RESUMEN
Work-related musculoskeletal disorders (WRMSD) pose a significant occupational health challenge in Europe. The digitization of the economy substantially reshaped the nature and organization of work. The proliferation of hybrid working, characterized by a combination of office-based and remote work, has been accelerated by the COVID-19 pandemic. This review covers hybrid forms of work, their impact on WRMSDs, and the potential implications for WRMSD compensation. Approximately 30-40% of the European workforce could potentially transition to hybrid forms of work. Hybrid work arrangements can result in prolonged static postures of the trunk, neck, and upper limbs without adequate breaks, thereby increasing the risk of neck and lower back pain. As teleworking and hybrid working become more prevalent, an increase in non-specific WRMSDs is anticipated among the working population. In many countries, claims for WRMSDs necessitate a formal diagnosis by a healthcare professional. However, cases of non-specific WRMSDs, such as cervicalgia or chronic shoulder pain, - commonly observed in sedentary workers engaged in predominantly low-intensity, prolonged static work amid visually and cognitively demanding tasks - often do not meet the criteria for compensation as occupational diseases. The compensation system and/or the criteria for compensation must be adapted to accommodate the rise of telework, necessitating evolving criteria for compensation that address both medical and risk exposure considerations.
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COVID-19 , Enfermedades Musculoesqueléticas , Enfermedades Profesionales , Indemnización para Trabajadores , Humanos , Indemnización para Trabajadores/economía , Europa (Continente) , TeletrabajoRESUMEN
OBJECTIVES: Musculoskeletal disorders (MSDs) are a leading cause of disability and sick leave among workers. Although MSDs are associated with physical exposures, there are gender differences in the prevalence and related disability. This study aimed to compare self-reported physical work exposures by gender for people within the same occupational group. METHODS: We used cross-sectional data from 65 281 asymptomatic workers aged 18-69 years from the CONSTANCES cohort study (France). We compared 27 physical exposures between men and women in the same occupational groups ('Profession et Categorie Sociale' group) using Mann-Whitney U tests. RESULTS: Men and women performing the same job often reported different levels of exposure. 38 of 365 occupational groups had a gender difference in reported exposure for 10 or more of 27 physical exposures, with men reporting higher exposures in 79% of these jobs. Women reported higher exposures in nursing and other healthcare professions. The probability that a random man had an exposure value higher than a random woman varied widely, from 8% to 92%, and was highly dependent on occupational groups and the specific exposure. CONCLUSIONS: Men and women working in the same jobs reported different physical exposures for some jobs and some exposures. Further research should further define and explore these reported differences to improve prevention and research.
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Enfermedades Musculoesqueléticas , Enfermedades Profesionales , Exposición Profesional , Femenino , Humanos , Masculino , Estudios de Cohortes , Estudios Transversales , Francia/epidemiología , Enfermedades Musculoesqueléticas/epidemiología , Enfermedades Musculoesqueléticas/etiología , Enfermedades Profesionales/epidemiología , Enfermedades Profesionales/etiología , Exposición Profesional/efectos adversos , Ocupaciones , Factores de Riesgo , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , AncianoRESUMEN
BACKGROUND: Though there is increasing evidence on the effect of long working hours (LWH) and stroke, few studies have distinguished stroke subtypes. We examined the associations between LWH and ischaemic or haemorrhagic stroke after adjusting for cardiovascular risk factors. METHODS: From a national population-based cohort CONSTANCES, baseline questionnaires and initial health examinations were used to retrieve sociodemographic and cardiovascular risk factors from 2012 to 2018. LWH were defined as self-reported working time≥10 hours daily for at least 50 days per year. Incident cases of stroke were collected using International Classification of Disease codes recorded in the National Health Data System. Associations between LWH and stroke were investigated using multinomial models adjusted for cardiovascular risk factors. RESULTS: Among the 160 751 participants who were free from stroke at baseline, exposure to LWH≥10 years was reported by 20 723 participants, and 190 incident cases of stroke were identified, including 134 ischaemic and 56 haemorrhagic. Exposure to LWH was associated with an elevated odds of ischaemic stroke (OR=1.61 (1.04-2.49)) and haemorrhagic stroke (OR=2.50 (1.38-4.53)) in unadjusted models. In adjusted multivariable models, only the LWH association with haemorrhagic stroke remained significant (aOR=1.92 (1.01-3.09)). CONCLUSIONS: LWH were associated with stroke, though it remained significant for haemorrhagic stroke only after adjustments. Differences in direct and indirect biological pathways and lack of power in the ischaemic subgroup may explain these results and further studies on the impact of mediating and effect measure modifying factors are needed. Nevertheless, policies that attenuate effects of both LWH and cardiovascular risks factor are warranted.
