Morbidity Rates in an Area with High Livestock Density: A Registry-Based Study Including Different Groups of Patients with Respiratory Health Problems.

There is continuing debate and public health concern regarding the previously confirmed association between high livestock density and human health. The primary aim of the current study is to assess the prevalence of respiratory and other health problems in a livestock dense area in the Netherlands, based on recent longitudinal health data and a large sample. Analyses are expanded with the investigation of different subgroups of patients with respiratory health problems and the inclusion of various chronic and acute health outcomes, as well as prescribed medication. Prevalence of health symptoms and chronic conditions was assessed for the period 2014-2016, based on electronic health records registered in 26 general practices located in areas with intensive livestock farming in the Netherlands ("livestock dense area", n = 117,459 unique residents in total). These were compared with corresponding health data from general practices (n = 22) in different rural regions with a low density of livestock farms or other major environmental exposures ("control area", n = 85,796 unique residents in total). Multilevel regression models showed a significantly higher prevalence of pneumonia in the total sample in the livestock dense area, which was also observed among susceptible subgroups of children, the elderly, and patients with chronic obstructive pulmonary disease (COPD). Lower respiratory tract infections, respiratory symptoms, vertigo, and depression were also more common in the livestock dense area compared to the control area. In general, there were no significant differences in chronic conditions such as asthma, COPD, or lung cancer. Prescription rates for broad-spectrum antibiotics were more common among patients with pneumonia in the livestock dense area. Acute respiratory infections and symptoms, but not chronic conditions, were considerably more common in areas with a high livestock density. Identification of causal pathogens on the basis of serological analyses could further elucidate the underlying mechanisms behind the observed health effects.

Associations between pneumonia and residential distance to livestock farms over a five-year period in a large population-based study.

In a recent study of electronic health records (EHR) of general practitioners in a livestock-dense area in The Netherlands in 2009, associations were found between residential distance to poultry farms and the occurrence of community-acquired pneumonia (CAP). In addition, in a recent cross-sectional study in 2494 adults in 2014/2015 an association between CAP and proximity to goat farms was observed. Here, we extended the 2009 EHR analyses across a wider period of time (2009-2013), a wider set of health effects, and a wider set of farm types as potential risk sources. A spatial (transmission) kernel model was used to investigate associations between proximity to farms and CAP diagnosis for the period from 2009 to 2013, obtained from EHR of in total 140,059 GP patients. Also, associations between proximity to farms and upper respiratory infections, inflammatory bowel disease, and (as a control disease) lower back pain were analysed. Farm types included as potential risk sources in these analyses were cattle, (dairy) goats, mink, poultry, sheep, and swine. The previously found association between CAP occurrence and proximity to poultry farms was confirmed across the full 5-year study period. In addition, we found an association between increased risk for pneumonia and proximity to (dairy) goat farms, again consistently across all years from 2009 to 2013. No consistent associations were found for any of the other farm types (cattle, mink, sheep and swine), nor for the other health effects considered. On average, the proximity to poultry farms corresponds to approximately 119 extra patients with CAP each year per 100,000 people in the research area, which accounts for approximately 7.2% extra cases. The population attributable risk percentage of CAP cases in the research area attributable to proximity to goat farms is approximately 5.4% over the years 2009-2013. The most probable explanation for the association of CAP with proximity to poultry farms is thought to be that particulate matter and its components are making people more susceptible to respiratory infections. The causes of the association with proximity to goat farms is still unclear. Although the 2007-2010 Q-fever epidemic in the area probably contributed Q-fever related pneumonia cases to the observed additional cases in 2009 and 2010, it cannot explain the association found in later years 2011-2013.

Media experiences and associations with mental health among the bereaved of the MH17-disaster: A latent profile analysis.

