Natural response to range of challenges or life events \200 Not necessarily harmful; can improve performance in some situations \200 In some individuals may be a risk factor for poor mental ill health. Epidemiology \200 435,000 people in the UK reported work related stress, anxiety, or depr ession in 2006/7. See M http://www.hse.gov.uk/statistics/overall/ hssh0910.pdf 20% of the UK working population \200\230very \200\231 or \200\230extremely \200\231 stre ssed \200 More than 9.3 million working days are lost each year in the UK from work-related mental ill health or \200\230stress \200\231 Individual, local, organizational, and cultural factors affect the level of reported stress The sharp rise in cases of reported stress contrasts with the relatively minor secular changes in prevalence of mental illness. Clinical features Individual symptoms \200 \200 Behavioral changes \200 Increased irritability \200 Impulsive behavior \200 Social wi thdrawal \200 Less able to relax at home \200 Working more than usual \200 Increased use of caffeine, cigarettes or alcohol, addictive drugs or other substances 1 Remember stre ss is not an ill- ness and all these symptoms are non-speci \201 c Reduced self-con \201 dence Feelings of tension and nervousness Self-doubt Indecisiveness Increased irritability Fluctuations of mood Sleep dif \201 culties Poor concentration \200\230Burn-out \200\231 \200 \200 \200 \200 \200 \200 Adjustment disorders \200 Mainly anxiety \200 Temporal association with an apparent str essor \200 Signi \201 cant impairment of social and occupational functioning is required to establish the diagnosis depressive symptoms 13_Smedley_Chap13.indd 308 1/2/2013 1:34:25 PM STRESS 1: RECOGNITION AND ASSESSMENT 309 Causal exposures/industries The Management Standards HSE describes a system to identify risk factors at work (see b p. 134, Organizational psychosocial factors) \200 \200 \200 \200 \200 Demand Change Relationships Control Role Support Workers in several sectors report higher levels of stress, but that does not mean these sec tors are more stressful: \200 Secondary school teachers \200 HCWs \200 Call center op eratives \200 Emergency service workers (police in particular). Sector-speci \201 c guidance on risk management is available on the HSE website. M http://www.hse.gov.uk/stress/information.htm Individual susceptibility \200 Previous history of work-related stress \200 Co-existing non-work-related stress (e.g. domestic upheavals) \200 Previous history of mental health problems \200 High alcohol intake \200 Excessive personal expectations, Type A persona lity. Diagnostic assessment \200 Exclusion of psychiatric disorder: e.g. major depressive illne ss, generalized anxiety disorder, obsessive \200\223compulsive disorder (OCD) Identi \201 cation of potential occupational stressors: including interpersonal con \202 ict, bullying, harassment, or grievances, by risk assessment Identi \201 cation of non-work stressors \200 Identify current coping strategies: are th ey helpful, can they be in \202 uenced by individual mentors or training? \200\230Post-traumatic stress disorder \200\231 has very speci \201 c diagnostic criteria and the term should not be used if these are not met. Prognosis \200 In general, excellent \200 Early intervention critical to successful out come (see b p. 311, Stress 2: interventions/risk controls). 13_Smedley_Chap13.indd 309 1/2/2013 1:34:25 PM CHAPTER 13 Psychiatric disorders 310 Time off work \200 Can be detrimental to recovery of the employee unless the condition in terferes signi \201 cantly with performance at work. As far as possible, with adequate sup port and adjustments, it is advisable to keep the employee at work If time off work is needed, there should be clarity about reason for absence, return to work process, and how progress will be monitored. Relevant legislation and guidance \200 Protection from Harassment Act 1997 \200 Tacklin g stress: The Management Standards Approach (1997). M http://www.hse.gov.uk/stress/standards/ 13_Smedley_Chap13.indd 310 1/2/2013 1:34:25 PM STRESS 2: INTERVENTIONS/RISK CONTROLS 311 Stress 2: interventions/risk controls Primary (preventing stress in the workforce) See b p. 134, Organizational psychosocial factors, Risk controls. \200 Stressor identi \201 cati on and risk assessment \200 Attention to job design \200 Skills and leadership training at all levels in the organization \200 Flexible working as part of work \200\223life bal ance program. Secondary (preventing recurrence or exacerbation in an individual with work-related stress) \200 Attentive and compassionate management \200 Cognitive behavioral therapy (CBT) \200 Change management \200 Assertiveness training \200 Time management \200 Interpe rsonal skills training. Interventions for the individual with work-related stress Psychological support