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Isquemia Encefálica , Accidente Cerebrovascular Hemorrágico , Accidente Cerebrovascular , Humanos , Accidente Cerebrovascular/epidemiología , Accidente Cerebrovascular/etiología , Isquemia Encefálica/epidemiología , Isquemia Encefálica/complicaciones , Factores de Riesgo , Accidente Cerebrovascular Hemorrágico/complicacionesRESUMEN
Source contributions to PM2.5 concentrations were evaluated in Greater Beirut (Lebanon), a typical East Mediterranean-Middle East (EMME) city, using Positive Matrix Factorization with two approaches. The first approach included only inorganic species (PMF-trad) and the other approach added organic markers (PMF-org). PMF-org identified 4 additional sources, and large discrepancies in contributions were observed for some major sources found in both approaches, highlighting the importance of including organic markers. The traffic factor was underestimated in PMF-trad by 2 to 7 folds. Moreover, results showed that this city is prone to high desert dust concentrations originating from uncontrollable dust storm events, like all cities in the Middle East. A PM2.5 mitigation plan taking into account the potency of the identified sources was developed. Sources like diesel generators or traffic presented smaller contributions in term of mass compared to desert dust, however the health impact of the latter is relatively small and actions should target sources with the highest potency. Local emission inventories in the EMME region are scarce and studies typically rely on global emission inventories for local air quality management plans, but these inventories significantly underestimate Beirut's road transport emissions by more than an order of magnitude.
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Contaminantes Atmosféricos , Contaminantes Atmosféricos/análisis , Material Particulado/análisis , Ciudades , Emisiones de Vehículos/análisis , Monitoreo del Ambiente/métodos , Polvo/análisis , Medio Oriente , Estaciones del AñoRESUMEN
PURPOSE: Machine learning (ML) methods showed a higher accuracy in identifying individuals without cancer who were unable to return to work (RTW) compared to the classical methods (e.g. logistic regression models). We therefore aim to discuss the value of these methods in relation to RTW for cancer survivors. METHODS: Breast cancer (BC) survivors who were working at diagnosis within the CONSTANCES cohort were included in the study. RTW was assessed five years after the BC diagnosis (early retirement was considered as non-RTW). Age and occupation at diagnosis, and physical occupational job exposures assessed using the Job Exposure Matrix, JEM-CONSTANCES, were evaluated as predictors of RTW five years after BC diagnosis. The following four ML methods were used: (i) k-nearest neighbors; (ii) random forest; (iii) neural network; and (iv) elastic net. RESULTS: The training sample included 683 BC survivors (RTW: 85.7%), and the test sample 171 (RTW: 85.4%). The elastic net method had the best results despite low sensitivity (accuracy = 76.6%; sensitivity = 31.7%; specificity = 90.8%), and the random forest model was the most accurate (= 79.5%) but also the least sensitive (= 14.3%). CONCLUSION: This study takes a first step towards opening up new possibilities for identifying the occupational determinants of cancer survivors' RTW. Further work, including a larger sample size, and more predictor variables, is now needed.
