EPA method E401.11C) for fungi.The concentrations of airborne bacteria and fungi (CFU/m 3 ) were calculated by dividing the total colonies counts on agar plate by air volume.The fractions for each stage of bacteria and fungi were defined as follows: B: bacterial fraction (%) C i : the i stage concentration for bacteria, which is 1 for the first stage (> 7 µm), 2 for the second stage (4.7-7 µm), 3 for the third stage (3.3-4.7 µm), 4 for the fourth stage (2.1-3.3 µm), 5 for the fifth stage (1.1-2.1 µm), and 6 for the sixth stage (0.65-1.1 µm) C b : total concentration of bacteria F: Fungal fraction (%) C i : the i stage concentration for fungi C f : total concentration of fungi (Kim and Kim, 2007) (3)

Data Analysis
This study uses SPSS 13.0 to calculate the descriptive statistics and the spearman's rank correlation test.It is a nonparametric measure of statistical dependence between the indoor air pollutants pairs.The test assesses how well the relationship between the indoor air pollutants pairs can be described using a monotonic function.

Level of CO and CO 2 Concentration
The individual CO 2 concentration ranged from 334 to 711 ppm during the decorating engineering.The averaged CO 2 concentration for various engineering was between 378 and 586 ppm, happening in the windows installation and finishing engineering, respectively (Table 1).The variation of  1), happening in the dismantling old decorating and water and electrical pipe engineering, respectively.The variation of CO concentration in various location for the same decorating engineering was more obvious than CO 2 concentration.The RSD ranged from 13.4% to 74.3%.The highest variation of CO concentration also occurred in the water and electrical pipe engineering.The higher variation for CO concentration possibly because the drill was rotated on the ground of living room during sampling, leading friction and heat loss between drill and cement.That probably resulted in the high CO concentration in the living room and hallway.
Fig. 2 showed the CO 2 to CO ratio during decorating engineering.Because the CO 2 concentration variation was not obvious, the CO concentration was lowest for dismantling old decorating.The CO 2 to CO ratio was consistent for tiling engineering and window installation, which was much simpler relative to other engineerings.

Level of HCHO Concentration
The individual HCHO concentration ranged from 0.05 to 1.3 ppm during the decorating engineering.The averaged HCHO concentration for various engineering was between 0.08 and 0.69 ppm (Table 1), happening in the flooring engineering and post-system furniture installation, respectively.The variation of HCHO concentration in various location for the same decorating engineering was apparent.
The RSD ranged from 18.6% to 84.3%.The highest variation of HCHO concentration occurred in the post-system furniture installation.There are three peaks for HCHO concentration during decorating engineering, including the tiling engineering, pre-system furniture installation and postsystem furniture installation (Fig. 3).The system furniture was set most in the living room and kitchen, partly in the guest room and study room (Fig. 1).After the system furnitures settled, the HCHO concentration increased apparently and lasted to the finishing engineering (the duration of sampling was 15 days).Lin (2010) measured HCHO concentration before and after a new decorating apartment.The result showed the HCHO concentration before and after decoration was 0.03 ppm and 0.05 ppm, separately.However, the HCHO concentration of an old house increased to 0.09 ppm.In this study, the high HCHO concentration for tiling engineering should be paid more attention.It was probably due to the tile adhesive emission, which needs further investigation in the future.
The individual temperature ranged from 25.0 to 32.4°C during the decorating engineering.The average temperature for various engineering was between 25.3 and 32.0°C (Table 1), happening in the flooring engineering and tiling engineering, respectively.The variation of temperature in various location for the same decorating engineering was so little.The RSD are all less than 2.0%.The situation was similar for the relative humidity.The individual relative humidity ranged from 54.9% to 80.6% during the decorating engineering.The averaged relative humidity for various engineering was between 61.1% and 79.9%, happening in the post-system furniture installation and finishing engineering, respectively.The variation of relative humidity in various location for the same decorating engineering was not obvious.The RSD are all less than 10.0%.The variation of  temperature and relative humidity were related with the sampling month, which was from August to October (Summer to Autumn).

Level of PM Concentration
The PM samples were taken for 24 hours.The sampling locations were chosen in the study room and living room owing to the limited samplers.The individual PM 2.5 concentration ranged from 48.6 to 1,201 µg/m 3 for the study room and 146 to 12,778 µg/m 3 for the living room, during the decorating engineering, respectively (Fig. 4(a)).The individual PM 10 concentration ranged from 69.4 to 2,722 µg/m 3 for the study room and 188 to 13,264 µg/m 3 for the living room, respectively (Fig. 4(b)).The ratio of PM 2.5 to PM 10 concentration ranged from 0.17 to 0.70 for the study room and 0.26 to 0.99 for the living room, respectively (Fig. 4

(c)).
There is no standard for PM 2.5 or PM 10 concentration for the working place in Taiwan, but the recommended exposure limit (REL) of respirable particles is 5 mg/m 3 .The PM 2.5 and PM 10 concentration of the tiling engineering was 12,778 and 13,264 ug/m 3 , which was more than two times of the REL.The highest PM concentration occurred during the water and electrical pipe engineering, which used the drillto  bore the holes on the ground.This led to lots of particles suspended in the air.The working environment for the decorating labor warrants further investigation in the future.