through occ upational health (OH) and employee support program: \200 Con \201 dential self-referral service available to all employees \200 Access to clinical psychology \200 Therapy tech niques aimed at problem-solving \200 Highly focused individualized approach \200 Emphas is on therapeutic bene \201 ts of work. Including round-table discussions \200 Involving employee, OH +/ \200\223 treating psychologist, patient \200\231s manager, and HR taking a shared problem-solving approach to deal with stress issues Particularly useful if patient is off work and where interpersonal con \202 ict has complicated the situation Enabling early agreement on a graduated rehabilitation program back to work, establishing job de \201 nition, hours and days of work, etc. Educating managers on nature of stress-related dif \201 culties and ensuring their commitment to the rehabilitation program, including preparation of the rest of the team for the employee \200\231s return from sickness absence. Further information and guidance Health and Safety Executive. (1999). Managing Stress at Wo rk . HSE, Sudbury. Health and Safety Executive. (2001). Tackling work-related stress: a man ager \200\231s guide to improving and maintaining employee health and wellbeing . HSE, Sudbury. Health and Safety Executive. (2004). Stress Management Standards . HSE, Sudbury. Calnan M, Wainwright D (2002) Work stress: the making of a modern epidemic . Open University Press, London. Available at: M http://www.hse.gov.uk/stress/index.htm 13_Smedley_Chap13.indd 311 1/2/2013 1:34:25 PM CHAPTER 13 Psychiatric disorders 312 Post-traumatic stress disorder 1: diagnosis and risk factors Effects of severe stress Extre mely disturbing events can have marked and sustained emotional effects. Warfare has provide d most evidence and it has generated many diagnoses, including Da Costa \200\231s syndrome, soldier \200\231s heart, and shell shock. The Vietnam War led to post-traumatic stress dis order (PTSD) enter- ing the Diagnostic and Statistical Manual of Mental Disorders (DSM III) (American Psychiatric Association, 1980). The current revision is the DSM-IV (1994 America n Psychiatric Association, 1994). The nosology used most frequently in the UK is the ICD-10 (WHO, 1992). 1 Epidemiology \200 Community samples: no community-based survey of PTSD has been conducted in the UK and most data derive from the USA. Note the obvious sociocultural differences, i ncluding availability of \201 rearms. \200 lifetime prevalence for adult exposure to tr auma 3.9 \200\22389.6% \200 lifetime PTSD prevalence rates 1.0 \200\22311.2% \200 risk of PTSD is greater for 5 than 4 (20.4% vs. 8.1%) \200 younger urban populations report hi gher incidence (up to 30.2% for 5 and 13% for 4 ) Selected samples: 4% of UK Armed Forces deployed to Iraq and Afghanistan \200 20% of those who have experie nced physical assault. Diagnosis and assessment (ICD-10 criteria) \200 Stressor criterion: victim must have been exposed to a stressful event or situation (either short- or long-lasting) of an exceptionally threatening or catas trophic nature, which is likely to cause pervasive distress in almost anyone. Symptoms: repetitive, intrusive recollection or re-enactment in memories, daytime imagery or dreams commonly fear and avoidance (i.e. reminders of the event) \200 usually hyperarousal, such as an exaggerated acoustic startle response and hypervigilance. 1 Do not use the term PTSD loosely. Acute, chronic, and delayed PTSD \200 The ICD-10 is not very speci \201 c: The onset [of PTSD] follows the trauma with a latency, which may range from a few weeks to months (but rarely exceeds 6mths ) DSM-IV subclassi \201 cation: 1 \200\2233mths (acute); >3mths (chronic), and onset after 6mths (delayed) Delayed onset is uncommon; delayed reporting is more common. 1 http://www.who.int/classi \201 cations/icd/en/WHO (1992). 13_Smedley_Chap13.indd 312 1/2/2013 1:34:25 PM POST-TRAUMATIC STRESS DISORDER 1: DIAGNOSIS 313 Assessment \200 Victims may be reluctant to admit to symptoms for fear of being seen as weak (especially military and emergency service personnel) Victims may \201 nd it too disturbing to talk about the event \200 Insensitive and prem ature assessment may lead to re-traumatization \200 Relatives \200\231 observations can b e helpful. In addition to clinical interview and mental state examination, there are standa rdized psychiatric measures: \200 Clinician Administered Assessment Scale for PTSD (CAPS) : highly structured interview gives a measure of lifetime and current PTSD severity and functional i mpairment. Regarded as the gold standard \200 Impact of Event Scale \200\223Revised (IES \200\223R): a 22-item self-report scale, which assesses frequency of the core symptoms; int rusive phenomena (e.g. \202 ashbacks), avoidance, and hyperarousal (not diagnostic measur e) \200 