Neurological Deficits After Long-term Pyrethroid Exposure.

Pyrethroid pesticides have been suggested to be a cause of Parkinson disease and other neurodegenerative diseases. To investigate this, a cross-sectional study was conducted among 120 Bolivian public health vector program spray men, primarily exposed to pyrethroids. Pesticide exposure and central nervous system (CNS) symptoms were determined by a structured interview, whereas neuromotor and neurocognitive performance was assessed using the computerized Behavioral Assessment and Research System and CATSYS system. Individuals exposed to higher levels reported significantly more CNS symptoms (adjusted odds ratio per quintile of cumulative exposure = 2.01 [1.22-3.31]). There was no association seen between pyrethroid exposure and neuromotor performance. Higher spraying intensity was associated with significantly worse neurocognitive performance in structural equation models (adjusted ß per quintile = -0.405 [-0.660 to -0.150]), and workers only exposed to pyrethroids performed worse than workers also exposed to other pesticides (adjusted ß = -1.344 [-2.224 to -0.464]). Chronic pyrethroid exposure may cause deterioration in neurocognitive performance, and exposure control is recommended.

Selection bias in follow-up interviews with individuals attending the emergency department for occupational injuries.

OBJECTIVE: To examine whether supplementary interview participation was comparable for occupationally injured patients attending two hospital emergency departments and to investigate the magnitude of selection bias in relation to sex, age, severity, job tasks and industry risk level. METHODS: Workers aged 18-70 years who contacted the two emergency departments for an acute occupational injury in 2013 were eligible and given a short questionnaire. Following written consent, a semi-structured interview concerning health and transient risk factors was conducted by telephone. The two departments were compared for study recruitment by age and sex. Respondents and non-respondents to the interview were compared for age, sex, injury severity, job tasks and industry risk level. RESULTS: Of 4002 patients attending the two hospitals, 1693 (42%) participated in the interview. One hospital had a markedly higher response rate to the questionnaire, but the proportions of participation in the interview were similar in the two hospitals. Patients aged <30 years were over-represented among non-respondents whereas sex, injury severity, job task and industry risk level were not significantly different between respondents and non-respondents. CONCLUSIONS: Despite a relatively low interview participation rate among injured individuals attending the emergency department, selection bias was limited. This indicates that results regarding injury risk patterns may be more widely generalisable when examining the causality of occupational injuries. However, the study also showed that young injured workers were less likely to participate in follow-up interviews, which is an important factor when interpreting age-related risk of injury.

Work injuries among migrant workers in Denmark.

OBJECTIVES: Work migration into Denmark has increased during the recent decades, especially after the enlargement of the European Union (EU) in 2004. Whether or not migrant workers experience more work injuries than the native workforce has been debated and results are conflicting, most likely due to methodological difficulties and cultural disparities. We set out to meet these challenges using population-based work injury registers, targeting a specific and representative region in Denmark. METHODS: This population-based study used data on work injuries from an emergency department (ED) and reported injuries from the ED's catchment area to the Danish Working Environment Authority during 11 years. We calculated incidences of work injury for groups of migrant workers compared with native Danes and adjusted incidence rate ratios based on information on the complete working population. RESULTS: The incidences of work injuries among migrant workers from the new EU countries and from the rest of the world were higher compared with Danish workers and workers from the old EU countries and other Western countries. Especially migrants older than 30 years and in low-risk industries were at higher risk. Workers who had migrated recently were at even higher risk. CONCLUSIONS: We found increased risk of work injuries among migrant workers. Studying migrants in registers is a methodological challenge as some migrants are not registered, for legal or illegal reasons; thus, only a selected group is studied, but this may most likely underestimate the risk.

Transient risk factors of acute occupational injuries: a case-crossover study in two Danish emergency departments.