Research has shown that the amount of media exposure is associated with post-event mental health problems. Whether bereaved individuals have negative experiences with media reports and whether they are associated with post-event mental health is unclear. This study evaluated these experiences and associations following the MH17-disaster. How media reports were experienced (nine topics, modified MAS), depression symptoms (QIDS-SR), functional problems (WSAS) and event-related coping-self-efficacy (CSE) were assessed about one year post-disaster (May-August 2015) among Dutch bereaved (N = 152). A substantial minority reported negative experiences such as reports made me angry (30%) and made me sad (48%). Latent profile analysis with symptoms, problems and coping self-efficacy as indicators, identified four classes of post-disaster mental health: a Well-functioning(class 1) , 35.1%; a Mild-problems(class 2) , 30.4%; a Sub-clinical(class 3) , 27.0%; and a Clinical(class 4) , 7.4%. Differences in symptoms, problems and coping self-efficacy levels between classes were large according to Cohen's ds. Multivariate logistic regression (MLR) showed that the Clinical(class 4) compared to the Well-functioning(class 1) , more often that felt that reports strongly "embarrassed me," "made me feel sad," "filled me with fear" and "served as a magnifying glass." Future research should assess opportunities and effects of limiting media consumption.

Remarkable spatial variation in the seroprevalence of Coxiella burnetii after a large Q fever epidemic.

BACKGROUND: Prior to the 2007-2010 Q fever epidemic in the Netherlands, the seroprevalence of antibodies against Coxiella burnetii in the general population was 1.5%, which is low compared to other countries. We aimed to determine the seroprevalence after the Q fever epidemic among people living in the affected area, compare the seroprevalence with the incidence of Q fever notifications during the 2007-2010 Q fever epidemic, and to identify farm exposures associated with having antibodies against C. burnetii. METHODS: During the period March 2014-February 2015, residents aged 18-70 years from two provinces were invited by general practitioners to complete a questionnaire on their symptoms and personal characteristics and to submit a blood sample. We used the mandatory provincial database of livestock licences to calculate distance to farms/farm animals for each participant. To compare ELISA-positive participants for C. burnetii antibodies with those who were negative, we calculated prevalence ratios (PR) using binominal regression. We compared the C. burnetii seroprevalence in the period March 2014-February 2015 with the incidence of Q fever notifications during the 2007-2010 Q fever epidemic at municipal level by calculating the Spearman correlation coefficient. RESULTS: Of the 2296 participants (response rate: 34%), 6.1% (n = 139, 95% CI 5.1-7.1%) had C. burnetii antibodies (range in municipalities: 1.7-14.1%). C. burnetii seroprevalence was higher in individuals living within 1000 m of goat farms (PR 3.0; 95% CI 1.4-6.4) or within 1000 m of > 50 goats (PR 1.9; 95% CI 1.2-3.0). Seroprevalence increased with decreasing distance to the closest goat farm that was infected during the epidemic years (< 500 m, PR 9.5, 95% CI 2.8-32; 500-1000 m, PR 4.5, 95% CI 2.6-7.7; 1000-1500 m, PR 2.2, 95% CI 1.1-4.3, 1500-2000 m, PR 1.2, 95% CI 0.6-2.5; > 2000 reference group). There was no significant correlation between C. burnetii seroprevalence and Q fever incidence during the 2007-2010 epidemic (r s = 0.42, p = 0.156). CONCLUSIONS: Results showed a remarkable spatial variation in C. burnetii seroprevalence in a relatively small livestock dense area. It confirms previous evidence that the Q fever epidemic was primarily the result of airborne C. burnetii transmission from Q fever affected goat farms.

Increased risk of pneumonia in residents living near poultry farms: does the upper respiratory tract microbiota play a role?

BACKGROUND: Air pollution has been shown to increase the susceptibility to community-acquired pneumonia (CAP). Previously, we observed an increased incidence of CAP in adults living within 1 km from poultry farms, potentially related to particulate matter and endotoxin emissions. We aim to confirm the increased risk of CAP near poultry farms by refined spatial analyses, and we hypothesize that the oropharyngeal microbiota composition in CAP patients may be associated with residential proximity to poultry farms. METHODS: A spatial kernel model was used to analyze the association between proximity to poultry farms and CAP diagnosis, obtained from electronic medical records of 92,548 GP patients. The oropharyngeal microbiota composition was determined in 126 hospitalized CAP patients using 16S-rRNA-based sequencing, and analyzed in relation to residential proximity to poultry farms. RESULTS: Kernel analysis confirmed a significantly increased risk of CAP when living near poultry farms, suggesting an excess risk up to 1.15 km, followed by a sharp decline. Overall, the oropharyngeal microbiota composition differed borderline significantly between patients living <1 km and ≥1 km from poultry farms (PERMANOVA p = 0.075). Results suggested a higher abundance of Streptococcus pneumoniae (mean relative abundance 34.9% vs. 22.5%, p = 0.058) in patients living near poultry farms, which was verified by unsupervised clustering analysis, showing overrepresentation of a S. pneumoniae cluster near poultry farms (p = 0.049). CONCLUSION: Living near poultry farms is associated with an 11% increased risk of CAP, possibly resulting from changes in the upper respiratory tract microbiota composition in susceptible individuals. The abundance of S. pneumoniae near farms needs to be replicated in larger, independent studies.