Davidson Trauma Scale (DTS): a 17-item self-report scale that provides a measure of the severity and frequency of each DSM-IV symptom. Risk factors for PTSD No single event will cause PTSD in all exposed individuals. Risk fact ors include the following: \200 Pre-trauma factors: anxious personality \200 previous and/or familial psychiatric history \200 lower educat ion and sociocultural status \200 genetic predisposition, i concordance in monozygotes \200 female gender, except among the military \200 younger age, especially in males Concurrent life stressors \200 Trauma and peritraumatic factors: severity \200\224generally, there is a dose \200\223response curve \200 physical injury \200\224the meaning of an injury is as important as its objective severity (perceived) threat of serious injury or to life (of self and/or others) \200 dissociation \200\224depersonalization, derealization \200 extended exposure, such as being taken ho stage and being trapped \200 elevated autonomic arousal, especially heart rate. Post-trauma factors: adverse reactions of others: criticism, rejection, blame \200 2 life stressors \200 l ack of support. Occupations at risk Sectors likely to expose employees to work-related trauma. \200 Milit ary \200 Heavy industry \200 Emergency services \200 Offshore oil and gas industry \200 Construction \200 Sea \201 shing \200 Farming. 13_Smedley_Chap13.indd 313 1/2/2013 1:34:25 PM CHAPTER 13 Psychiatric disorders 314 Post-traumatic stress disorder 2: management The National Institute for Health and Clinical Excellence (NICE) has pub- lished guidelines on the management of PTSD. \200 Psychologic al \201 rst aid is a widely agreed paradigm for helping individuals and communities after major calamity, including: \200 attending to basic needs for food, safety, etc. \200 o utreach and dissemination of information \200 strengthening community, social, and family structures \200 psycho-education \200\224normal reactions and coping methods \200 tri age \200\224identify those requiring psychiatric care Watchful waiting: . most individuals do not develop PTSD; thus do not subject all victims to psychiatric treatment or even counseling. Instead, monitor progress and provide treatment for those whose symptoms last 7 1mth Facilitate peer, family, and community support \200 Critical incident stress debrie \201 ng (CISD): mandatory debriefs should not be conducted \200 single-session debriefs are neutral or oc casionally harmful. Formal treatments PTSD mostly occurs in the context of comorbidity, especially depression, anxiety, and alcohol abuse. The NICE guidelines endorse the following treatments: \200 Ps ychological therapies should be tried \201 rst: trauma-focused cognitive behavioral therapy (TFCBT) \200 eye movement desensitization and reprocessing (EMDR) Pharmacotherapy: paroxetine and mirtazapine for general use \200 amitriptyline hydrochloride and phenelzin e for specialist use \200 Medication is appropriate if the patient has not responded to T FCBT or EMDR, or is unwilling and/or unable to undergo such psychotherapy Patients should be advised of side effects and discontinuation/ withdrawal symptoms (particularly paroxetine) A hypnotic may be used in the short term for sleep problems \200 Antidepressants are pref erred for chronic sleep dif \201 culties to avoid dependence Propranolol and hydrocortisone may have psychoprophylactic properties, but routine use cannot be justi \201 ed. Prognosis \200 Most spontaneous recovery is within the \201 rst few weeks \200 There may be a re-emergence of symptoms 12mths after the event \200\224the anniversary reaction If persistent or recurrent after 12mths, symptoms may run a lengthy chronic course. 13_Smedley_Chap13.indd 314 1/2/2013 1:34:25 PM POST-TRAUMATIC STRESS DISORDER 2: MANAGEMENT 315 PTSD and the law \200 Civil proceedings: concerns about feigning and exaggeration of PTSD symptoms are common, but evidence suggests that this is not a widespread problem. Symptoms tend not to remit after claim settlement Criminal proceedings: PTSD can mitigate or explain the conduct of the accused. However, mer ely suffering from PTSD does not mean that there is any causal connection between the indiv idual \200\231s mental state and the alleged offense False vs. genuine claimants: rigorous assessment is essential and should include: \200 clinical interview \200 standardized measures \200 GP and hospital reco rds \200 information from others (e.g. spouse). Distinguishing false from genuine symptoms Genuine claimants display consistent accounts ac ross different settings and at different times. Caution should be exercised when individual s do not describe their symptoms and experiences in spontaneous and lay terms. Pseudo-techn ical language may suggest coaching. In most genuine cases, descriptions of dramatic events are accompanied by