Objectives The objectives of this study were to (i) identify transient risk factors of occupational injuries and (ii) determine if the risk varies with age, injury severity, job task, and industry risk level. Method A case-crossover design was used to examine the effect of seven specific transient risk factors (time pressure, disagreement with someone, feeling sick, being distracted by someone, non-routine task, altered surroundings, and broken machinery and materials) for occupational injuries. In the study, 1693 patients with occupational injuries were recruited from a total of 4002 occupational injuries seen in 2013 at two emergency departments in Denmark. Effect estimates were calculated using the matched-pair interval approach. Results Increased risk for an occupational injury was found for time pressure [odds ratio (OR) 1.6, 95% confidence interval (95% CI) 1.3-2.0], feeling sick (OR 2.7, 95% CI 1.9-3.9), being distracted by someone (OR 3.1, 95% CI 2.3-4.1), non-routine task (OR 8.2, 95% CI 5.3-12.5), altered surroundings (OR 20.9, 95% CI 12.2-35.8), and broken machinery or materials (OR 20.6, 95% CI 13.5-31.7). The risk of occupational injury did not vary substantially in relation to sex, age, job task, industry risk level, or injury severity. Conclusion Use of a case-crossover design identified several worker-related transient risk factors (time pressure, feeling sick, being distracted by someone) that led to significantly increased risks for occupational injuries. In particular, equipment (broken machinery or materials) and work-practice-related factors (non-routine task and altered surroundings) increased the risk of an occupational injury. Elaboration of results in relation to hazard period and information bias is warranted.

Impact of Training Bolivian Farmers on Integrated Pest Management and Diffusion of Knowledge to Neighboring Farmers.

Teaching farmers integrated pest management (IPM) in farmer field schools (FFS) has led to reduced pesticide use and safer handling. This article evaluates the long-term impact of training farmers on IPM and the diffusion of knowledge from trained farmers to neighboring farmers, a subject of importance to justify training costs and to promote a healthy and sustainable agriculture. Training on IPM of farmers took place from 2002 to 2004 in their villages in La Paz County, Bolivia, whereas dissemination of knowledge from trained farmer to neighboring farmer took place until 2009. To evaluate the impact of the intervention, self-reported knowledge and practice on pesticide handling and IPM among trained farmers (n = 23) and their neighboring farmers (n = 47) were analyzed in a follow-up study and compared in a cross-sectional analysis with a control group of farmers (n = 138) introduced in 2009. Variables were analyzed using χ2 test and analysis of variance (ANOVA). Trained farmers improved and performed significantly better in all tested variables than their neighboring farmers, although the latter also improved their performance from 2002 to 2009. Including a control group showed an increasing trend in all variables, with the control farmers having the poorest performance and trained farmers the best. The same was seen in an aggregated variable where trained farmers had a mean score of 16.55 (95% confidence interval [CI]: 15.45-17.65), neighboring farmers a mean score of 11.97 (95% CI: 10.56-13.38), and control farmers a mean score of 9.18 (95% CI: 8.55-9.80). Controlling for age and living altitude did not change these results. Trained farmers and their neighboring farmers improved and maintained knowledge and practice on IPM and pesticide handling. Diffusion of knowledge from trained farmers might explain the better performance of the neighboring farmers compared with the control farmers. Dissemination of knowledge can contribute to justify the cost and convince donors and governments in low-income countries to prioritize farmers training.

A case-crossover study of transient risk factors influence on occupational injuries: a study protocol based on a review of previous studies.

