Lead, isotopes and ice: a deadly legacy revealed

The earliest known use of lead was in the Neolithic period; by Roman times it was in widespread use, despite recognition that it could have adverse effects on human health. The early smelting processes were inefficient, giving rise to atmospheric pollution; as this reduced with modern improvements in furnace design, so pollution due to the addition of tetraethyl lead to motor fuel emerged. The military use of lead was a further source of environmental contamination, while individuals were exposed to lead from water pipes, paint and solder in food cans. Studies of lead in ice cores recovered from Greenland demonstrated a 200-fold increase in lead concentration from 800 BCE to the 1960s, with the greatest increase occurring after 1940. The isotope signatures of lead enabled the sources of environmental contamination to be determined: industrial lead was responsible throughout most of the last millennium, with lead in fuel making the greatest contribution in recent times. The human impact was demonstrated in studies of archaeological and modern skeletal lead levels. This paper explores the history of the use of lead and the development of an understanding of its toxicity, and examines its impact on human health

Tuberculosis in Scottish military veterans: evidence from a retrospective cohort study of 57 000 veterans and 173 000 matched non-veterans

Objective: Tuberculosis was a major cause of morbidity and manpower loss in the Armed Forces during World War II. Military control programmes commenced in the 1950s but were initially limited in scope by the many recruits who were already tuberculin positive on enlistment. The aim of our study was to examine whether veterans have an increased risk of tuberculosis compared with non-veterans. Methods: Retrospective cohort study of 57 000 veterans born 1945–1985, and 173 000 people with no record of military service, resident in Scotland, matched for age, sex and area of residence, using Cox proportional hazard analysis to compare the risk of tuberculosis overall, by birth cohort, length of service and year of diagnosis and to examine comorbidities. Results: Over mean 29 years follow-up, 69 (0.12%) veterans were recorded as having tuberculosis, compared with 267 (0.15%) non-veterans (unadjusted HR 0.90, 95% CIs 0.69 to 1.19, p=0.463). Only the 1945–1949 veterans' birth cohort was at higher risk, unadjusted HR 1.54, 95% CIs 0.98 to 2.45, p=0.061, although the difference in risk did not achieve significance. Veterans born from 1950 were at significantly reduced risk of tuberculosis compared with non-veterans after adjusting for deprivation, HR 0.67, 95% CI 0.47 to 0.95, p=0.026. The most common comorbidities were smoking-related and alcohol-related disease. The risk of comorbid hepatitis B or C was very low, in both veterans and non-veterans. No length of service was associated with an increased risk of tuberculosis in comparison with non-veterans. Conclusions: Scottish veterans born before 1950 are at moderately increased risk of tuberculosis compared with age, sex and geographically matched civilians with no record of service, although the difference is not statistically significant. Scottish veterans born from 1950 show a reduction in risk compared with civilians. Tuberculosis should be considered in the differential diagnosis of respiratory disease in the older veteran

Lymphohaematopoietic malignancies in Scottish military veterans: Retrospective cohort study of 57,000 veterans and 173,000 non-veterans

Background: Lymphohaematopoietic malignancies are common in the general population. There have been concerns that military service may be associated with increased risk as a result of occupational exposures. To date, few studies have demonstrated an increased risk, although a disability pension is payable to veterans who were present at nuclear tests and who develop leukaemia (other than chronic lymphocytic leukaemia). The aim of the study was to utilise data from the Scottish Veterans Health Study to examine the risk of lymphohaematopoietic malignancy following military service in a large national cohort of veterans. Methods: Retrospective cohort study of 57,000 veterans and 173,000 non-veterans born between 1945 and 1985 matched for age, sex and area of residence, adjusted for areal deprivation and followed up for up to 30 years, using Cox proportional hazard models to compare the risk of lymphohaematopoietic malignancy overall, by diagnosis and by sex and birth cohort. Results: We found no statistically significant difference in risk between veterans and non-veterans either for all leukaemias (Cox proportional hazard ratio 1.03, 95% confidence intervals 0.84–1.27, p = 0.773), Hodgkin lymphoma (hazard ratio 1.19, 95% confidence intervals 0.87–1.61, p = 0.272) or for non-Hodgkin lymphoma (hazard ratio 0.86, 95% confidence intervals 0.71–1.04, p = 0.110). Conclusion: Our findings provide reassurance that service in the UK Armed Forces is not associated with increased risk of lymphohaematopoietic malignancy

Non-fatal self-harm in Scottish military veterans: a retrospective cohort study of 57,000 veterans and 173,000 matched non-veterans