Livestock-associated risk factors for pneumonia in an area of intensive animal farming in the Netherlands.

Previous research conducted in 2009 found a significant positive association between pneumonia in humans and living close to goat and poultry farms. However, as this result might have been affected by a large goat-related Q fever epidemic, the aim of the current study was to re-evaluate this association, now that the Q-fever epidemic had ended. In 2014/15, 2,494 adults (aged 20-72 years) living in a livestock-dense area in the Netherlands participated in a medical examination and completed a questionnaire on respiratory health, lifestyle and other items. We retrieved additional information for 2,426/2,494 (97%) participants from electronic medical records (EMR) from general practitioners. The outcome was self-reported, physician-diagnosed pneumonia or pneumonia recorded in the EMR in the previous three years. Livestock license data was used to determine exposure to livestock. We quantified associations between livestock exposures and pneumonia using odds ratios adjusted for participant characteristics and comorbidities (aOR). The three-year cumulative frequency of pneumonia was 186/2,426 (7.7%). Residents within 2,000m of a farm with at least 50 goats had an increased risk of pneumonia, which increased the closer they lived to the farm (2,000m aOR 1.9, 95% CI 1.4-2.6; 500m aOR 4.4, 95% CI 2.0-9.8). We found no significant associations between exposure to other farm animals and pneumonia. However, when conducting sensitivity analyses using pneumonia outcome based on EMR only, we found a weak but statistically significant association with presence of a poultry farm within 1,000m (aOR: 1.7, 95% CI 1.1-2.7). Living close to goat and poultry farms still constitute risk factors for pneumonia. Individuals with pneumonia were not more often seropositive for Coxiella burnetii, indicating that results are not explained by Q fever. We strongly recommend identification of pneumonia causes by the use of molecular diagnostics and investigating the role of non-infectious agents such as particulate matter or endotoxins.

An International Comparison of the Instigation and Design of Health Registers in the Epidemiological Response to Major Environmental Health Incidents.

CONTEXT: Epidemiological preparedness is vital in providing relevant, transparent, and timely intelligence for the management, mitigation, and prevention of public health impacts following major environmental health incidents. A register is a set of records containing systematically collected, standardized data about individual people. Planning for a register of people affected by or exposed to an incident is one of the evolving tools in the public health preparedness and response arsenal. OBJECTIVE: We compared and contrasted the instigation and design of health registers in the epidemiological response to major environmental health incidents in England, France, Italy, the Netherlands, and the United States. DESIGN: Consultation with experts from the 5 nations, supplemented with a review of gray and peer-reviewed scientific literature to identify examples where registers have been used. SETTING: Populations affected by or at risk from major environmental health incidents in England, France, Italy, the Netherlands, and the United States. METHODS: Nations were compared with respect to the (1) types of major incidents in their remit for considering a register; (2) arrangements for triggering a register; (3) approaches to design of register; (4) arrangements for register implementation; (5) uses of registers; and (6) examples of follow-up studies. RESULTS: Health registers have played a key role in the effective public health response to major environmental incidents, including sudden chemical, biological, radiological, or nuclear, as well as natural, more prolonged incidents. Value has been demonstrated in the early and rapid deployment of health registers, enabling the capture of a representative population. CONCLUSION: The decision to establish a health register must ideally be confirmed immediately or soon after the incident using a set of agreed criteria. The establishment of protocols for the instigation, design, and implementation of health registers is recommended as part of preparedness activities. Key stakeholders must be aware of the importance of, and protocols for, establishing a register.Agencies will find value in preparing and implementing registers as part of an effective public health response to major environmental incidents, including sudden chemical, biological, radiological, or nuclear incidents, as well as natural, more prolonged incidents.