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Neoplasias de la Mama , Supervivientes de Cáncer , Humanos , Femenino , Reinserción al Trabajo , Sobrevivientes , OcupacionesRESUMEN
PURPOSE: Musculoskeletal disorders (MSDs) are common worldwide and gender differences exist in terms of prevalence and disability. MSDs are a leading cause of sick leave and physical work exposures. To assess the association between physical exposures assessed by the gender-specific CONSTANCES Job-Exposure Matrix (JEM) and musculoskeletal pain in six areas: neck pain, shoulder pain, elbow/arm pain, hand/wrist pain, low back pain, knee/leg pain; and to compare the results with those obtained using the non-gendered CONSTANCES JEM and with individual self-report exposures. METHODS: We included 48,736 male and 63,326 female workers from the CONSTANCES cohort (France). The association between 27 physical exposures and musculoskeletal self-reported pain in six body areas was assessed using logistic regression. We conducted the analysis with three types of exposures: (1) individual self-reported exposures; (2) gender-specific CONSTANCES JEM; (3) non-gendered CONSTANCES JEM, and adjusted for age and Body Mass Index (BMI). Analyses were stratified by gender. RESULTS: The associations to the gender-specific and non-gendered JEM were similar. The odds ratios using individual self-reported exposures were comparable to the JEM-based associations, with the exceptions of the exposures 'change tasks', 'rest eyes' and 'reach behind'. In some comparisons, there were differences in the direction and/or significance of effects between genders (regardless of whether the JEM used was gender-specific or not). CONCLUSION: The gender-specific and non-gendered JEMs gave similar results, hence, developing physical work exposures JEMs that are gender-specific may not be essential. However, when predicting musculoskeletal pain, it seems relevant to stratify the analysis by gender.
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The chemical composition of PM2.5 at two sites in Lebanon, a country in the East Mediterranean - Middle East region, is investigated in the spring and summer seasons. The average PM2.5 concentrations were of (29 ± 16) µg/m3 for Beirut urban site and (32 ± 14) µg/m3 for Beirut suburban site. This study showed that the geographic location of the East Mediterranean region, such as its proximity to the Mediterranean Sea and the dust storm intrusion are a significant contributor to the high PM levels from natural sources, which cannot be mitigated, rendering the PM2.5 WHO annual Air Quality guideline unattainable due to high natural background, which also applies to the entire Middle East region. Turkey and Eastern Europe are the dominant origin of air masses throughout our sampling days, suggesting the long-range transport as an important potential contributor to the high observed concentrations of V, Ni, and sulfate in this region most probably in other East Mediterranean countries than Lebanon too. Main local sources determined through the chemical speciation including organics are road transport, resuspension of dust and diesel private generators. A health risk assessment of airborne metals was performed and the carcinogenic risk for all the metals exceeded by 42 (adults) and 14 (children) times the acceptable risk level (10-6) at both sites. Vanadium was the predominant carcinogenic metal, emphasizing the need to replace energy production with cleaner energy on a regional level and highlighting the severe impact of air pollution on the health of inhabitants in this region's main cities.
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Contaminantes Atmosféricos , Adulto , Niño , Humanos , Contaminantes Atmosféricos/análisis , Ciudades , Emisiones de Vehículos/análisis , Líbano , Monitoreo del Ambiente , Polvo/análisis , Estaciones del Año , Material Particulado/análisisRESUMEN
OBJECTIVES: The COVID-19 pandemic has brought to light a new occupational health threat. We aimed to evaluate the association between COVID-19 infection and work exposure to SARS-CoV-2 assessed by a job-exposure matrix (JEM), in a large population cohort. We also estimated the population-attributable fraction among exposed subjects. METHODS: We used the SAPRIS-SERO sample of the CONSTANCES cohort, limited to subjects actively working, and with a job code available and a questionnaire on extra work activities. The following outcomes were assessed: COVID-19 diagnosis was made by a physician; a seropositivity to the ELISA-S test ('serology strict') and ELISA-S test intermediate with positive ELISA-NP or a positive neutralising antibodies SN ('serology large'). Job exposure was assessed using Mat-O-Covid, an expert-based JEM with an Index used as a continuous variable and a threshold at 13/1000. RESULTS: The sample included 18 999 subjects with 389 different jobs, 47.7% were men with a mean age of 46.2 years (±9.2 years). The Mat-O-Covid index taken as a continuous variable or with a threshold greater than 13/1000 was associated with all the outcomes in bivariable and multivariable logistic models. ORs were between 1.30 and 1.58, and proportion of COVID-19 attributable to work among exposed participants was between 20% and 40%. DISCUSSION: Using the Mat-O-Covid JEM applied to a large population, we found a significant association between work exposure to SARS-CoV-2 and COVID-19 infection, though the estimation of attributable fraction among exposed people remained low to moderate. Further studies during other exposed periods and with other methods are necessary.
