The impact of sulfur mustard on quality of life and mental health in Kurdish survivors in Sweden, thirty years after exposure

Chemical warfare agents (CWAs) have been used during World War I and II, the Holocaust, and sporadically in many international, regional, and civil wars despite global legal prohibition [1‐3]. Terrorist groups have used CWAs to incite fear and instability among civilian populations [1, 3, 4]. Industrial chemical accidents and environmental disasters also contribute to chemical exposure [5, 6]. Sulfur mustard (SM) is one of the most widely used CWAs. It was extensively employed in the Iraq–Iran war (1980–88) [3]. During al-Anfal genocide (1987–1991), the Iraqi state used SM and sarin against Kurdish political organizations, armed forces, and civilian populations in the present-day Kurdistan Region of Iraq (KRI) [7]. The chemical bombardment of Halabja city on March 16, 1988, left thousands dead and injured for life and remains unprecedented in the post-World War II era [8]. The survivors in Halabja were exposed to different CWAs, e.g., SM and sarin [9]. Thus, SM has a higher morbidity rate than nerve agents and can cause late-onset biopsychosocial complications [10]. SM-related health effects develop gradually—for example, respiratory symptoms and psychological disorders such as mood and depressive disorders, prolonged post-traumatic stress disorder, and chemical contamination anxiety impact all aspects of survivors’ lives [11]. Moreover, SM-exposed people’s health deteriorates over time, resulting in greater healthcare service use [3, 9], possibly impacting survivors’ quality of life (QoL) [12].

Ongoing wars in the Middle East and international conflicts have forced hundreds of Kurdish, Syrian, and Iranian CWA survivors to migrate and resettle abroad (e.g., Sweden). There is an urgent need for more knowledge to improve medical care and treatment in preparation for CWA exposure and survivors. Previous studies reported that female survivors of CWA exposure experienced more pronounced psychosocial adverse effects than males [9, 13].

Survivors at risk for severe chronic disease and impaired QoL in their later years need follow-up healthcare. There is limited knowledge regarding the mental health and QoL of persons exposed to SM in western countries. However, the long-term impacts of CWA, e.g., SM on QoL and mental health in Iranian veterans, are highlighted in multiple studies [11, 14, 15].

This study aimed to assess, evaluate, and compare the QoL and mental health condition of Kurdish survivors resettled in Sweden (exposed) compared to a nonexposed group of Kurdish residents in Sweden (i.e., controls).

Scholars have used the Short Form Health Survey 36 (SF-36) questionnaire to obtain an overall QoL score and use public health-related evidence to influence policymakers [16]. Similarly, clinicians employ the self-rated Montgomery-Åsberg Depression Rating Scale (MADRS-S) as a supplementary assessment to monitor depression severity [17].

We hypothesized that survivors in the exposed group would report impaired QoL and poor mental health compared to the matched nonexposed group.

There were 18 participants in the exposed group (n = 18, mean age = 51.3 ± 8.2 years, 50% women) and 30 in the nonexposed group (mean age = 48.7 ± 10.3 years, 47% women). Details of participants’ demographic, socioeconomic, and nature of SM exposure variables are presented in Table 1. There were no significant differences concerning sex, age, body mass index, or marital status between groups. Higher unemployment and a low education level were observed in the exposed than in the nonexposed group. Furthermore, 61% (11 subjects) in the exposed group experienced primary SM exposure.

This study found that SM-exposed survivors had significantly worse and more impaired QoL and reported a high level of moderate depressive symptoms compared to nonexposed controls three decades after the exposure.

Participants in the exposed group reported significantly lower scores in each of the eight RAND SF-36 variables and the two combined physical and mental well-being scores compared with the nonexposed group, which indicates an obvious, worse QoL.

The most pronounced differences regarding QoL variables were social function, bodily pain, vitality, and general perception of health. Overall, the survivors had worse mean scores for mental than physical well-being, possibly because the mental symptoms stemming from SM exposure were challenging to identify and subsequently hard to treat—regardless of healthcare access. Conversely, physical well-being depends on healthcare access and can vary according to local resources. It may be easier for exposed participants to receive treatment for physical symptoms as opposed to psychological ones.