appropriate emo- tional displays (e.g. distress, disgust, anxiety). Repo rting of symptoms (e.g. hallucinations and delusions), rarely associated with PTSD, should raise suspicion, as should the reporting of unremitting symptoms: PTSD is a phasic conditio n with spells of remission and relapse. Genuine claimants do not tend to be uncooperative o r suspicious of the examiner. Most genuine claimants minimize their suffering and distress, and do not blame all their dif \201 culties on PTSD. Further information National Institute for Health and Clinical Excellence (2005). Post-trau matic stress disorder. the management of PTSD in adults and children in primary and seconda ry care. Royal College of Psychiatrists, London/British Psychological Society, Leicester. A vailable at: M http://www.nice. org.uk/CG26 Meze G (2006). Post-traumatic stress disorder and the law. Psychiatry, 5 , 243 \200\2237. K lein S, Alexander DA (2009). Epidemiology and presentation of post-traumatic disorders. Psychiatry , 8(8), 282 \200\2237. Klein S, Alexander DA (2011). The impact of trauma within organizations. In: Tehrani N., ed ., Managing trauma in the workplace , pp. 117 \200\22338. Routledge, Abingdon. 13_Smedley_Chap13.indd 315 1/2/2013 1:34:25 PM This page intentionally left blank 317 Chapter 14 Reproductive disorders Impaired fertility 318 Adverse pregnancy outcomes 320 Gynaecomastia 322 14_Smedley_Chap14.indd 317 1/2/2013 12:22:19 PM CHAPTER 14 Reproductive disorders 318 Impaired fertility Infertility is de \201 ned as a failure to conceive after 12mths of att empting to conceive: \200 Many factors which can lead to delayed time to pregnancy are no t due to reduced fecundity Occupational factors which may interfere with reproduction by reducing the opportunity for sexual intercourse include: \200 shift working \200 long w orking hours \200 prolonged absences from home Relatively few occupational exposures have been associated with impaired fertility and usua lly only in the most exposed. Improved workplace control measures mean that some exposures, such as anesthetic gasses (when used without a scavenging system), are only of historical interest in this regard Some have linked environmental oestrogens (PCBs, phthalates, dioxin, etc.) to recent reductions in male sperm counts. Epidemiology \200 Infertility now affects 7 15% of couples in developed countries and has almost doubled in the last 20yrs The ratio of 5 to 4 causes of infertility is approximately 2:1 \200 One dif \201 culty i n identifying occupational risk factors is that only a proportion of workers are seeking to conceive at any given time. Therefore detecting reproductive hazards can be dif \201 cult As sensitive pregnancy tests have become available, it has become apparent that a signi \201 cant proportion of conceptions do not lead to successful pregna ncy. Clinical factors Males \200 Azoospermia: no detectable spermatozoa \200 Low sperm count \200 Reduced or absent libido. Females \200 Anovulation \200 Reduced or absent libid o \200 Implantation failure \200 Abortion. Causal exposures The following have been associated with reduced fecundity in those exposed in an occupational setting. Evidence is usually based on cross- sectional surveys and case -control studies. \200 Metals: \200 lead \200 mercury \200 chromium 14_Smedley_Chap14.indd 318 1/2/2013 12:22:20 PM IMPAIRED FERTILITY 319 Pesticides: dibromochloropropane (DBCP), carbaryl \200 Organic solvents: carbon disulphid e, glycol ethers \200 Anesthetic gasses \200 Sex hormones \200 Ionizing and non-ioniz ing radiation \200 Heat stress. Industries at risk \200 Chemical industry \200 Lead smelting \200 Farming \200 Indu strial painting. Clinical assessment and diagnosis \200 Reproductive history: establish whether either par tner has previously had children to distinguish primary infertility from secondary infertil ity Con \201 rm that the couple are sexually active (shift work, overseas postings, etc.) and that the woman is menstruating The occupational history should focus on work with known reproductive hazards, taking into account likely exposure intensity It may be dif \201 cult to establish whether workplace factors are responsible for delayed conception, although in 4 an improved sperm count on exposure reduc tion would support an occupational etiology 4 Semen analyzes should be done on two samples \200 5 Menstruation suggests ovulation, bu t check mid-luteal (day 22 \200\22326) serum progesterone Referral to an infertility clinic for further investigation \200 Hysterosalpingogram or d iagnostic laparoscopy \200 Ultrasound to con \201 rm ovulation may be useful. Prognosis Depends on cause. Withdrawal from exposure may allow recovery in some cases. Health surveillance None. Medical management \200 Women contemplating pregnancy may seek advice from an OH professional Many couples \201 nding dif \201 culty in conceiving will do so within 12mths of presentation without intervention Age and family history of early menopause may dictate early investigation \200 Assisted r eproduction may be necessary in some cases. Relevant legislation \200 HSE (2002). Control of Lead at Work Regulations , 3rd edn. Appr oved Code of Practice and Guidance , L132. HSE Books, Sudbury. HSE (1999). Ionizing Radiation Regulations 1999. Approved Code of Practice and Guidance , L121. HSE Books, Sudbury. 