Noise sensitivity: Symptoms, health status, illness behavior and co-occurring environmental sensitivities.

Epidemiological evidence on the symptomatic profile, health status and illness behavior of people with subjective sensitivity to noise is still scarce. Also, it is unknown to what extent noise sensitivity co-occurs with other environmental sensitivities such as multi-chemical sensitivity and sensitivity to electromagnetic fields (EMF). A cross-sectional study performed in the Netherlands, combining self-administered questionnaires and electronic medical records of non-specific symptoms (NSS) registered by general practitioners (GP) allowed us to explore this further. The study sample consisted of 5806 participants, drawn from 21 general practices. Among participants, 722 (12.5%) responded "absolutely agree" to the statement "I am sensitive to noise", comprising the high noise-sensitive (HNS) group. Compared to the rest of the sample, people in the HNS group reported significantly higher scores on number and duration of self-reported NSS, increased psychological distress, decreased sleep quality and general health, more negative symptom perceptions and higher prevalence of healthcare contacts, GP-registered NSS and prescriptions for antidepressants and benzodiazepines. These results remained robust after adjustment for demographic, residential and lifestyle characteristics, objectively measured nocturnal noise exposure from road-traffic and GP-registered morbidity. Co-occurrence rates with other environmental sensitivities varied between 9% and 50%. Individuals with self-declared sensitivity to noise are characterized by high prevalence of multiple NSS, poorer health status and increased illness behavior independently of noise exposure levels. Findings support the notion that different types of environmental sensitivities partly overlap.

Clinically defined non-specific symptoms in the vicinity of mobile phone base stations: A retrospective before-after study.

The number of mobile phone base station(s) (MPBS) has been increasing to meet the rapid technological changes and growing needs for mobile communication. The primary objective of the present study was to test possible changes in prevalence and number of NSS in relation to MPBS exposure before and after increase of installed MPBS antennas. A retrospective cohort study was conducted, comparing two time periods with high contrast in terms of number of installed MPBS. Symptom data were based on electronic health records from 1069 adult participants, registered in 9 general practices in different regions in the Netherlands. All participants were living within 500m from the nearest bases station. Among them, 55 participants reported to be sensitive to MPBS at T1. A propagation model combined with a questionnaire was used to assess indoor exposure to RF-EMF from MPBS at T1. Estimation of exposure at T0 was based on number of antennas at T0 relative to T1. At T1, there was a >30% increase in the total number of MPBS antennas. A higher prevalence for most NSS was observed in the MPBS-sensitive group at T1 compared to baseline. Exposure estimates were not associated with GP-registered NSS in the total sample. Some significant interactions were observed between MPBS-sensitivity and exposure estimates on risk of symptoms. Using clinically defined outcomes and a time difference of >6years it was demonstrated that RF-EMF exposure to MPBS was not associated with the development of NSS. Nonetheless, there was some indication for a higher risk of NSS for the MPBS-sensitive group, mainly in relation to exposure to UMTS, but this should be interpreted with caution. Results have to be verified by future longitudinal studies with a particular focus on potentially susceptible population subgroups of large sample size and integrated exposure assessment.

Health effects from low-frequency noise and infrasound in the general population: Is it time to listen? A systematic review of observational studies.

A systematic review of observational studies was conducted to assess the association between everyday life low-frequency noise (LFN) components, including infrasound and health effects in the general population. Literature databases Pubmed, Embase and PsycInfo and additional bibliographic sources such as reference sections of key publications and journal databases were searched for peer-reviewed studies published from 2000 to 2015. Seven studies met the inclusion criteria. Most of them examined subjective annoyance as primary outcome. The adequacy of provided information in the included papers and methodological quality of studies was also addressed. Moreover, studies were screened for meta-analysis eligibility. Some associations were observed between exposure to LFN and annoyance, sleep-related problems, concentration difficulties and headache in the adult population living in the vicinity of a range of LFN sources. However, evidence, especially in relation to chronic medical conditions, was very limited. The estimated pooled prevalence of high subjective annoyance attributed to LFN was about 10%. Epidemiological research on LFN and health effects is scarce and suffers from methodological shortcomings. Low frequency noise in the everyday environment constitutes an issue that requires more research attention, particularly for people living in the vicinity of relevant sources.