RESUMEN
The chemical profiles of PM2.5 emitted from a non-road diesel generator, wood burning and cooking activities including chicken and beef charcoal grilling and general cooking activities were determined. The characterization included the carbonaceous fraction (OC/EC), water-soluble ions, elements, and organic species comprising n-alkanes, polycyclic aromatic hydrocarbons, carboxylic acids, levoglucosan, dioxins, furans, and dioxin-like polychlorinated biphenyls. The main component in the PM2.5 from the different sources was carbonaceous matter with a mass contribution to PM2.5 of 49% for cooking activities, 53% for wood burning, 66% for beef grilling, 72% for chicken grilling, and 74% for diesel generator with different OC/EC concentration ratios. The analysis of organic compounds contents using diagnostic ratios and indexes showed differences between the sources and revealed specific source markers. The water-soluble ions had the highest contribution in the cooking activities profile with 17% of PM2.5 and the least in the chicken grilling profile (1.1%). Additionally, 29 analyzed elements were identified, and their contribution varied with the sources (ranging from 1% to 11% of PM2.5). These findings could be used to differentiate these sources and could assist in the use of source apportionment methods.
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Contaminantes Atmosféricos , Material Particulado , Aerosoles/análisis , Contaminantes Atmosféricos/análisis , Animales , Bovinos , Culinaria , Monitoreo del Ambiente , Material Particulado/análisis , Agua/análisis , Madera/químicaRESUMEN
BACKGROUND: Shoulder pain, which is a widespread condition, can lead to participation restrictions in daily and professional life. However, there are few studies focusing on the differences between daily life limitations and work limitations. This study aims at identifying the factors associated with limitations in personal and professional life in a population of working age suffering from shoulder pain. METHODS: A sample of working age job seekers and workers with shoulder pain was drawn from the last general population cross-sectional French study on disability. Limitations were categorized depending on whether they related to daily life and/or work. The variables assessed were age, sex, state of health, activity restrictions, need for accommodation, and aggravating living conditions or aggravating working conditions. Separate Quasi-Poisson regressions were performed for each type of limitation. RESULTS: The sample consisted of 795 individuals of which 33.7% had no limitation, 21.7% were limited in daily life, 6.0% at work, and 38.6% in both. Factors significantly associated with daily life limitations and work limitations and their computed Prevalence Ratios (PR) were the need for accommodation (PR = 2.16), activity restrictions (PR = 2.28), perceived poor health (PR = 2.42) and low income (PR = 1.64). Aggravating living conditions and aggravating working conditions were associated with daily life limitations (PR of 1.69 and 0.63 respectively). CONCLUSIONS: The present study identifies factors associated with disability in a population with shoulder pain. Further research should be carried out in order to study health-related periods of cessation of work.
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Personas con Discapacidad , Dolor de Hombro , Actividades Cotidianas , Estudios Transversales , Humanos , Ocupaciones , Prevalencia , Dolor de Hombro/diagnóstico , Dolor de Hombro/epidemiologíaRESUMEN
Primary and secondary organic aerosols in PM2.5 were investigated over a one-year campaign at Zouk Mikael and Fiaa, Lebanon. The n-alkanes concentrations were quite similar at both sites (26-29 ng/m3) and mainly explained by anthropogenic emissions rather than natural ones. The concentrations of total Polycyclic Aromatic Hydrocarbons (PAHs) were nearly three times higher at Zouk Mikael (2.56 ng/m3) compared to Fiaa (0.95 ng/m3), especially for indeno[1,2,3-c,d]pyrene linked to the presence of the power plant. A characteristic indeno[1,2,3-c,d]pyrene/(indeno[1,2,3-c,d]pyrene + benzo[g,h,i]perylene) ratio in the range 0.8-1.0 was determined for heavy fuel oil combustion from the power plant. Fatty acids and hopanes were also investigated and were assigned to cooking activities and vehicular emissions respectively. Phthalates were identified for the first time in Lebanon with high concentrations at Zouk and Fiaa (106.88 and 97.68 ng/m3 respectively). Moreover, the biogenic secondary aerosols revealed higher concentrations in summer. The total terpene concentration varied between 131 ng/m3 at Zouk Mikael in winter to 469 ng/m3 at Fiaa in summer. Additionnally, the concentrations of the dicarboxylic acids especially for adipic and phthalic acids were more influenced by anthropogenic sources.The analysis of molecular markers and diagnostic ratios indicated that the sites were strongly affected by anthropogenic sources such as waste open burning, diesel private generators, cooking activities, road transport, power plant, and industrial emissions. Moreover, results showed different pattern during winter and summer seasons. Whereas, higher concentrations of biogenic markers were clearly encountered during the summer period.