14_Smedley_Chap14.indd 319 1/2/2013 12:22:20 PM CHAPTER 14 Reproductive disorders 320 Adverse pregnancy outcomes Adverse pregnancy outcomes include: \200 Spontaneous abortion \200 Low birth weight (<2500g) \200 Pre-term delivery (<37wks gestation) \200 Birth d efects. Epidemiology \200 Over half of pregnant women are in paid employment \200 15% of pregna ncies end in a spontaneous miscarriage \200 60% of congenital malformations have no ident i \201 ed cause \200 Attention has focused on maternal factors, but paternal pre-concept ual exposures may be relevant. Further studies are required \200 A large number of studies ha ve examined occupations and occupational exposures and pregnancy outcomes. Causal exposures Chemical hazards \200 Metals: \200 lead \200 mercury \200 Organic solvents \200 Pesticides? Physical hazards \200 Lifting \200 Heavy physical work \200 Prolonged standing \200 Ionizing radiation \200 Heat \200 Physical violence. Bi ological hazards Infections: \200 Rubella \200 Toxoplasma \200 Chlamydia psittaci (en zootic abortion) \200 Coxiella burnetti (Q fever) \200 Parvovirus B19 ( \201 fth disea se). Industries at risk Several industries have been associated with adverse pregnancy outcomes but the evidence is inconsistent. Industries implicated include: \200 Agriculture \200 Healthcare \200 Painting \200 Printing \200 Fire \201 ghting 14_Smedley_Chap14.indd 320 1/2/2013 12:22:20 PM ADVERSE PREGNANCY OUTCOMES 321 Security services (risk of violence): police \200 prison service. Health surveillance None appropriate. Medical management The issue of adverse pregnancy outcomes may arise when an employee is pr egnant, and the question is asked whether it is safe for her to continue her current role. This is a dif \201 cult area as an anxious worker \200\231s fears may be realized even whe re there is no association between her work and adverse pregnancy outcomes. For many work e xposures there is insuf- \201 cient evidence to offer de \201 nitive advice regarding th e likely risks. HSE advises against a number of work activities during pregnancy: Diving \200 Work at pressure \200 Lead (Pb) work \200 Preparation of cytotoxic drugs. Evidence-based guidelines on \200\230Physical and shift work in pregnancy \200\231 found consistent evidence for some adverse pregnancy outcomes in relation to prolonged standing, heavy lifting, and prolonged hours (>40h), but the risk was low. On precautionary grounds t hey advised employers should reduce pregnant workers \200\231 exposure to prolonged standin g, heavy physical work, and lifting. Measures to control exposures should be taken for women potentially exposed to ionizing rad iation or hazardous chemicals. If adequate control cannot be achieved, the pregnant worker should be allocated alternative duties or, if this is not possible, should be suspended fro m work. Note that as pregnancy progresses the hazards may change (e.g. ergonomic factors in of \201 ce workers) and the risk assessment should be kept under regu- lar review (see b p. 524, New and expectant mothers and b p. 557, Employment law). Relevant legislation and guidance \200 HSE (1999). Management of Health and Safety at Wor k Regulations 1999 . Available at: M http://www.hse.gov.uk/pubns/books/l21.htm \200 HSE ( 2002). New and expectant mothers at work , 2nd edn. HSE Books, Sudbury. NHS Plus, Royal College of Physicians, Faculty of Occupational Medicine. (2009). Physical and shift work in pregnancy: occupational aspects of management. A national guideline . RCP, London. 14_Smedley_Chap14.indd 321 1/2/2013 12:22:20 PM CHAPTER 14 Reproductive disorders 322 Gynaecomastia \200 Gynaecomastia is the most common benign breast condition in men \200 Breast enlargement may be painless or associated with discomfort \200 Galactorrhoea may also occur. Epidemiology \200 The most common causes of gynaecomastia are puberty, obesity, and drugs, including anabolic steroid abuse, and medication for HIV Rarely, gynaecomastia in 4 may be due to breast cancer \200 Gynaecomastia is present in u p to a third of adolescent 4 . Clinical features Gynaecomastia may be bilateral or unilateral. Causal exposures \200 Gynaecomastia: female sex hormone manufacture \200 anabolic steroids (bodybuilders) Pseudo-gynaecomastia: obesity \200 work requiring repetitive force on chest (rare). Industries at risk \200 Pharmaceutical industry. Sex hormone manufacture \200 Professio nal sports especially \200\230power \200\231 sports where misuse of anabolic steroids may be prevalent. Clinical assessment and diagnosis Palpable gynaecomastia is common in otherwise healthy mal es but the palpable breast tissue is generally <5cm in diameter. Prognosis Most cases settle with withdrawal from exposure. Health surveillance Periodic medical examination is indicated where pharmaceutical workers may be exposed to sex hormones despite workplace control measures. Medical management \200 If occupationally acquired withdraw from exposure \200 If gynae comastia fails to settle following withdrawal from exposure to drugs, surgery may be necessary. 