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Background: Hazardous Materials and Chemical/Biological/Radiological/Nuclear (HazMat-CBRN) incidents represent a serious threat to the population and the environment1. They require a pre-hospital medical response system well equipped and supported with logistics and clinicians with appropriate knowledge and skills to prevent exposure and mitigate risks. Our aim is to determine if the Hamad Medical Corporation Ambulance Service (HMCAS) fulfils the pre-hospital readiness requirements for such incidents. Methods: This cross-sectional study was performed in HMCAS. An online survey assessed staff behaviour and knowledge in relation to HazMat-CBRN incidents. Responses were obtained on health risks and pre-hospital medical management of related threats in Qatar. Based on the results, a training module “HazMat Incident Management” was prepared with pre-/post-activity assessments. The results were explored using a multivariate linear regression and non-parametric Wilcoxon test for paired samples. Specialized Emergency Management (SEM) staff opinion about this training was assessed through an online survey. Both surveys’ validity and reliability tests were conducted. Ishikawa cause and effects diagram was built for the identification of the factors leading to a pre-hospital successful response to HazMat-CBRN incidents. Results: HMCAS has the proper logistics and plans to manage potential HazMat-CBRN incidents. The knowledge survey demonstrated that the pre-hospital medical staff information about this topic needs reinforcement. The multivariate linear regression (Table 1)and non-parametric Wilcoxon test (Table 2) demonstrated that this was obtained thanks to the implemented training module. The course satisfaction survey showed not only a big interest in this activity but also staff recommended more related topics2. Earlier-RSDAT (Recognition, Safety, Decontamination, Antidot, Transport) is a tool proposed as a response acronym to build a successful risk-based response for HazMat CBRN incidents in pre-hospital setting3. Conclusion: HMCAS fulfills the readiness requirements for safe and effective response to potential HazMat-CBRN incidents in Qatar. The RSDAT response matrix might help in mitigating pre-hospital response risks.

The use of chlorinated solvents in dry cleaning poses risks to human health. The current study is the first in Tunisia and Sfax city that aims to assess the occupational exposure and health risks of perchloroethylene (PCE) and trichloroethylene (TCE) in the dry cleaning industry. Forty-seven dry cleaning facilities were identified by door-to-door canvassing within a 5 km radius from the city centre, but only 33 accepted to join this study. The exposure assessment was conducted by indoor air measurements for 16 randomly selected facilities. The exposure levels were compared to occupational exposure limit values (OELV). Hazard quotient (HQ) method was used and cancer risks were evaluated. Hazard quotients for both solvents are enormously above 1, with an order of magnitude equal or higher than 103. Corresponding risks are developmental and immune effects for TCE and neurotoxicity for PCE. These results showed that inhalation exposure levels might induce many adverse effects that are probably threatening the occupationally exposed population and even the general one, because of the location of all facilities in residential settings. As for carcinogenic effects, high kidney, hematologic or liver cancer risks were noticed if the lifetime exposure would have these average levels. This study is significant for a better understanding of the dry cleaning industrial sector in Tunisia. Indeed, it responded to many interrogations and suspicions about the qualitative and quantitative exposure conditions, and thus the health status of dry cleaning workers in Sfax.

The use of chlorinated solvents in dry cleaning poses risks to human health. The current study is the first in Tunisia and Sfax city that aims to assess the occupational exposure and health risks of perchloroethylene (PCE) and trichloroethylene (TCE) in the dry cleaning industry. TCE was suspected to be used as it is not explicitly banned by law. We identified dry cleaning facilities by door-to-door canvassing within a 5 Km radius from the city center of Sfax. We found 47 facilities, but only 33 accepted to join our study. Then, we randomly selected 16 facilities where the exposure assessment to these solvents was conducted by indoor air measurements. The exposure levels were compared to occupational exposure limit values (OELV) and toxicological reference values. Then, cancer risks were evaluated. TCE was detected in all workplaces and their levels are close to the OELV (95% CI of the mean value [40.4-46 mg/m3]). The mean value of PCE concentrations is lower than the fifth of the OELV, but they are quite variable (95% CI of the mean value [5.1-43.4 mg/m3]). The overall results showed that inhalation exposure levels may induce many adverse effects that are probably threatening the occupationally exposed population and even the general one, because of the location of all facilities in residential settings. Among threshold effects, we noted high risks of neurological, renal, developmental and immune effects. As for carcinogenic effects, greatly high cancer risks were noticed if the lifetime exposure would have these average levels; 17 additional cases of kidney, hematologic or liver cancers are expected to occur in populations of 100. This study is significant for better understanding of the dry cleaning industrial sector in Tunisia and for the progress of future risk assessment studies. Indeed, it responded to many interrogations and suspicions about the qualitative and quantitative exposure conditions and thus the health status of dry cleaning workers in Sfax. Key messages Our study is the first health risk assessment study of the exposure to chlorinated solvents in dry cleaning in Sfax city. It revealed high levels of trichloroethylene that is a carcinogen to humans. The high exposure levels to per and tri-chloroethylene, in dry cleaning in Sfax city, may induce adverse health effects to workers and even the general population due to residential exposure.