Purpose: Although suicide risk in veterans has been widely studied, there is little information on the risk of non-fatal self-harm in this population. We used data from the Scottish Veterans Health Study to conduct an epidemiological analysis of self-harm in veterans, in comparison with people who have never served. Methods: We conducted a retrospective, 30-year cohort study of 56,205 veterans born 1945–1985, and 172,741 people with no record of military service, and used Cox proportional hazard models to examine the association between veteran status and cumulative risk of non-fatal self-harm, overall and stratified by birth cohort, sex and length of service. We also examined mental and physical comorbidities, and association of suicide with prior self-harm. Results: There were 1620 (2.90%) first episodes of self-harm in veterans, compared with 4212 (2.45%) in non-veterans. The difference was statistically significant overall (unadjusted HR 1.27, 95% CI 1.21–1.35, p < 0.001). The risk was highest in the oldest veterans, and in the early service leavers who failed to complete initial training (unadjusted HR 1.69, 95% CI 1.50–1.91, p < 0.001). The risk reduced with longer service and in the intermediate birth cohorts but has increased again in the youngest cohort. Conclusions: The highest risk of non-fatal self-harm was in veterans with the shortest service, especially those who did not complete training or minimum engagement, and in the oldest birth cohorts, whilst those who had served the longest were at reduced risk. The risk has increased again in the youngest veterans, and further study of this subgroup is indicated

Smoking-related cancer in military veterans: retrospective cohort study of 57,000 veterans and 173,000 matched non-veterans

Background: Serving military personnel are more likely to smoke, and to smoke more heavily, than civilians. The aim of our study was to examine whether veterans have an increased risk of a range of smoking-related cancers compared with non-veterans, using a large, national cohort of veterans. Methods: We conducted a retrospective cohort study of 57,000 veterans resident in Scotland and 173,000 age, sex and area of residence matched civilians. We used Cox proportional hazard models to compare the risk of any cancer, lung cancer and other smoking-related cancers overall, by sex and by birth cohort, adjusting for the potential confounding effect of socioeconomic deprivation. Results: Over a mean of 29 years follow-up, 445 (0.79 %) veterans developed lung cancer compared with 1106 (0.64 %) non-veterans (adjusted hazard ratio 1.16, 95 % confidence intervals 1.04–1.30, p = 0.008). Other smoking-related cancers occurred in 737 (1.31 %) veterans compared with 1883 (1.09 %) non-veterans (adjusted hazard ratio 1.18, 95 % confidence intervals 1.08–1.29, p < 0.001). A significantly increased risk was observed among veterans born 1950–1954 for lung cancer and 1945–1954 for other smoking-related cancers. The risk of lung cancer was decreased among veterans born 1960 onwards. In comparison, there was no difference in the risk of any cancer overall (adjusted hazard ratio 0.98, 95 % confidence intervals 0.94–1.01, p = 0.171), whilst younger veterans were at reduced risk of any cancer (adjusted hazard ratio 0.88, 95 % confidence intervals 0.81–0.97, p = 0.006). Conclusions: Military veterans living in Scotland who were born before 1955 are at increased risk of smoking-related cancer compared with non-veterans, but younger veterans are not. The differences may reflect changing patterns of smoking behaviour over time in military personnel which may, in turn, be linked to developments in military health promotion policy and a changing military operational environment, as well as to wider societal factors

The Scottish veterans health study: a retrospective cohort study of 57,000 military veterans and 173,000 matched non-veterans