14_Smedley_Chap14.indd 322 1/2/2013 12:22:20 PM 323 Chapter 15 Hematological disorders Bone marrow aplasia 324 Anemia 326 Methaemoglobinaemia 328 Haemolysis 329 Hematological mal ignancies 330 15_Smedley_Chap15.indd 323 1/2/2013 12:24:04 PM CHAPTER 15 Hematological disorders 324 Bone marrow aplasia Causal exposures/industries \200 Ionizing radiation: acute (usually a ccidental) exposure to a dose of ionizing radiation above 7 0.2Sv produces marrow hypoplasia/aplasia as a deterministic (dos e-related) effect. \200 nuclear industry \200 medical radiography and nuclear medicine \200 industrial radiography Benzene: chronic exposure above approximately 50ppm produces a range of haematotoxic effects including marrow suppression. \200 rubber and shoe industri es \200 plastics production \200 explosives production \200 motor vehicle repair. Clinical features Haematopoietic stem cell hypoplasia leads to peripheral blood cytopenias. The clinical features vary according to the severity of stem cell suppres- sion, and the c ell lines that are affected (erythrocytes, leucocytes, and platelets), but include combinat ions of: \200 Anemia: \200 fatigue \200 dyspnoea Neutropenia/lymphopenia: i incidence of bacterial infections \200 Thrombocytopenia: petechiae and ecchymoses \200 gingival bleeding \200 i risk of serious bleeds, e.g. ren al or GI. Radiation exposure \200 Following acute exposures, the peripheral blood lymphocyte count falls within 24 \200\22348h (because of rapid cell death). Other cell lines are not destroy ed immediately. Although unable to divide, damaged neutrophils and platelets can survive fo r up to 2 \200\2233wks, and red cells for up to 100 days. Therefore, there is a delay of 1 \200\2233wks before pancytopenia develops because of failure of replacement from marrow ste m cells Treatment for victims of serious exposures is intensive multi-system support, transfusions of red cells and platelets, and management of acute infection with appropriate antibiotics. In severe cases, erythropoietin and colony-stimulating factors (e.g. granulocyte-colony st imulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF)) are us ed to facilitate stem cell function. Bone marrow transplantation is possible, but the succe ss rate is very low Prognosis depends on the dose: dose of (cid:3) 1Sv has a fatality rate of at least 10%; at <1Sv recovery from a nadir in peripheral blood counts at 4 \200\2236wks is usual. Normal blood counts re- established 2 \200\2233mths after the exposure incident \200 dose of 3 \200\2234Sv has a 50% fatality rate at 30 days post-exposure. 15_Smedley_Chap15.indd 324 1/2/2013 12:24:04 PM BONE MARROW APLASIA 325 Prevention Prevention is through fastidious regulatory control of exposure, includ- ing con trol of the working environment and work practices, and work- place exposure limits (see b p. 22, Ionizing radiation 4: exposure control; b p. 542, Ionizing Radiation Regulations 199 9). Health surveillance \200 Ionizing radiation: \200\230classi \201 ed \200\231 worker s under the Ionizing Radiation Regulations (personal exposure >6mSv or 3/10ths of any other exposure limit) require baseline medical assessment plus periodic reviews (usually annual) of dosimetry results and sickness absence records (see b p. 542, Ionizing Radiation Regula tions). Benzene: appropriate health surveillance for benzene would be a health record, as described in the COSHH Regulations. Routine periodic screening of hematological indices is probably inappropriate with adequate risk controls. Relevant legislation \200 The following are reportable under RIDDOR: blood dyscrasias that are attributable to ionizing radiation \200 benzene poisoning radia tion accident. The approved dosimetry service should be informed in the event of a 15_Smedley_Chap15.indd 325 1/2/2013 12:24:04 PM CHAPTER 15 Hematological disorders 326 Anemia Anemia can be caused by a number of (acute or chronic) occupational exposures, and b y a number of different mechanisms including impairment of haem synthesis, marrow suppressi on, and haemolysis. Marrow suppres- sion and haemolysis are covered separately in