BACKGROUND: The occupational injury incident rate remains relatively high in the European Union. The case-crossover study gives a unique opportunity to study transient risk factors that normally would be very difficult to approach. Studies like this have been carried out in both America and Asia, but so far no relevant research has been conducted in Europe. METHOD: Case-crossover studies of occupational injuries were collected from PubMed and Embase and read through. Previous experiences concerning method, exposure and outcome, time-related measurements and construction of the questionnaire were taken into account in the preparation of a pilot study. Consequently, experiences from the pilot study were used to design the study protocol. Approximately 2000 patients with an occupational injury will be recruited from the emergency departments in Herning and Odense, Denmark. A standardised questionnaire will be used to collect basic demographic data and information on eight transient risk factors. Based on previous studies and knowledge on occupational injuries the transient risk factors we chose to examine were: time pressure, performing a task with a different method/using unaccustomed technique, change in working surroundings, using a phone, disagreement, feeling ill, being distracted and using malfunctioning machinery/tools or work material. Exposure time 'just before the injury' will be compared with two control periods, 'previous day at the same time of the injury' (pair match) and the previous work week (usual frequency). DISCUSSION: This study protocol describes a unique opportunity to calculate the effect of transient risk factors on occupational injuries in a European setting.

Is cumulated pyrethroid exposure associated with prediabetes? A cross-sectional study.

Pyrethroids are a class of insecticides used widely for vector control programs. Acute pyrethroid poisoning is rare, but well documented, whereas effects of cumulative exposure are insufficiently described, including possible negative effect on glucose regulation. The objective of this study was to investigate an association between exposure to pyrethroids and abnormal glucose regulation (prediabetes or diabetes). A cross-sectional study was performed among 116 pesticide sprayers from public vector control programs in Bolivia and 92 nonexposed controls. Pesticide exposure (duration, intensity, cumulative exposure) was assessed from questionnaire data. Participants were asked about symptoms of diabetes. Blood samples were analyzed for glycosylated hemoglobin (HbA1c), a measure of glucose regulation. No association was found between pyrethroid exposure and diabetes symptoms. The prevalence of abnormal glucose regulation (defined as HbA1c ≥ 5.6%) was 61.1% among sprayers and 7.9% among nonexposed controls, corresponding to an adjusted odds ratio (OR [95% confidence interval]) for all sprayers of 11.8 [4.2-33.2] and 18.5 [5.5-62.5] for pyrethroid-exposed only. Among sprayers who had only used pyrethroids, a significant positive trend was observed between cumulative pesticide exposure (total number of hours sprayed) and adjusted OR of abnormal glucose regulation, with OR 14.7 [0.9-235] in the third exposure quintile. The study found a severely increased prevalence of prediabetes among Bolivian pesticide sprayers compared with a control group, but the relevance of the control group is critical. Within the spraying group, an association between cumulative exposure to pyrethroids and abnormal glucose regulation was seen. Further studies are needed to confirm this association.

[Occupational asthma caused by maleic anhydride].

Organic acid anhydrides (OAA) are widely used in the chemical industry. They are irritants and can cause sensitization and asthma. We describe the first documented case of occupational asthma caused by the OAA maleic anhydride (MA) in the production of insecticides. A 60-year-old man developed work-related respiratory symptoms after eight years of intermittent exposure to MA. Peak expiratory flow measurements showed greater variance on work days than on days off. Both a basophilic activation test and determination of the MA-specific IgE level in serum showed sensitization to MA.

Do Bolivian small holder farmers improve and retain knowledge to reduce occupational pesticide poisonings after training on Integrated Pest Management?