Mathematical models for estimating occupational exposure to chemicals were developed as a promising alternative to air monitoring that is pricey and sometimes unavailable. Still, models parameters are derived from former air monitoring. Contrarily, our study aims to calculate all parameters independently of monitoring data. We implemented this approach to assess exposure in welding plants. Then, prediction abilities are evaluated by comparison with air measurements. The Near Field-Far Field (NF-FF) model seeks to give accurate exposure estimation near an emission source. One workplace includes Shielded Metal Arc Welding (SMAW) worker T1 who is in the NF. The other contains induction welding (IW) T2 and packaging workers T3 who are in NF and FF, respectively. The emitted metals are identified from materials compositions. Ventilation rates are calculated by the anemometer technique. Emission rates are calculated using the emission factor method for SMAW and mass balance method for IW, solely based on literature, materials quantities and their compositions. To evaluate the match between measured (6 replicates) and predicted levels, we checked their correlations and tested the mean differences of paired values. T1 is exposed to Al, Cu, Ni, Cr and Pb, while T2 and T3 are exposed to Al, Cu, Ni, Cr and Zn. A strong correlation was found (r = 0.78, p = 0.008) for NF predictions and air measurements. The T-test was significant, confirming that NF predictions and measured levels are quite close. In contrast, our approach did not succeed to predict the FF exposure (insignificant correlation), which is probably due to the mobility of T3. Non-air monitoring based models showed good effectiveness to predict the exposure levels close to emission sources for SMAW and IW processes. Thus, to assess health risks or to evaluate compliance with workplace air standards, our modeling approach that is time and cost saving, can be adopted as a support tool or even an alternative to air monitoring. Key messages With a view to assess occupational exposure, non-air monitoring based models, that are time and cost saving tools, showed good prediction abilities for trace metal levels near welding emission sources. The use of non-air monitoring based models would help to control the working environment of occupationally exposed populations to welding fumes, which is useful to comply with air quality standards.

International audience; Background - Sfax is a very industrialized city located in the southern region of Tunisia where heavy metals (HMs) pollution is now an established matter of fact. The health of its residents mainly those engaged in industrial metals-based activities is under threat. Indeed, such workers are being exposed to a variety of HMs mixtures, and this exposure has cumulative properties. Whereas current HMs exposure assessment is mainly carried out using direct air monitoring approaches, the present study aims to assess health risks associated with chronic occupational exposure to HMs in industry, using a modeling approach that will be validated later on.Methods - To this end, two questionnaires were used. The first was an identification/descriptive questionnaire aimed at identifying, for each company: the specific activities, materials used, manufactured products and number of employees exposed. The second related to the job-task of the exposed persons, workplace characteristics (dimensions, ventilation, etc.), type of metals and emission configuration in space and time. Indoor air HMs concentrations were predicted, based on the mathematical models generally used to estimate occupational exposure to volatile substances (such as solvents). Later on, and in order to validate the adopted model, air monitoring will be carried out, as well as some biological monitoring aimed at assessing HMs excretion in the urine of workers volunteering to participate. Lastly, an interaction-based hazard index HI and a decision support tool will be used to predict the cumulative risk assessment for HMs mixtures.Discussion - One hundred sixty-one persons working in the 5 participating companies have been identified. Of these, 110 are directly engaged with HMs in the course of the manufacturing process. This model-based prediction of occupational exposure represents an alternative tool that is both time-saving and cost-effective in comparison with direct air monitoring approaches. Following validation of the different models according to job processes, via comparison with direct measurements and exploration of correlations with biological monitoring, these estimates will allow a cumulative risk characterization.