Introduction: Although the health of military personnel who have taken part in specific conflicts has been studied throughout the 20th century, there is a paucity of evidence on the long-term overall impact of military service on health. This thesis describes the establishment of and findings from the Scottish Veterans Health Study, a retrospective cohort study comparing the health outcomes of veterans with those of people with no record of service, in order to determine whether the long-term health of military veterans living in Scotland differed from that of people who had never served in the armed forces. Methods: The study population comprised all 57,000 military veterans born between 1945 and 1985 who were resident in Scotland both before and after military service, together with a 3:1 comparison group of 173,000 people with no record of service, matched for age, sex and postcode sector of residence. The demographic data were extracted from the National Health Service Central Registry database and were linked electronically to the National Health Service Scottish Morbidity Record and national vital records data for acute and psychiatric hospital admissions, psychiatric day-case admissions, cancer registrations and death certificate data. Survival analysis was used to determine hazard ratios for those health conditions and outcomes considered to be of a priori interest, overall, by sex, by birth cohort and by length and period of service, both univariately and after adjusting for deprivation. Results: Veterans were at significantly increased risk of cardiovascular disease compared to non-veterans overall, and of acute myocardial infarction, stroke and peripheral arterial disease specifically. Subgroup analysis showed the increased risk to be confined to veterans born between 1945 and 1959, reducing in more recent birth cohorts. The risk was highest in veterans who left after only a short period of service (Early Service Leavers), whilst those who served for longest exhibited a similar risk of cardiovascular disease to all non-veterans. Veterans were at no higher overall risk of cancer than non-veterans, although there were major differences in the risk of specific cancers, which changed over time. The oldest veterans had an increased risk of cancer of the lung, oropharynx and larynx, oesophagus and stomach; the risks of these cancers reduced in more recent birth cohorts. The 1960-1964 birth cohort showed an increased risk of both bladder cancer and pancreatic cancer in comparison with non-veterans. There were increased risks of ovarian cancer in veteran women compared with non-veterans, and of breast cancer in longer-serving women. The risk of cervical cancer decreased in more recent birth cohorts. There were no differences in the risk of colorectal cancer or prostate cancer in veterans, overall or in any subgroup. There was no clear evidence of increased risk of lymphohaematopoietic cancer in veterans. Veterans were at increased risk of motor neuron disease, but not of multiple sclerosis. Veterans were at increased risk of peptic ulcer disease for all birth cohorts up to the mid-1960s but not thereafter; the risk was highest in those with the shortest service. Hepatitis C was less common in veterans than in non-veterans, in all subgroups. Analysis of mental health outcomes showed that the greatest burden of ill-health was among Early Service Leavers, whilst veterans who completed at least a minimum length of engagement were not at increased risk compared with non-veterans, except for post-traumatic stress disorder. The results for post-traumatic stress disorder, in both veterans and non-veterans, demonstrated a complexity which could not be reconciled with any operational exposure or conventional clinical pattern, but which may have reflected a ‘hidden iceberg’ of unmet need in the late 1990s which was uncovered by increasing awareness of the condition. Longer service was generally associated with better mental health. Veterans were at no greater risk of suicide than non-veterans; the risk was independent of length of service. Veteran women exhibited a risk profile for mental health outcomes which more closely resembled that of veteran men; this was especially marked for suicide. Veterans were not at increased risk of alcoholic liver disease overall; the only subgroup to show an increase in risk was Early Service Leavers who had completed training, and there was also evidence of increased risk of some alcohol-related cancers in trained Early Service Leavers. Interpretation: Older veterans demonstrated an increased risk of smoking-related ill-health, including cardiovascular and respiratory disease and the smoking-related cancers, which is consistent with reported high rates of military smoking in the 1960s and early 1970s. Overall, there has been an improvement in health of veterans compared with the non-serving population in more recent generations, suggesting that the increased emphasis on health promotion and physical fitness in the armed forces since the late 1970s has been effective. Major alcohol problems were no more common in veterans than in the wider community, and were most likely to affect those who left earliest, although not those who left whilst still in training. Longer service was generally associated with better long-term health. Early Service Leavers had poorer health outcomes than longer-serving veterans, but the ability to stratify by length of service demonstrated that the poorest outcomes were in those who did not complete initial training. It is likely that their long-term health outcomes have been predominantly influenced by pre-service and post-service health and behavioural factors which, at a pre-service level, may have also contributed to their failure to complete the minimum military engagement, rather than by their short period of military service. The early period of service appears to act as an extension to the screening process for entry to service, filtering out those who prove least suited to service. The Early Service Leavers therefore form a ‘less healthy leaver’ group which is the counterpart to the longer-serving ‘healthy worker effect’; their status as veterans means that they can be identified within the community, unlike most other occupational leaver groups, but their poorer long-term health is unlikely to be due to military occupational factors. Improved understanding of the determinants of veterans’ health will inform the provision of appropriate health and community services to meet their needs

Chronic obstructive pulmonary disease in Scottish military veterans

Introduction: Smoking is a major risk factor for chronic obstructive pulmonary disease (COPD). Serving military personnel have previously been shown to be more likely to smoke, and to smoke more heavily, than civilians, but there is no clear consensus as to whether in later life, as veterans, they experience a higher prevalence and mortality from COPD than do non-veterans. We examined the risk of COPD in Scottish veterans and assessed the impact of changes in military smoking. Methods: Retrospective 30-year cohort study of 56 205 veterans born 1945–1985, and 172 741 people with no record of military service, matched for age, sex and area of residence, using Cox proportional hazard models to examine the association between veteran status, birth cohort, length of service and risk of COPD resulting in hospitalisation or death. Results: There were 1966 (3.52%) cases of COPD meeting the definition in veterans, compared with 5434 (3.19%) in non-veterans. The difference was statistically significant (p=0.001) in the unadjusted model although it became non-significant after adjusting for deprivation. The highest risk was seen in the oldest (1945–1949) birth cohort and in veterans with the shortest service (Early Service Leavers). The risk was significantly reduced in veterans born from 1960, and in those with over 12 years' service. Conclusions: Our findings are consistent with falling rates of military smoking since the 1960s, and with the reduction in smoking with longer service. The oldest veterans, and those with the shortest service, are least likely to have benefited from this, as reflected in their higher risk for COPD