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Contaminantes Atmosféricos , Hidrocarburos Policíclicos Aromáticos , Aerosoles/análisis , Contaminantes Atmosféricos/análisis , China , Monitoreo del Ambiente , Material Particulado/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Estaciones del Año , Emisiones de Vehículos/análisisRESUMEN
Background and Purpose- Long working hours (LWHs) are a potential risk factor for stroke. The aim of this study was to investigate this association in a large general population cohort. Methods- We used the French population-based cohort, CONSTANCES (Cohorte des Consultants des Centres d'Examens de Santé), to retrieve information on age, sex, smoking, and working hours from the baseline, self-administered questionnaire. Other cardiovascular risk factors and previous occurrence of stroke were taken from a parallel medical interview. We defined LWH as working time >10 hours daily for at least 50 days per year. Participants with primarily part-time jobs were excluded as were those with stroke before LWH exposure. We used logistic models to estimate the association between LWH and stroke, stratified by age, sex, and occupation. In additional modeling, we excluded subjects whose stroke occurred within 5 years of the first reported work exposure. Results- Among the 143 592 participants in the analyses, there were 1224 (0.9%) strokes, 42 542 (29.6%) reported LWH, and 14 481 (10.1%) reported LWH for 10 years or more. LWH was associated with an increased risk of stroke: adjusted odds ratio of 1.29 (95% CI, 1.11-1.49). Being exposed to LWH for 10 years or more was more strongly associated with stroke, adjusted odds ratio of 1.45 (95% CI, 1.21-1.74). The association showed no differences between men and women but was stronger in white-collar workers under 50 years of age. Conclusions- This large analysis reveals a significant association between stroke and exposure to LWH for 10 years or more. The findings are relevant for individual and global prevention.
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Exposición Profesional/efectos adversos , Accidente Cerebrovascular/epidemiología , Accidente Cerebrovascular/etiología , Carga de Trabajo , Adolescente , Adulto , Factores de Edad , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Factores Sexuales , Accidente Cerebrovascular/fisiopatologíaRESUMEN
BACKGROUND: Although several studies highlighted an association between occupational exposure and Dupuytren's contracture (DC), they were often limited by the highly selected population. We aimed to study this association using a job-exposure matrix (JEM) and self-reported exposure in a large cohort. METHODS: From CONSTANCES, a French population-based prospective cohort, we retrieved sex, age, social position, alcohol/tobacco intake and diabetes. Lifetime exposures were assessed by two different methods: with the biomechanical JEM 'JEM Constances', we assessed exposure to vibration and/or forearm rotation for participants whose work history was available, and from a self-administered questionnaire, we retrieved self-reported exposure to arduous work and/or carrying heavy loads. Surgery for DC was collected from the French Health Administrative database from 2009 to 2016. Multivariate logistic regression models adjusted for confounders were built to assess association between surgery for DC and occupational exposures. RESULTS: Work history was retrieved for 23 795 subjects among whom 98 underwent surgery for DC. Adjusted OR (aOR) was 2.08 (1.03-4.2) for being ever exposed to vibration and/or forearm rotation for subjects <60 years and 1.20 (0.69-2.08) for subjects ≥60 years. Data for self-reported exposure were available for 81 801 participants among whom 367 underwent surgery for DC. aOR for being exposed more than 20 years to arduous work and/or carrying heavy loads was 2.01 (1.32-3.04) for subjects <60 years and 1.04 (0.7-1.54) for subjects ≥60. CONCLUSIONS: Manual work is associated with surgery for DC among younger subjects. Monitoring exposed workers is important to prevent future functional limitations.
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Contractura de Dupuytren/epidemiología , Elevación/efectos adversos , Exposición Profesional/efectos adversos , Vibración/efectos adversos , Adulto , Anciano , Fenómenos Biomecánicos , Estudios de Cohortes , Contractura de Dupuytren/etiología , Contractura de Dupuytren/cirugía , Ergonomía/estadística & datos numéricos , Femenino , Francia/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Exposición Profesional/estadística & datos numéricos , Estudios Prospectivos , Encuestas y CuestionariosRESUMEN
We aimed to assess the predictivity of the biomechanical job-exposure matrix 'MADE' using compensation data from the National Health Insurance for work-related disorders. Data were obtained from 2013 to 2015, area under curves (AUC), sensitivity, specificity and predictive values were calculated using compensation results as reference. We collected 163 128 cases data. AUC ranged from 0.64 for shoulders disorder to 0.82 for knee disorders. If two thresholds were considered, 28.7% of the sample fit under or over those. The matrix showed a fair predictivity. Such matrix cannot replace expertise but might be a tool used for improving compensation process.