Hydro-(major and trace elements: Cd, F and Sr), isotope (18O, 2H, 3H and 13C) geochemistry and radiogenic carbon (14C) of dissolved inorganic carbon (DIC) were used to investigate the sources of groundwater contamination and the hydrodynamic functioning of the multilayer aquifer system in the mining Gafsa basin (Southwestern Tunisia). The groundwater of the study area is subject to intense exploitation to accommodate all the water demands of this arid area. The Gafsa basin contains a multi-layered aquifer with four principal levels: Upper Zebbag (Cenomanian–Turonian), Abiod (Campanien–Maastrichian), Beglia (Miocene) and Segui (Plio–Quaternary) Formations. The hydrogeology of this system is largely affected by tectonics (Gafsa–Tebessa, Sehib, Negrine–Tozeur, Tabeddit and Metlaoui faults…). The groundwater of these aquifers undergoes a significant decline in water level (≈0.5 m y−1), increasing salinity (TDS increase from 400 to 800–6000 mg l−1: generally, TDS increases from the mountainous regions towards the discharge area) due to a long time of aridity, irregular rainfall and overexploitation (irrigation and industrial activities). Groundwater pumped from the semi-confined Complex Terminal (C.T) aquifers (Cretaceous and Mio-Plio-Quaternary: MPQ) and from the confined Continental Intercalaire (C.I) aquifers is an important production factor in irrigated oases agriculture and phosphate washing in Southwestern Tunisia. A rise in the groundwater salinity has been observed as a consequence of increasing abstraction from the aquifer during the last few decades. The salinization phenomena in the region are complex. Several possible causes for salinization exist: (1) the upwelling of saline and “fossil” water from the underlying, confined “C.I” aquifer; (2) as well as the backflow of agricultural drainage water; (3) phosphate and domestic wastewater; (4) brine intrusion from the salt lake (Sebkha/Garaat); (5) evaporate meteoric water dams (El Khangua and El Oudei); (6) reduced rainfall and (7) land and air alterations. The istopic study of waters establishes that the deep groundwater is “fossil” water (6000–37,000 years) recharged probably during the late Pleistocene and the early Holocene periods. The relatively recent water in the MPQ aquifer is composed of mixed waters resulting presumably from upward leakage from the deeper groundwater.

Objectif Malgre l’importance de l’utilisation des solvants organiques dans l’industrie de chaussures, les donnees d’exposition des salaries a ces solvants dans ce secteur sont quasi-absentes en Tunisie. Le but de cette etude est de mettre au point des protocoles d’analyse toxicologique de melanges de solvants afin d’instaurer une surveillance bio-toxicologique d’exposition dans l’industrie de chaussures. Methodes Apres recensement des solvants les plus predominants dans les preparations utilisees dans la fabrication de chaussures (acetone, cyclohexane, hexane, methylethylcetone, toluene), 18 entreprises volontaires subdivisees en 3 groupes selon le procede de fabrication (4 industrielles, 5 semi-industrielles et 9 artisanales) ont beneficie de 55 prelevements atmospheriques dynamiques (33 individuels et 22 a poste fixe) sur une duree de 4 h. Un echantillon urinaire de fin de poste – fin de semaine a ete preleve chez 185 travailleurs de ces entreprises (105 industriels, 60 semi-industriels et 25 artisanaux) afin de doser les solvants selectionnes et leurs metabolites. Resultats Le dosage des solvants cibles dans l’atmosphere a ete realise par la CPG selon les conditions operatoires prealablement optimisees. Le dosage des solvants cibles et metabolites dans les urines a ete fait par CPG pour l’acetone, le 2,5-Hexanedione, la methyl-ethyl-cetone, le 1,2 et le 1,4-cyclohexanediol et par HPLC pour l’acide hippurique et l’acide Trans,trans-muconique. Concernant les concentrations atmospheriques, l’indice toxicologique du melange (∑[Concentration/VLEP]) s’echelonnait entre 0,1 et 8,8 et presentait des valeurs moyennes superieures a 1, principalement dans le procede semi-industriel. Ces valeurs atteignaient respectivement 1,7 ; 2,5 et 4,5 pour les postes de finition, de tigeur et de fondeur. Les concentrations atmospheriques moyennes de certains solvants depassaient les VLEP pour l’hexane dont les valeurs atteignent dans certains postes 214 mg/m3 (VMEHexane = 72 mg/m3). Concernant le suivi biologique, les concentrations en acide hippurique [AH] depassaient la valeur limite biologique (VLBAH = 1600 mg/g creat) dans le procede semi-industriel pour les fondeurs et tigeurs avec des moyennes respectives [AH]Fondeurs = 2349,4 mg/g creatinine et [AH]Tigeurs = 3215,5 mg/g creatinine. Pour le toluene, l’absence de depassement de la VME, certains artisans au poste de « tigeur/fondeur » avaient des concentrations urinaires relativement elevees variant de 440,2 a 4784,5 mg/g creatinine avec une moyenne de 3292,5 mg/g creatinine. L’acide trans-muconique a ete mis en evidence dans les procedes industriel et artisanal avec des moyennes variant de 1,2 a 3,1 mg/g creat. Conclusion La CPG et la HPLC ont ete efficacement utilisees pour l’analyse de solvants organiques et de leurs metabolites. Le developpement de ces indicateurs a necessite l’utilisation de ces techniques pour la surveillance professionnelle pour la premiere fois dans la region [1] , [2] . Ainsi, une demarche d’evaluation du risque professionnel par la surveillance bio-toxicologique d’exposition est mise en place [1] .