b p. 324, Bone marrow aplasia and b p. 329, Haemolysis. Impaired hemoglobin synthesis Exposures/industries \200 Lead is the classical occupationa l exposure associated with impaired hemoglobin synthesis Industries: lead smelting \200 battery manufacture \200 demolition \200 glass making. Mechanism Lead, through its high af \201 nity for binding to sulphydryl groups, inhibits i mportant enzymes in the haem synthesis pathway (see Fig. 15.1). Clinical features \200 Mi ld anemia, which may play little or no part in the fatigue that is commonly associated with lead poisoning Associated features include palsies due to peripheral neuropathy, arthralgia, and (rarely) confusion due to encephalopathy The characteristic \201 nding on investigation is basophilic stippling of erythrocytes on a peripheral blood \201 lm Blood lead levels >80 g/dL. Prevention Prevention is by substitution and exposure control (see b p. 538, Control of Lea d at Work Regulations 2002). Health surveillance Statutory surveillance includes baseline a nd periodic screening (intervals are speci \201 ed by individual susceptibility (e.g. wome n and young peo- ple) and exposure level). For health surveillance for inorganic lead, see b p. 434, Inorganic lead. Compensation Anemia with hemoglobin (cid:4) 9g/dL and a blood \201 lm showing punctate basophilia is prescribed (C1(a)) for Industrial Injuries Disableme nt Bene \201 t in those who are exposed to lead. Relevant legislation Lead poisoning is re portable under RIDDOR. 15_Smedley_Chap15.indd 326 1/2/2013 12:24:04 PM anemia 327 Mitochondrion Cytosol Glycine+succinyl CoA ALA synthetase \200\223ve feedback 5-Aminolaevulinic acid (ALA) ALA dehydratase Porphobilinogen (PBG) Haem PBG deaminase Ferrochelatase Uroporphyrinogen cosynthetase Protoporphyrin IX Protoporphyrinogen oxidase Uroporphyrinogen III Uroporphyrinogen decarboxylase Protoporphyrinogen Coproporphyrinogen oxidase Coproporphyrinogen Enzymes inhibited by lead Enzymes Fig. 15.1 Haem synthesis. 15_Smedley_Chap15.indd 327 1/2/2013 12:24:04 PM CHAPTER 15 Hematological disorders 328 Methaemoglobinaemia Methaemoglobinaemia arises when the ferrous iron moiety in haem is oxi- dized into the ferric form. The consequence is a decreased oxygen-carrying capacity of hem oglobin. It can be caused by a number of acute occupa- tional exposures. Causative agents \200 Ferricyanide \200 Bivalent copper \200 Chromates \200 Chlorat es \200 Quinones \200 Dyes with a high oxidation \200\223reduction potential \200 Nit rite, often used as a preservative, is one of the most common methaemoglobin-forming agents Aniline dye derivatives. Clinical features \200 Cyanosis \200 Dyspnoea \200 Headaches and dizziness \200 Mus cle weakness \200 Peripheral blood \201 lm shows mild anemia and erythrocyte abnormalit ies (Heinz bodies and punctate polychromasia). Individual susceptibility Hereditary methaemoglobin reductase de \201 ciency. Treatment Ac ute treatment is with methylene blue (methylthioninium chloride), administered by slow IV i nfusion. Management of acute poisoning is cov- ered in detail on b p. 808, Methaemoglobinae mia (acute treatment). (cid:2) Methylthioninium chloride may cause brisk haemolysis in thos e with glucose-6-phosphate dehydrogenase (G6PD) de \201 ciency. Relevant legislation Acute poisoning with a nitro-, chloro-, or amino- derivative of benzen e is reportable under RIDDOR . 15_Smedley_Chap15.indd 328 1/2/2013 12:24:05 PM HAEMOLYSIS 329 Haemolysis Haemolysis is the process of premature red blood cell destruction. Clinical features and treatment \200 Acute: haemoglobinuria, jaundice, and abdominal pain \200 methaemoglobinaemia and methaemoglobin uria \200 complicated by anuric renal failure \200 exchange blood transfusion is life-s aving in severe cases Chronic: anemia \200 reticulocytosis due to i red cell production is the hallmark of haemolysis. Exposures \200 Arsine gas: industries \200\224micro-electronics industry (semiconductor manufacture), metal smelting, plating, galvanizing, and soldering \200 effects occur with acute poisoning at exposures >3ppm for several hours, or >20ppm for <1h chronic low-level exposure can cause anemia with mild i bilirubin \200 diagnosis is based on history of exposure and i urinary arsenic Naphthalene: industries \200\224manufacture of plastics and dyestuffs, mothballs, biocides for the wood industry can precipitate haemolysis in individuals with G6PD de \201 ciency Rare occupational exposures associated with haemolysis include: potassium chlorate \200 pyrogallic acid \200 stibine gas (rare accidental exposure). Prevention Prevention is by substitution and exposure control. 