The apparent discrepancy in reported impaired QoL and worse mental well-being in the exposed group compared with the nonexposed may be attributed to the fact that participants in the exposed group were exposed to SM (Table 1). Notably, a previous study showed that more significant organ damage caused more acute and long-term illness among exposed persons than the controls [14]. Thus, direct SM exposure experienced by the survivor’s group may have led to harsher physical outcomes.

The impaired mental illness observed are some apparent factors behind reduced workability and unemployment, previously reported among SM-exposed survivors, that may contribute to impaired QoL [2, 9]. This might be attributed to post-exposure health conditions (e.g., respiratory symptoms and fatigue) [2, 9]. Furthermore, the associations between chronic health conditions, low QoL, and unemployment are well known among patient groups with no CWAs exposure [23]. Another notable pattern that emerged is the lower level of education among survivors. Previous research indicates that education is independently linked with employment status, and studies have reported an association between poor health and low education [24]. It might be explained by the fact that SM-exposed survivors have difficulties following education due to post-exposure symptoms, e.g., reduced concentration and mental illness. Despite the welfare system in Sweden, unemployment results in low income, a contributing factor to poor mental health and low QoL and vice versa [25].

Mental health is an essential component of good QoL. SM exposure results in late-onset psychological issues: prolonged post-traumatic stress syndrome, depression, and chemical contamination anxiety [3, 9]. Predictably, participants in the SM-exposed group reported predominantly higher scores for symptoms of depression than the nonexposed group (Table 3). Our MADRS-S findings highlighted more severe depressive symptoms among survivors, with mean MADRS-S scores of 22.9 points (Table 3). These results were in line with the outcomes of RAND SF-36 scores, in which survivors rated their combined MCS lower than their PCS (Table 2). Additionally, the most pronounced differences were that survivors experienced a four-fold higher risk for suicidal thoughts, lassitude, and inability to feel, a three-fold higher risk for pessimistic thoughts, reduced appetite, and reported sadness, and a two-fold higher risk for reduced sleep (Table 3). These symptoms are understood as post-exposure complications and have been reported in SM-exposed survivors in Iran and Kurdistan-Iraq and even in World War I veteran survivors [2, 3, 9].

The pathophysiological aspects of neuropsychiatric illnesses and the inevitable social effects are not thoroughly studied in SM-exposed survivors. However, brain impacts structurally and functionally were documented after exposure to SM or its analog and in veterans with War-related PTSD [26‐28]. A recent study has revealed that the prevalence of post-exposure reduced sleep is associated with a lower level of serum melatonin (a hormone playing an essential role in promoting sleep) in SM-exposed patients [28]. Furthermore, brain damage has been revealed in mice exposed to SM analog vesicant [26]. Fatigue and poor vitality are linked to SM post-exposure respiratory symptoms and reduced sleep affecting many aspects of an exposed individual’s life. Also, functional magnetic resonance imaging in veterans with Gulf War-related PTSD showed a reduced hippocampus volume compared with the healthy control group [27]. Several studies, have reported that the mental illnesses and symptoms in SM-exposed survivors are associated with damage to the nervous system [2, 3, 9]. The brain “abnormalities” in SM-exposed people might impact their cognitive ability in the long-term [26‐28]. This could explain the relationship between exposure to SM and poor mental health conditions, low QoL, and low education level despite the extreme complexity of the interrelation between these factors. But, despite these nuances, multiple studies have indicated that exposure to CWAs—even the fear of being exposed to them—leads to a chronically impaired health status and low QoL [3, 29]. These factors were strongly associated with low academic performance and unemployment [24], which coincides with our current findings.