BACKGROUND: Pesticide consumption is increasing in Bolivia as well as pest resistance, pesticide poisonings and pollution of the environment. This survey evaluates the training of small holder farmers on pesticide handling and ecological alternatives to reduce the negative pesticide effects. METHOD: A baseline survey was performed in 2002 and follow-up surveys in 2004 and 2009. Farmers were selected and trained on Integrated Pest Management (IPM) from 2002 to 2004 in Farmer Field Schools (FFS). After exclusions and drop outs, 23 FFS trained farmers could be compared to 47 neighbor farmers for changes in 'knowledge, attitude and practice' (KAP) on IPM and symptoms of poisoning when handling pesticides. Statistical analysis was performed with SPSS version 21.0 using χ2-test, Cochran's Q test and Student's T-test. RESULTS: Improvements were seen in both groups but most significant among the FFS farmers. At baseline no difference were seen between the two groups apart from a more frequent use of personal protection among the FFS farmers. After the training was finished significant differences were seen between FFS farmers and neighbor farmers on all KAP variables, a difference reduced to six of the KAP variables in 2009. No difference was seen in self-reported poisonings after pesticide handling. FFS farmers improved their KAP scores markedly during training and there after retained their knowledge, while neighbor farmers improved during the entire period. Ecological farming without the use of pesticides increased most among the FFS farmers. CONCLUSION: The study showed a sustained improvement among Farmers Field School trained farmers on personal protection and hygiene when handling pesticides, knowledge and use of IPM and ecological alternatives and a reduction in self-reported symptoms after pesticide handling. Similar though less pronounced improvements was seen among neighbor farmers having had less training and information on pesticide handling and alternatives than the FFS trained farmers. Training of farmers on IPM and good agricultural practices has positive effects, but is scarce in Bolivia as in most low-income countries and must be encouraged to support an improved and sustainable food production and to protect the health of farmers and consumers as well as the environment.

Patterns of work injuries: cases admitted to emergency room treatment compared to cases reported to the Danish Working Environment Authority during 2003-2010.

OBJECTIVE: To compare work injuries treated in an emergency department (ED) and injuries reported to the Danish Working Environment Authority (DWEA). METHODS: Work injuries of the ED, Odense University Hospital, and injuries from the geographical catchment area reported to the DWEA between 2003 and 2010 were included. The injuries included in both datasets were identified by merging the ED file and the DWEA file using the civil registry number and injury date information as key. RESULTS: Approximately 50 000 work injuries occurred in the catchment area of the ED. The intersection between the two injury registration systems was 16%. A major discordance concerned the type of injuries, as some injuries were seen frequently in the ED but not reported to the DWEA to any significant extent, for example 'eye injuries' and 'superficial lacerations or wounds'. On the other hand, some injuries are rarely seen in the ED, but often reported to the DWEA, for example 'low back pain'. Additionally, younger workers visit the ED more often than older workers, and injuries in the high risk sectors have the lowest reporting proportion. CONCLUSIONS: Neither the ED nor DWEA injury files alone give a complete picture of work injuries. But merged, they represent a significant number of injuries, taking into account differences in data sources, for example concerning uneven distribution of age, sex, type of injury and type of industry. Obviously, not all serious work related ED injuries resulting in lost work time are reported to the DWEA.

Social inequalities in childhood are predictors of unemployment in early adulthood.

INTRODUCTION: The aim of the present study was to establish if social inequalities in early childhood, particularly living in a socially and economically deprived neighbourhood, are predictive of later unemployment. MATERIAL AND METHODS: A cohort was established in 1987. It consists of 8-9 year-old children living in a socially deprived suburb who were followed in national registers for all categories of welfare benefits. The follow-up covered the period when participants were 21-27 years of age. A control group with the same age and gender distribution who were living in a neighbouring, relatively privileged middle class district were also followed for the purpose of comparison. RESULTS: The annual unemployment rate during the seven years of follow-up was significantly higher in the deprived neighbourhood group than in the middle class neighbourhood group, whereas long-term unemployment lasting more than two years did not differ significantly between the groups. Childhood background including a mother receiving social benefit was an independent factor associated with increased risk of later unemployment, whereas gender and single parenthood were not. CONCLUSION: The present findings suggest that socioeconomic disadvantage during childhood substantially increases the risk of unemployment in early adulthood, even during a follow-up period in the first decade of the 21st century when employment opportunities in Denmark were excellent. FUNDING: not relevant. TRIAL REGISTRATION: not relevant.

Parkinson's disease among gardeners exposed to pesticides--a Danish cohort study.