Early adoption of screening and the changing pattern of cervical cancer in UK Military women: evidence from the Scottish Veterans Health Study

Objective: To examine the risk of cervical cancer in a large national cohort of military veteran women followed up for up to 30 years. Methods: Retrospective cohort study of 5235 veteran women born between 1945 and 1985, and 20 703 women with no record of service matched for age and area of residence, using Cox proportional hazard models to compare the overall risk of cervical cancer and by year of birth. Results: During the follow-up period 1981–2012, there were 18 (0.34%) cases of cervical cancer in the veteran women compared with 81 (0.39%) in the non-veterans. The difference was not statistically significant overall (adjusted HR 0.95, 95% CI 0.57 to 1.59). When analysed by the year of birth, veteran women born in 1958 and earlier had a non-significantly higher risk than non-veterans (adjusted HR 1.24, 95% CI 0.68 to 2.26), while veteran women born after 1958 had a non-significant reduction in risk (adjusted HR 0.51, 95% CI 0.18 to 1.44). Conclusions: Women born after 1958 who have served in the Armed Forces are at reduced risk of cervical cancer compared with women who have never served, and compared with older veteran women. Small numbers of cases precluded statistical significance. The change in risk pattern in veteran women coincided with the introduction of cervical screening in the Armed Forces, which predated the UK national programme, and provides evidence for the long-term effectiveness of the Armed Forces’ sexual health strategy. The impact of recent changes in the screening age, and of human papillomavirus immunisation, should be monitored in the future

Road traffic accidents in Scottish military veterans

Road traffic accidents (RTA) are recognised to be an important cause of death and injury in serving military personnel but little is known about the risk in veterans. We used data from the Scottish Veterans Health Study to examine the risk of RTA in a large national cohort of veterans, in comparison with people who had never served. We conducted a retrospective cohort study of 57,000 veterans and 173,000 non-veterans, followed up for up to 30 years, using survival analysis to compare risk of RTA injury. Subgroup analysis was used to explore trends by birth cohort and length of service. Overall, veterans had a higher risk of RTA (Cox proportional hazard ratio (HR) 1.17, 95% confidence intervals (CI) 1.14–1.20). The risk was highest in the veterans with the shortest service (early service leavers), including those who did not complete initial military training (HR 1.31, 95% CI 1.23–1.40). The mean age at first RTA was 34 years, irrespective of age at leaving service, and the greatest increase in risk was in veterans born in the 1960s, but veterans born after 1970 showed no increase in risk. We have therefore demonstrated that the increased risk of RTA observed in serving military personnel persists in veterans through the fourth decade of life. The high risk in early service leavers is likely to be related to risk factors other than military service, including previous childhood adversity. Recent Ministry of Defence road safety programmes may now be reducing the long-term risk of RTA injury

Motor neurone disease and military service: evidence from the Scottish Veterans Health Study: Table 1

Objectives: In 2003, it was reported that motor neurone disease was linked to military service in the 1990–1991 Gulf War. A large study in the US confirmed an association with military service but found no association with specific conflicts or length of service. Non-veteran studies have suggested an association with physical activity, smoking and other risk factors. We used data from the Scottish Veterans Health Study to investigate the association between motor neurone disease and military service in UK veterans. Methods: Retrospective cohort study of 57 000 veterans born 1945–1985, and 173 000 demographically matched civilians, using Cox proportional hazard models to compare the risk of motor neurone disease overall, and by sex, birth cohort, length of service and year of recruitment. We had no data on smoking prevalence. Results: Veterans had an increased risk of motor neurone disease compared with non-veterans (adjusted HR 1.49, 95% CI 1.01 to 2.21, p=0.046). The increase was independent of birth cohort, length or period of service, or year of recruitment. Risk was associated with a history of trauma or road traffic accident in veterans and non-veterans. Conclusions: We confirmed an increased risk of motor neurone disease in military veterans, although the absolute risk is extremely low. We found no evidence that the increased risk was associated with any specific conflict. We could not rule out that smoking (and perhaps other lifestyle factors) may be responsible for our findings. Trauma may play a role in the increased risk but further studies are needed