15_Smedley_Chap15.indd 329 1/2/2013 12:24:05 PM CHAPTER 15 Hematological disorders 330 Hematological malignancies Leukaemias Exposures Two exposures have a well-established assoc iation with leukemia. \200 Ionizing radiation: leukaemogenesis is a late stochastic effec t of ionizing radiation (no dose threshold for the effect). The following have been noted i n excess among radiation workers: \200 acute myeloid leukemia (AML) \200 acute lymphobl astic leukemia (ALL) \200 chronic myeloid leukemia (CML) Benzene: AML. Other exposures (or job/industry used as a marker, but with the exact exposur e unclear) have been implicated with small increases in leukemia risk. Most studies have be en small, and in many there is a problem with confounding by benzene exposure. \200 Possi ble i leukemia risk: \200 1,3-butadiene \200 ethylene oxide. Clinical features Presents with a combination of anemia, bleeding, and infection. Compensat ion Acute non-lymphatic leukemia is prescribed (C7) for Industrial Injuries Disablement Ben e \201 t in those who are exposed to benzene. Lymphoproliferative disorders Exposures \200 Ionizing radiation: the following have been noted in excess among radiation workers, and are late stochastic effects: \200 multiple myeloma \200 non-Hodg kin \200\231s lymphoma. Clinical features Presents with anemia or local mass. Treatment and prognosis of hematologi cal malignancies Treatment is complex and beyond the scope of this book. However, the usual approach includes chemotherapy regimes +/ \200\223 radiotherapy +/ \200\223 bone marrow tr ansplant. The prognosis for treated acute leukaemias has improved signi \201 cantly in the past 10yrs. Prevention Prevention is through exposure control. See b p. 542, Ionizing Radi ation Regulations 1999. 15_Smedley_Chap15.indd 330 1/2/2013 12:24:05 PM 331 Chapter 16 Medically unexplained occupational disorders Post-con \202 ict illness in military personnel 332 Sick building syndrome 334 Karoshi : d eath from overwork 336 16_Smedley_Chap16.indd 331 1/2/2013 12:25:33 PM CHAPTER 16 Medically unexplained occupational 332 Post-con \202 ict illness in military personnel In the aftermath of every major con \202 ict over the past century, some returning personnel have complained of ill health. Some hav e symptoms of physical origin, others psychiatric disorder including post-traumatic stress disorder (PTSD). However, there is a third group characterized by vague and non-speci \201 c symptoms, for which (despite extensive investigation) no cause is found. Different names have been ascribed to this third group, including Agent Orange syndrome and Gulf War illne ss. These syndromes share many common features. There are also similarities with other medi - cally unexplained symptoms, including chronic fatigue syndrome, multiple chemical sensiti vity syndrome and neurasthenia. All groups have de \201 nitive health care needs. Gulf War illness Gulf War illness affecting the veterans of the Arabian Gulf Con \202 ict of 1991 has been extensively investigated, with over $300 million of funds from the US and UK governments. Despite extensive study into possible links with vaccinations, depleted ura nium exposure, oil well \201 res, and exposure to pesticides or other chemical agents; no de \201 nitive cause has been found. However, the following lessons have emerged, and are pertinent to other post-deployment conditions: \200 In general, military populations are healthier than civilians \200\224the healthy warrior effect More than a decade after deployment, some Gulf War veterans still suffer ill health. However, the same symptoms and groupings are seen in non-Gulf Veterans c ontrol groups. There appears to be no unique Gulf War syndrome Although the condition persists two decades after exposure and many veterans remain ill, in general they appear to be getting better gradually Gulf veterans are 2 or 3 times more likely to have symptom complexes including multi-focal pain, fatigue, cognitive or memory problems, and psychologi cal distress. Most of these individuals do not meet criteria for established psychiatric il lness Although there is a raised incidence of PTSD in Gulf War veterans as in other con \202 ict s, it is not elevated to the degree that could explain the overall increase in ill health. Common symptoms include tiredness, headaches, lack of concentration, memory loss, and numbn ess \200 Thorough medical examination including physical, physiological, and psychological testing have revealed no major abnormalities Reported health is worse the lower the rank and after retirement \200 In contrast to cont rol groups, Gulf War veterans report more of every hazard and recall exposure to more of th ese over time. Those who are in good health recall fewer exposures There is no evidence of an excess of malignancy, birth defects, or increased mortality. 16_Smedley_Chap16.indd 332 1/2/2013 12:25:33 PM POST-CONFLICT ILLNESS IN MILITARY PERSONNEL 333 Management of post-con \202 ict illness \200 A detailed history, examination, and invest igation should be taken