However, the survivors in the exposed group had consistent access to public healthcare services and an established welfare system. Despite this, survivors in Sweden occupy marginal social, economic, and cultural positions and have a poor state of health. A study showed that foreign-born people rated their health poorer than those born in Sweden [30]. This study demonstrates that SM exposure is associated with enduring long-term poor mental well-being and impaired QoL. Consequently, the results indicate that the healthcare service systems might need new adapted approaches and increased knowledge for the early identification of mental illness among SM-exposed survivors.

The current study showed slightly non-significant gender differences in survivors’ perception of QoL and mental illness (Tables 5 and 6), which may be explained by the small sample size. Another explanation might be the more independent sex, economic, and social possibilities and equalities in Swedish society. Thus, survivors have enjoyed an equal individual mode of existence and access to healthcare services.

A new study showed that having a good relationship with a partner was associated with perceived good health [31]. In our previous study among survivors in Halabja, we revealed that SM exposure survivors suffered from poor marital relations and female survivors reported difficulties getting married which might contributed to impaired QoL [13].

Furthermore, survivors were characterized by a significantly higher degree of unemployment and lower education than the nonexposed group, which was consistent with previous studies [9, 15, 32]. The education and unemployment pathways partly mediated the outcome differences between exposed and nonexposed groups (Fig. 1). Nevertheless, exposure to SM has the dominant direct impact on mental health and QoL in terms of both physical and mental well-being and the gravity of depression (Table 4).

Remarkably, the exposed group had lower QoL and combined MCS compared to the studies conducted among Iranian male veteran survivors living in Iran [14, 15]. Furthermore, our results showed that SM-exposed survivors in Sweden reported higher(better) scores in terms of PCS variables; physical function, role physical, bodily pain, and general health than the Iranian male survivors of CWA. However, there were slight differences in MCS variables; social function, role emotional, vitality, and mental health [15]. This comparison has limitations, including the number and sex of the participants. However, the male survivors in the exposed group in our study scored about seven points lower on mean MCS than the Iranian male survivors[14]. This can be attributed to the lack of experience, clinician knowledge, and guidelines for treating exposed persons in the Swedish healthcare system or other barriers male participants may have encountered, such as language barriers and social exclusion. Another explanation might be that the Iranian war survivors were consistently provided the highest quality of long-term care services and were treated and hospitalized after SM exposure [3, 33].

Nevertheless, the apparent differences in impaired QoL and high depressive symptoms in the SM-exposed compared with the nonexposed group highlights the reinforced possible association between SM exposure and higher unemployment levels, low education levels, low QoL, and long-term poor mental well-being among survivors. Our results were confirmed by previous studies that determined CWA survivors experienced poor mental well-being and impaired QoL [3, 11, 12, 14, 15, 33].

This study had some limitations. First, low participant numbers resulted in minor frequencies, which might limit generalizability to larger populations. However, the interesting results of this paper play an essential role in giving a voice to the everyday challenges and difficulties of this almost-forgotten group of patients. A second limitation was that our results were based on lived experiences, memories, and reported symptoms that were part of participants’ narratives. However, having a laboratoristic investigation of being SM-exposed is impossible, and access to medical journals is not possible due to the lack of medical journals. The survivors in Halabja were exposed to different CWAs, e.g., SM and sarin [9], and therefore, it is difficult to rule out overlapping and synergistic effects on the participants. Thus, unlike sarin, SM has lower mortality but can cause late-onset biopsychosocial complications [10]. In other studies, the SM-exposed participants have been recruited from a database managed by the authorities [9, 32]. Furthermore, it is impossible to comment on the causality between exposure to SM and this paper's outcomes due to the study's observational nature. Finally, direct or indirect experiences of other traumatic violence may have influenced the outcomes of MADRS-S and RAND SF-36, although the results were consistent with other studies [3, 11, 15].

Exposure to SM has obvious long-term severe impacts on survivors’ QoL and mental health. We suggest that in addition to the medical focus on this group of patients, one goal within a healthcare system should be to optimize survivors QoL and psychosocial well-being. These findings indicate that SM survivors may benefit from the early identification of a mental illness and more support to promote QoL.