**4.4 Health risk assessment and chemical risk prevention**

*Solvents, Ionic Liquids and Solvent Effects*

women.

on 0.4 mg/m3

TRV (0.04 mg/m3

**4.3 Carcinogenic effects**

based on a lifetime exposure.

(μg.m<sup>−</sup><sup>3</sup>

 (μg/m3 ) −1

the exposure concentration, is equal to 17.5 10<sup>−</sup><sup>2</sup>

for an occupationally exposed population.

specifically the renal cell carcinoma [33].

) −1

and is equal to 10<sup>−</sup><sup>6</sup>

and equal to 4.1 10<sup>−</sup><sup>6</sup>

cancer to humans.

6.3 × 10<sup>−</sup><sup>3</sup>

chronic Reference concentration (RfC) is fixed on 2 10<sup>−</sup><sup>3</sup>

but with great significance and likely adverse consequences.

developmental and immune effects. The mean value of all TCE concentrations is 21,385 times the RfC, which means that there is also an enormous risk related to the increase of congenital cardiac malformations and a decrease of thymus weight [36]. This developmental effect could be also alarming because 70% of the workers are

Regarding PCE, the chronic French TRV via inhalation is developed based on neurological effects. Among them, the ANSES distinguished the visual alterations as the most sensitive effect toward the lowest exposure levels [30]. The TRV is fixed

tions. Since the PCE concentration distribution is highly dispersed, the ratio, and consequently the risk, is even higher (108 times) if we use the upper bound of the 95% confidence interval for mean. As for the RfC, it is set at the tenth of the French

effects and color vision impairment induced by neurotoxicity [29]. Thus, the risk of neurotoxicity could be even 10 times higher for workers. It is worth to note that these risks maybe also extrapolated to the general population with lower intensity,

Chronic exposure can also induce carcinogenic effects. Thus, there are nonthreshold TRVs as well. Each value is established for a specific tumor site or sites

As shown in **Table 1**, according to World Health Organization (WHO) [13, 38], TCE was proved to cause kidney cancer to humans. Indeed, the French carcinogen TRV via inhalation, established by ANSES, is the ERU "excès de risque unitaire,"

Yet, other solid scientific evidences indicate other potential carcinogenic effects of TCE. In fact, the US EPA established the Inhalation Unit Risk for three different cancer sites: the hematologic, liver, and kidney cancers. Its value is more protective

cancer risk, which is defined as the product of multiplying the carcinogen TRV by

value of all TCE concentrations. This means that, more than 17 additional cases of hematologic, hepatic, and renal cancers are estimated to occur during a lifetime exposure to TCE in a population of 100 people. This value is considerably high even

Furthermore, other international agencies have also demonstrated the carcino-

As for PCE, according to WHO [38], it is probably inducing urinary bladder

Elsewhere, ERU established by ANSES is based on liver cancer (hepatocel-

Additionally, the Inhalation Unit Risk by US EPA has the same value, but only for the hepatic cancer. According to this carcinogen TRV, the lifetime cancer risk is

place during a lifetime exposure in a population of 1000 people. Due to the high variability of PCE concentrations, this value could be even higher (more than 11 cases if the upper bound of the 95% confidence interval for mean is used) in some cases. Although these findings are slightly better than those for the TCE, they are still high and troubling. In fact, the inhalation cancer risk could be worse

. It means that six additional cases of liver cancer are expected to take

genic effect of TCE for other target organs, such as in testes or in lungs [33].

lular adenoma and carcinoma) [30] and is equal to 2.6 × 10<sup>−</sup><sup>7</sup>

[30, 32], which is over 60 times the mean value of all PCE concentra-

[37]) based also on neurological effects, notably neurobehavioral

[32]. It was constructed based on kidney cancer,

[35, 36]. According to the latter value, the lifetime

, when compared with the mean

 (μg/m3 ) −1 [32].

mg/m3

[35] based on both

**36**

In Tunisia, chemical risk assessment studies have started in many industrial sectors that are handling solvents, such as adhesive [39] and shoe manufacturing [40] industries. Yet, the occupational exposure in dry cleaning industry is not explored. The exposure assessment was achieved using questionnaires and indoor air measurements. In fact, air samplings were carried out for the first time in the region of Sfax. We consider that this study will help for better understanding the dry cleaning industrial sector in Tunisia, which will lead to further improvement in health risk assessment studies in this sector.

All the 33 dry cleaning facilities in Sfax have announced to use PCE as a dry cleaning product; however, due to the high TCE concentrations, we assume the following:


It is worth to note that in our study, the air monitoring was conducted during the warm season (in June and the temperature was ~30°C) when the workplaces were relatively highly ventilated; doors and windows were open. However, in winter season, they are rather closed. So, we suppose that the exposure levels will be even higher in poor ventilation conditions.

The suggested corrective measures could start with the substitution. It consists of eliminating the use of the hazardous products by replacing them with less dangerous ones, especially because they are suspected to contain a high amount of TCE or by switching to a different process. Among the substitution processes, there are the (i) wet cleaning that consists of using a mixture of water, detergents, and surfactants whose risks are little or currently unknown, (ii) hydrocarbon dry cleaning that involves solvents that are less volatile than PCE, and (iii) siloxane D5 dry cleaning that are using the latter product as a liquid solvent that is barely volatile. These alternative machines may be quite costly; however, other easier corrective actions could be carried out.

For the second level of the corrective actions, we highly recommend the implementation of collective protection measures (CPM). In every facility, general mechanical ventilation ought to be installed immediately, with fume extraction systems positioned toward every job task. It should be noted that the polluted air needs to be rejected after purification [7]. In addition, the mechanical ventilation has to be supplied by outdoor fresh air and the reuse of the same air after gas scrubbing is interdicted [7].

The third level of the corrective actions involves the mandatory use of PPE in some job tasks. The wearing of protective clothing is advisable for every worker. Elsewhere, we noticed that the loading of solvents in the cleaning machines is generally introduced by manual pouring on the back or through the porthole,

which increases the risk of exposure by direct contact with solvents. Thus, in such job tasks where workers are directly handling solvents for short duration, the use of gloves, safety glasses, and appropriate respiratory protective device is compulsory. The used gloves have to be made of polyvinyl alcohol or Viton® or Téflon® [25, 26]. Latex, butyl rubber, and polyethylene gloves are not suitable to be used for PCE [26]. The respiratory equipment should be equipped with gas filter type A [25, 26].