OBJECTIVE: Several studies have found positive associations between exposure to pesticides and Parkinson's disease. As Danish gardeners have had frequent, intensive exposure to pesticides, the aim of this study was to investigate their risk for Parkinson's disease. METHODS: The cohort was comprised of 3124 male members of the Danish Union of Gardeners on 1 April 1975. Hospital register data were used to follow them for a primary diagnosis of Parkinson's disease during 1977-2008 and to calculate standardized hospitalization rate ratios (SHR) for this disease among gardeners and the general Danish population for comparison. Data from the Danish Cancer Registry were used to calculate standardized incidence rate ratios (SIR) for smoking-related cancers among gardeners and the general population. RESULTS: The SHR for Parkinson's disease among gardeners was close to that of the general population [1.14, 95% confidence interval (95% CI) 0.76-1.65]. In a birth cohort analysis, a downward trend was observed, with the highest risk among gardeners born before 1915 (SHR 1.55, 95% CI 0.77-2.77). The SIR for smoking-related cancers did not differ from that of the general population. CONCLUSION: The results indicate a weak but dose-related association between exposure to pesticides and risk for Parkinson's disease; however, the results were based on 28 cases and the possibility of no association cannot be ruled out.

Can we enhance the ability to return to work among workers with stress-related disorders?

BACKGROUND: Stress-related disorders are widespread and responsible for high societal costs e.g. sick leave payment and reduced productivity. The aim of this study was to evaluate the effect of an intervention program on return to work or labour market. METHODS: In a controlled interventional study design we compared 72 emotionally distressed patients, who received support during 2006, with 89 control individuals who had also been sick listed for emotional distress. Intervention was provided by trained psychologists and social workers who were in continuous dialog with the patients, providing counselling e.g. on decisions concerning resumption of work, support to families, participation in meetings with the workplace. Basically, the controls and the intervention group share the same access to welfare benefits. The main outcome was time to return to labour market (TTR). RESULTS: The baseline characteristics were similar in the two groups. There were no differences in the rate of resuming work between the two groups. About 80% in both groups had returned to the labour market after one year. CONCLUSION: An intervention program with psychological stress management and case management did not improve work capability compared to usual care. Work resumption as a single outcome probably is an insensitive parameter of intervention management quality, and should be supplemented by other data on different aspects of treatment.

Genetic Alterations in Pesticide Exposed Bolivian Farmers: An evaluation by analysis of chromosomal aberrations and the comet assay.

BACKGROUND: Pesticides are of concern in Bolivia because of increasing use. Frequent intoxications have been demonstrated due to use of very toxic pesticides, insufficient control of distribution and sale and little knowledge among farmers of protective measures and hygienic procedures. METHOD: Questionnaires were applied and blood tests taken from 81 volunteers from La Paz County, of whom 48 were pesticide exposed farmers and 33 non-exposed controls. Sixty males and 21 females participated with a mean age of 37.3 years (range 17-76). Data of exposure and possible genetic damage were collected and evaluated by well known statistical methods, controlling for relevant confounders. To measure genetic damage chromosomal aberrations and the comet assay analysis were performed. RESULTS: Pesticide exposed farmers had a higher degree of genetic damage compared to the control group. The number of chromosomal aberrations increased with the intensity of pesticide exposure. Females had a lower number of chromosomal aberrations than males, and people living at altitudes above 2500 metres seemed to exhibit more DNA damage measured by the comet assay. CONCLUSIONS: Bolivian farmers showed signs of genotoxic damage, probably related to exposure to pesticides. Due to the potentially negative long term health effects of genetic damage on reproduction and the development of cancer, preventive measures are recommended. Effective control with imports and sales, banning of the most toxic pesticides, education and information are possible measures, which could help preventing the negative effects of pesticides on human health and the environment.

Time trends in cancer risk and pesticide exposure, a long-term follow-up of Danish gardeners.