Level of Bioaerosol Concentration
Bacteria and Fungi samples were taken only in the living room and study room for the limited samplers.The bacterial concentration for living room ranged from 71 to 1731 CFU/m 3 .The highest bacterial concentration happened in the water and electrical pipe engineering.The bacterial concentration for study room ranged from 85 to 855 CFU/m 3 .The highest bacterial concentration also happened in the water and electrical pipe engineering (Fig. 5).The distribution of the bacterial concentrations for the living room and study room was similar, which probably indicated that the similar source during the engineering (Fig. 5).There were always four labors working during the decorating engineering.The relative high bacterial concentration occurred in the water and electrical pipe engineering, tiling engineering and flooring engineering, which contributed to more PM agitation during the engineering.
The fungal concentration for living room ranged from 134 to 1,463 CFU/m 3 .The highest bacterial concentration happened in the window installation.The fungal concentration for study room ranged from 170 to 898 CFU/m 3 .The highest fungal concentration also happened in the window installation.The distribution of the fungal concentrations for the living room and study room was similar (Fig. 6), however, not similar with the distribution of bacterial concentrations.This indicated that the different source for  bacteria and fungi during the engineering.The results showed that the fungal concentration was more relative to outdoors environment.
The B1-B6/F1-F6 pattern of the mean fractions of airborne bacteria/fungi for living room and study room were very different (Figs.7(a)-7(d)).The results were different with other studies processing in indoors (Lee and Kuo, 1993;Lin and Li, 1996).It indicated the unpredictable and variable airborne bacterial and fungal concentrations during the decorating engineering.Fig. 8 showed the mean respirable fractions, R b and R f , for bacteria and fungi, respectively.R b for living room and study room ranged from 27.8%-97.0%and 40.0%-83.9%,respectively.R f for living room and study room ranged from 29.4%-93.8%and 74.2%-83.2%,respectively.It should be noticeable that over 75% of R b and R f were higher than 50% during the decorating engineering both in the living room or the study room.The respirable fraction represents the fraction of bioaerosol easily penetrating into human trachea and bronchiole.The higher respirable fraction possibly implied the adverse health effect, such as asthma or allergy, would happen on those sensitive labors.Comparing with Kims' study (Kim and Kim, 2007), R b and R f ranged from 32.0-38.1% and 58.9-69.1%, the higher respirable fraction in the decorating engineering implies a higher adverse health risk for sensitive workers, and warrants further investigation.

Associations among Pollutants and Environmental Parameters
Table 2 listed the result of spearman's rank correlation test.There exited positive relationships for the following pairs: HCHO and CO, HCHO and CO 2 , CO and temperature, CO and bacterial concentration, PM 2.5 and PM 10 , the humidity and fungal concentration.Additionally, the negative relationships were found for the following pairs: CO and fungal concentration, PM 2.5 and fungal concentration, PM 10 and fungal concentration, the humidity and PM 10 .The positive correlation coefficients of PM 2.5 and PM 10 was the highest, 0.844 (p < 0.001).The negative correlation coefficients of PM 10 and fungal concentration was the highest, -0.762 (p < 0.001).It indicated no matter the various engineering process, the PM 2.5 concentration could possibly be closely predicted from the PM 10 concentration during the decorating engineering.The exposure risk assessment could probably be evaluated based on the limited information.

CONCLUSION
The studies related with measurements of air quality during decorating engineering were limited.This preliminary study will provide references for further exposure risk assessment.The CO concentration was very high for the drill rotating on the ground in the water and electrical pipe engineering.Additionally, the system furnitures installation contributed lots of HCHO in the workplace.The high PM 2.5 and PM 10 concentration for the tiling engineering was more than two times of REL.The exposure risk assessment of the working environment for the decorating labors warrants further investigation in the future.

Fig. 2 .
Fig. 2. The CO to CO 2 ratio during the decorating engineering.

Fig. 7 .
Fig. 7.The (a) bacterial fractions for living room (b) bacterial fractions for study rooms (c) fungal fractions for living room (d) fungal fractions for study rooms during the decorating engineering.

Fig. 8 .
Fig. 8.The respirable fractions of bioaerosols during the decorating engineering.

Table 2 .
Spearman's rho coefficient for indoor air pollutants.