**3. Results**

*Solvents, Ionic Liquids and Solvent Effects*

**32**

**Table 2.**

**Figure 3.**

*from indoor air monitoring are encircled in red.*

*perchloroethylene.*

**2.5 Occupational exposure limit values**

column (DB-23) features are length = 60 m, inner diameter = 0.32 mm, and film thickness = 0.25 μm. The temperature of injection is 200°C and the oven program is the following: 35°C (3 min), 7.5°C/min, 115°C (0 min), 15°C/min, 200°C (2 min). The vector gas is nitrogen with a flow rate of 2 ml/min. We adopted external calibration using the same solvent as for the samples [19, 20, 23]. Then, the air concentrations of both solvents were calculated using the airflow rates and sampling durations [24].

*Occupational exposure limit values developed from different countries for trichloroethylene and* 

**OELV TCE PCE**

*Location of dry cleaning facilities in a radius of 5 km from the city center of Sfax. The facilities that profited* 

**(mg/m3**

France (INRS, ANSES) [17, 18, 25–27] 405 75 138 20 Europe (SCOEL) [17, 18, 27, 28] 55 10 138 20 USA (ACGIH) [25, 26] 55 10 170 25 Selected for this study 55 10 138 20

**Solvents**

**) (ppm)**

**) (ppm) (mg/m3**

The fixed amount on a sorbent tube over a work shift corresponds to average concentrations of solvents and subsequently will be compared with

Following the door-to-door canvassing, 47 dry cleaning facilities were located in the city of Sfax within a radius of 5 km. **Figure 3** shows the locations of facilities in each major road using the map of Sfax city from "Google Maps." The facilities' locations on the map show their congestion in the city center with 19 dry cleaners which represents more than 40%. No facility has been identified in the medina quarter or the Sidi Mansour road.

After the meetings with the facilities' managers, only 33 dry cleaning companies accepted to participate to our study. Thus, we had an agreement with them about the confidentiality of their names, contacts and any personal specific data. The identification questionnaire was carried out for all of them. Then, we randomly selected 16 facilities. The selected ones are highlighted on the map in **Figure 3**.

It was noticed that the majority of dry cleaning establishments are located next to habitation. Moreover, they are exclusively naturally ventilated through open doors/windows. The 33 explored facilities have small surfaces with a mean value of 31.3 m2 (95% CI [25.6-37]) where there are one or two machines. Despite all these exposure circumstances, we highlighted the almost total lack of personal protective equipment (PPE). In fact, employees never use masks even when they are directly manipulating the solvents, only one facility provides gloves, and three facilities use protective clothing.

The work activity is semiindustrial and the dry cleaners reported that they are solely using PCE with a mean quantity of 177.6 L/year (95% CI [159.9-195.3]). The number of workers in the facilities varied from 1 to 6, yet about 70% of them were women.

The chromatograms of our analysis show sharp, narrow, and well-separated peaks of both solvents. Interestingly, TCE is detected in all samples (fixed and personal), whereas the PCE is detected only in 6 workplaces among the 16 (**Table 3**).

TCE concentrations in the workplaces' atmospheres are almost equal in all facilities except for F3 (coefficient of variation (CV) is equal to 12.5%). In fact, their mean value is nearly the same as their median: ~43.2 mg/m3 (95% CI [40.4-46]). Only in F3, the TCE concentration in the workplace's atmosphere is 40% lower than the mean concentration in all facilities. This could be due to the large surface of F3 compared to the other workplaces, which is 43% higher than the mean surface value. Moreover, we noticed that dry cleaners in F3 are using the lowest quantity of solvents, which is 60% lower than the mean quantity used in all facilities.

As for PCE concentrations in the workplaces' atmospheres, they are remarkably variable with a CV higher than 100%, which is significantly higher than the CV of TCE concentrations in the workplaces' atmospheres. PCE concentrations in the workplaces' atmospheres have no relationship with the used quantity of solvents. This may be explained by the differences in the working behaviors between the facilities, since all of them are not following the same standard prevention measures.

As for the personal sampling, TCE concentrations are almost the same as the workplace atmosphere levels, except for F3 where it increased by about 25%. However,


#### **Table 3.**

*Indoor air measured concentrations of TCE and PCE in dry cleaning facilities.*

it still is 18% lower than the mean value of TCE concentrations in the workplaces' atmospheres, which confirms its connection with the lowest consumed quantity.

Regarding PCE, the personal sampling concentrations are higher than workplaces' atmospheres, particularly in P3 where the PCE level has doubled. Thus, the employees who are carrying personal sampling devices (particularly in F3 and F29) are exposed to greater levels of solvents. This is obviously due to their specific movement patterns where they could be moving closer to the emission sources. This consequently justifies our judgment to use the personal sampling in these job tasks.

As we can notice in **Table 3**, almost all TCE concentrations are close to the selected OELV (**Table 2**). These results are quite surprising because all facilities have declared to only use PCE. In fact, we suspected to have found TCE in trace amounts as impurity content. But, these high concentrations are an alarming finding. Thus, even though all PCE concentrations are lower than one-tenth of the OELV (except for both measurements in F29 and for F3 personal sampling level), we believe that urgent corrective actions should be carried out in all facilities.