OBJECTIVES: Occupational exposure to petrochemical pesticides was high during the first 10-15 years after their introduction in the late 1940s, and, during these years, many cases of intoxication occurred. In the 1960s, the use and marketing of pesticides was regulated to reduce exposure to these substances, and, since 1970, substantial exposure has been rare in Denmark. The present study aimed at investigating the extent to which these alterations have influenced the cancer risk of gardeners. METHODS: A historical cohort of 3156 male gardeners was followed from May 1975 until 2002 with regard to cancer incidence. RESULTS: The cancer incidence was significantly below the national average [standardized incidence ratio (SIR) 0.86, 95% confidence interval (95% CI) 0.79-0.94], but an analysis by birth cohort indicated marked differences with a downward tendency for younger birth cohorts. Among the gardeners born prior to 1915, significant increases were found for leukemia (12 cases, SIR 2.33, 95% CI 1.32-4.10) and soft tissue sarcoma (3 cases, SIR 5.87, 95% CI 1.89-18.20). CONCLUSIONS: Gardeners constitute a healthy worker group, but an increased risk of soft tissue sarcoma and leukemia is indicated for people born prior to 1915, a finding that may reflect substantial pesticide exposure during the late 1940s and the 1950s. Among the gardeners born in 1915 or later, no excess cancer risk was found. The latter finding suggests a cancer-preventive effect for safety recommendations and improved technical devices with respect to pesticide application, along with legislative control measures to reduce pesticide exposure.

[Treatment of stress, sick leave and occupational stability]. / Stressbehandling, sygefravaer og arbejdsfastholdelse.

INTRODUCTION: The aim was to describe a rehabilitation process of individuals with stress-related adjustment disorders and analysing the prognostic impact of certain individual factors with sick leave and work resumption as outcome. METHODS: A retrospective cohort from the period 1996-2004 was conducted by means of an audit of 220 files of patients who have visited an occupational health care unit. RESULTS: A still increasing number of patients, mainly working in public health and welfare institutions, were admitted during the nine year study period. The average rehabilitation duration was 144 days (range: 3-689). After that period a decrease in the number of individuals on sick leave was found, and a total of 62% had returned to work or remained in work. The only individual predictor having negative impact on ability to work was psychopharmacologic drug treatment (Odds Ratio: 0.43: 0.23-0.81), whereas somatic drug treatment, age, gender, skill, workplace, matrimony, and smoking all were without any significant influence on work ability. CONCLUSION: This study shows that an occupational rehabilitation process of patients with stress-related adjustment disorders seems to improve ability to resume work, but a minor group, especially those in psychopharmacologic drug treatment, need prolonged rehabilitation. More rigorous study design is needed to confirm these findings.

Occupational pesticide intoxications among farmers in Bolivia: a cross-sectional study.

BACKGROUND: Pesticide use and its consequences are of concern in Bolivia due to an intensive and increasing use. METHODS: To assess the magnitude and reasons for occupational pesticide intoxication, a cross-sectional study with interviews and blood-tests was performed among 201 volunteer farmers from 48 villages in the temperate and subtropical valleys in the eastern part of the Andes Mountains in Bolivia. Of these 171 male farmers using pesticides in their agricultural production were used in the statistical analysis, including linear- and logistic regression analysis. RESULTS: This study documented a frequent use of the most toxic pesticides among farmers who have had almost no instructions in how to use pesticides and protect themselves against the dangers of intoxication, reflected in the hazardous practices used when handling pesticides. Symptoms of intoxications were common in connection with spraying operations. The risk of experiencing symptoms and the serum cholinesterase activity were influenced by whether or not organophosphates were used and the number of times sprayed. The experience of symptoms was moreover influenced by the hygienic and personal protective measures taken during spraying operations while this had no influence on the serum cholinesterase level. CONCLUSION: The study showed that occupational pesticide intoxications were common among farmers and did depend on multiple factors. Pesticide use is probably one of the largest toxicological problems in Bolivia, and a coordinated action by authorities, society and international bodies is needed to limit the number of intoxications and the environmental pollution.