Air quality transcends all scales with in the atmosphere from the local to the global with handovers and feedbacks at each scale interaction. Air quality has manifold effects on health, ecosystems, heritage and climate. New insights into the characterisation of both natural and anthropogenic emissions are reviewed looking at both natural (e.g. dust and lightning) as well as plant emissions. In the phosphate mining area (El Guettar–M’Dilla basin: Southwestern Tunisia), several diseases have been known as cancer, respiratory, allergies, cardiovascular, dental fluorosis, stress, etc. These diseases are directly related with the installation of the industrial sector of the CPG (from 1896) and the deforestation and the ecosystem degradation (fauna and flora).

High-level occupational exposure to volatile organic solvents may elicit neurotoxic effects, especially on central and peripheral structures involved in balance ability. Studies on balance control in relation with exposure levels close to the threshold limit values are scarce. This study aimed to assess the neurotoxic effects of chronic and subchronic exposure to organic solvents among workers in plant manufacturing adhesive materials. Balance control was evaluated in 18 subjects, mainly exposed to n-hexane and toluene, with current median exposure levels of 222 and 102 mg/m(3), respectively, and a median exposure duration of 21 years, and in 32 nonexposed controls, using posturography tests with and without sensory conflicting situations. Tests were undergone at the beginning of the work shift (chronic exposure) following a week end, and after 72 h (subchronic exposure). Balance control performance was lower in chronically exposed workers compared to controls, and got worse after subchronic exposure, particularly during situations, where vestibular information was important. Our study suggests that a low-level and prolonged exposure to volatile organic solvents, mainly n-hexane and toluene, in the workplace is associated with deleterious central effects involved in postural regulation. This neurotoxicity is characterized by difficulties to use the most relevant information to control balance, leading to altered management of sensory conflicting situations.

International audience

Objectives to assess environmental and biological monitoring of exposure to organic solvents in a glue-manufacturing company in Sfax, Tunisia. Methods Exposure of volunteer workers, in the solvented glue-work-stations, in the control laboratory and in the storage rooms of the finished products, was assessed through indoor-air and urine measurements. Informed consent of the workers was obtained. Results and discussion The exposure indexes were found with high values in the solvented workshop as well as in the control laboratory and were respectively, 8.40 and 3.12. These indexes were also correlated with hexane and toluene indoor air concentrations. As to urine, the obtained results for the 2,5-hexandione and hippuric acid, metabolites of hexane and toluene, respectively, were in accord with the indoor-air measurements, with an average of 0.46 mg/l and 1240 mg/g of creatinine. Conclusion This study assessed for the first time biological exposure to organic solvents used in Tunisian adhesive industries. Although values are likely to underestimate true exposure levels, some figures exceed European and American occupational exposure guidelines.