The aim of the present paper was to use a systematic approach to explore the literature and determine whether working conditions and occupational health differ between immigrant and native workers in Europe and Canada.
The most robust result in the present analyses is the higher risk of work injuries in immigrant than in native workers in studies from different countries and with different designs (e.g., occupational injury records, national surveys and patient records) [14, 20, 29, 31, 40, 50, 65, 67, 71, 85, 88]. However, one study that compared immigrants and natives with similar jobs and work tasks (bus drivers) did not find a higher risk among immigrants [66]. Different study designs and the fact that many of the studies were based on patient samples without access to the population at risk make it difficult to compare the risk estimates in all studies. Register-based population studies are considered the gold standard for estimating injury rates in the general population; however, a common limitation in all the included studies was that these studies did not account for illegally employed workers, as well as legally workers, who were not found in the national registries. Nevertheless, our findings are consistent with the results from two previous reviews based primarily on studies from the United States (U.S.) [8, 14]. Preventing work injuries in immigrant workers should take a high priority at both the government and enterprise levels.
Across a large number of survey studies, our analyses consistently show that the prevalence rates of bullying [18, 43] and perceived discrimination [15, 19, 36, 41, 46, 48, 51, 86, 91] were higher in immigrants than in natives. However, the different definitions and measures of bullying and discrimination used in these studies rules out the possibility of comparing prevalence estimates. Immigrants do not generally appear to experience poorer psychosocial working conditions than natives within similar occupational groups, and psychosocial working conditions appear to be equally important for health in both immigrants and natives [17, 38, 44, 49, 54, 55, 87]. Nevertheless, results of studies of the general working population show that immigrants are more likely to be employed in jobs with a lower level of autonomy and opportunities for development [35, 39, 77, 80]. In addition, employment conditions such as temporary work [15, 21, 33, 73], lack of work contracts [33] and over-qualification [34] are prevalent and may be important work factors to take into account, especially in studies of recent immigrants [26, 72]. Further studies are needed to replicate these results in different countries and groups of immigrants.
Only a few studies have addressed the physical and chemical working environment of immigrant workers. We did not identify any studies of the health consequences related to physical and chemical exposures in the workplace. Such health consequences may manifest several years after the exposure and are therefore not straightforward to investigate, which may partly explain the lack of studies in this field. A previous review reported that studies of exposure and health problems tended to focus on specific exposure in specific occupational groups, such as pesticide exposure among agricultural workers [8]. However, these studies were conducted in the U.S. Thus, the present study shows that physical or chemical exposures among immigrant workers have been neglected in the European research literature. One possible explanation is that studies of exposure to physical or chemical factors at work may have focused on the exposure and effect in certain occupational groups, as in the U.S., without reporting other characteristics of the exposed groups, such as immigrant status.
Our study shows that immigrant workers report higher levels of poor SRH [21, 23, 25, 35, 47, 82] and mental distress [10, 25, 32, 35, 52, 55, 69, 84, 87, 89] than do natives, which is consistent with the findings of two previous reviews [115, 116]. Our analysis also showed that most [28, 37, 42, 45, 81,82,83] but not all studies [23, 24, 73] have reported a higher risk of sick leave and disability pension among immigrants compared with natives. The evidence that occupational factors may partly contribute to the excess risk of sick leave and disability pension observed among immigrants is sparse, although a few Scandinavian studies support this observation [28, 42, 82]. However, differences pertaining to working conditions were reported to have a small or negligible impact on the increased risk of poor mental health or SRH among immigrants compared with natives in studies from Scandinavia [35, 84], Spain [25] and the Netherland [52].
Our systematic review indicated a need for more high-quality epidemiological studies investigating the relationship between working conditions and occupational health; that is, there are few prospective cohort studies that take various workplace characteristics, immigrant status and baseline health into account.
Most of the included studies of immigrant workers were cross-sectional and relied on self-report. Although self-reported data are an important source of information about the working environment and health in the population, both cognitive and situational factors may influence the validity of the data. Several of the studies used non-validated instruments to measure work exposure or provided little information about the items or instruments used to measure the variables of interest. Moreover, different factors (e.g., language barriers and differences in semantic meanings, expectations and frames of reference) can influence how immigrants evaluate or assess their work environment and understand and interpret the questions and survey context. In addition, a lack of consistency in the assessment methods and instruments make it difficult to compare risk and prevalence across studies of immigrant workers in different study contexts.
Another important consideration is the representativeness of the samples recruited. Immigrants are a heterogeneous group, and individual immigrants may come from different countries, migrate for different reasons, live in different recipient countries and work permanently or for a limited period. Over-sampling is often required to yield sufficient statistical information, and many studies have included small sample sizes that may not have been drawn randomly. Moreover, the lack of access to some populations, such as immigrant workers on short stays or undocumented migrants, is another obstacle.
Most studies of immigrant workers’ occupational exposures and health evaluated in our review focused on differences between immigrants and the native population in the host country; these provide some insights into differences and similarities in occupational exposure and present health status. However, factors such as the diversity of immigrants in terms of their age, sex, country of origin and destination, socio-economic status, the type of migration influence the possibility to perform simple comparisons of the occupational health status between immigrants and natives [7, 117]. Moreover, the “healthy immigrant effect” hypothesis suggesting that migrants are initially healthier than non-migrant populations due to the selection of healthy migrants at migration, but later deterioration of effect because of exposure to risks in host countries, further complicates this issue [117, 118] . Thus, the lack of prospective studies that have included factors that can affect health at different stages before, during and after migration limits the ability to determine the extent to which factors in the work environment, together with other risk factors, may contribute to the risk of illness and disease.
Few studies have evaluated the occupational health risks of immigrant populations. This is the first systematic review to summarize the literature on all aspects of working conditions and occupational health in immigrant workers in Europe and Canada. We searched the literature using a number of databases and hand searched the reference list of all the included studies to minimize the risk of missing important studies. The selection of articles in English or Nordic languages and our strict inclusion criteria of original, quantitative, peer-reviewed studies may have led us to overlook relevant documentation published in reports, books or websites that may shed light on this topic. Importantly, the study population in this review represents a narrow spectrum of socio-economic and cultural environments, which makes it impossible to generalize the results to immigrant workers in all parts of Europe or in other parts of the world.
One limitation of this review is the heterogeneity of the methodology used in the included studies. Large differences were observed between the studies in terms of sample size, recruitment methods and assessment of working conditions and occupational health, and these variations restrict our ability to compare and combine the findings of individual studies. Hence, when accounting for the large number of studies with different study aims, populations and methodological approaches, the results will inevitably be a simplification, summary and selection of information and knowledge. Nevertheless, we believe that some general conclusions can be drawn based on the current knowledge about the working conditions and health of immigrants.