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Técnicas de Apoyo para la Decisión , Enfermedades Musculoesqueléticas/etiología , Enfermedades Profesionales/etiología , Indemnización para Trabajadores , Área Bajo la Curva , Francia , Humanos , Traumatismos de la Rodilla/economía , Traumatismos de la Rodilla/etiología , Enfermedades Musculoesqueléticas/economía , Enfermedades Profesionales/economía , Exposición Profesional/efectos adversos , Exposición Profesional/economía , Exposición Profesional/estadística & datos numéricos , Sensibilidad y Especificidad , Lesiones del Hombro/economía , Lesiones del Hombro/etiología , Indemnización para Trabajadores/economía , Indemnización para Trabajadores/estadística & datos numéricosRESUMEN
OBJECTIVES: Though the rise of big data in the field of occupational health offers new opportunities especially for cross-cutting research, they raise the issue of privacy and security of data, especially when linking sensitive data from the field of insurance, occupational health or compensation claims. We aimed to validate a large, blinded synthesized database developed from the CONSTANCES cohort by comparing associations between three independently selected outcomes, and various exposures. METHODS: From the CONSTANCES cohort, a large synthetic dataset was constructed using the avatar method (Octopize) that is agnostic to the data primary or secondary data uses. Three main analyses of interest were chosen to compare associations between the raw and avatar dataset: risk of stroke (any stroke, and subtypes of stroke), risk of knee pain and limitations associated with knee pain. Logistic models were computed, and a qualitative comparison of paired odds ratio (OR) was made. RESULTS: Both raw and avatar datasets included 162,434 observations and 19 relevant variables. On the 172 paired raw/avatar OR that were computed, including stratified analyses on sex, more than 77% of the comparisons had a OR difference ≤0.5 and less than 7% had a discrepancy in the statistical significance of the associations, with a Cohen's Kappa coefficient of 0.80. CONCLUSIONS: This study shows the flexibility and the multiple usage of a synthetic database created with the avatar method in the particular field of occupational health, which can be shared in open access without risking re-identification and privacy issues and help bring new insights for complex phenomenon like return to work.
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Bases de Datos Factuales , Accidente Cerebrovascular , Humanos , Masculino , Femenino , Estudios de Cohortes , Persona de Mediana Edad , Adulto , Artralgia/epidemiología , Articulación de la Rodilla , Salud Laboral , AvatarRESUMEN
Traffic emissions are an important source of air pollution worldwide, but in the Middle East, this problem is exacerbated by weak or no enforcement of emission regulations. Comprehensive measurements of fine PM emission factors (EFs) from road transport in the region have not yet been conducted, but such data are necessary for quantitative assessments of the health impact of transport emissions in the region. To address this need, PM2.5 samples collected inside the Salim Slam tunnel in Beirut, Lebanon were analyzed for carbonaceous matter (organic carbon (OC) and elemental carbon (EC)), water-soluble ions, elements, and selected organic compounds. The OC/EC ratio was 1.8 for the total fleet and 2.6 for light-duty vehicles (LDV), in agreement with the dominant proportion of gasoline LDV in the Lebanese fleet. A Cu/Sb ratio of 4.2 ± 0.1 was observed, offering a valuable metric for detecting brake wear emissions in subsequent studies conducted in the region. The EFs of carbonaceous matter, elements and ions generally varied by a factor 0.1 and 10 in comparison to literature values, while those for alkanes and polycyclic aromatic hydrocarbons were similar to the upper values previously reported. The average number size distribution was characterized by a single mode around 35 nm. The particles number EF (for diameters between 10 and 480 nm) was within the range of 1014-1015 particles per kg of fuel. The chemical mass balance model showed an average contribution to EF of 62% from non-exhaust sources. This study highlights the need for more enforceable stringent vehicular regulations because of the local practices (i.e., removal of catalyst) and some EF values are very high compared to other studies/countries.