Assessing non-specific symptoms in epidemiological studies: Development and validation of the Symptoms and Perceptions (SaP) questionnaire.

OBJECTIVES: To describe the development of the Symptoms and Perceptions (SaP) questionnaire, a new instrument measuring diversity and severity features and related perceptions of non-specific (physical and psychological) symptoms (NSS) and to test its reliability and validity within an epidemiological setting. METHODS: First, a Delphi study was performed to develop the items of the questionnaire. Its psychometric properties were then tested within the context of an epidemiological study. This study yielded questionnaire data and general practice registry data from a sample of 5933 Dutch adults. Principal component analyses (PCA) were performed to test the factorial structure of the symptom assessment subscales of the SaP. Indicators of reliability and convergent validity were examined separately for the questionnaire parts of symptoms and perceptions. Criterion validity of the symptom scores of the SaP was also explored. RESULTS: The factorial structure of the symptom subscales reflected meaningful sets of clusters, indicative of the representation of all relevant organ systems. The SaP showed high reliability and good convergent validity for both the symptoms and perceptions part. It was also able to identify, to a certain degree, cases of diagnosed somatoform disorders and multiple NSS in primary care. Additionally, the scores on the "psychological" factor fairly predicted the diagnosis of common mental disorders. CONCLUSIONS: The SaP questionnaire is a reliable and valid self-reported measure of diverse features of NSS and corresponding perceptions. It can also be a useful tool for the identification of multiple somatic symptoms and related disorders in general practice and assessment of psychological problems in epidemiological studies. Further validation of the questionnaire in different samples and settings will establish the promising psychometric properties demonstrated in the present study.

The relationship of modern health worries to non-specific physical symptoms and perceived environmental sensitivity: A study combining self-reported and general practice data.

OBJECTIVE: The present study investigates the association of modern health worries (MHW) with self-reported as well as general practitioner (GP)-registered non-specific physical symptoms (NSPS), medication use, alternative therapy consultations, sleep quality and quality of life. The interrelation between MHW, general environmental sensitivity and the aforementioned outcomes is also explored. METHODS: Self-reported questionnaires and data from electronic medical records from 21 general practices in The Netherlands were combined in a sample of 5933 adult participants. RESULTS: The majority of the participants reported increased worries about potential health effects from environmental exposures. The highest worry scores were reported by people who perceived themselves as more vulnerable to environmental stressors. After adjustment for socio-demographic characteristics and diagnosed psychiatric morbidity, higher MHW were significantly associated with increased self-reported prevalence and duration of NSPS, symptom-related healthcare utilization, GP-registered NSPS, alternative therapy consultations and lower sleep quality and quality of life. These associations were statistically mediated by perceived environmental sensitivity. No association was observed between worries and GP-registered medication prescriptions. CONCLUSION: Modern health worries are very common in the general population. They are associated with self-reported as well as clinically defined NSPS and as such might play a key role in the process of developing and maintaining environmental sensitivities and related symptoms. A large cross-cultural longitudinal study would help to determine important aspects such as temporal precedence and stability of MHW and the relevant psychosocial context within which symptomatic conditions occur.

Actual and perceived exposure to electromagnetic fields and non-specific physical symptoms: an epidemiological study based on self-reported data and electronic medical records.

BACKGROUND: There is continuing scientific debate and increasing public concern regarding the possible effects of electromagnetic fields (EMF) on general population's health. To date, no epidemiological study has investigated the possible association between actual and perceived EMF exposure and non-specific physical symptoms (NSPS) and sleep quality, using both self-reported and general practice (GP)-registered data. METHODS: A health survey of adult (≥ 18) participants (n=5933) in the Netherlands was combined with the electronic medical records (EMRs) of NSPS as registered by general practitioners. Characterization of actual exposure was based on several proxies, such as prediction models of radiofrequency (RF)-EMF exposure, geo-coded distance to high-voltage overhead power lines and self-reported use/distance of/to indoor electrical appliances. Perceived exposure and the role of psychological variables were also examined. RESULTS: Perceived exposure had a poor correlation with the actual exposure estimates. No significant association was found between modeled RF-EMF exposure and the investigated outcomes. Associations with NSPS were observed for use of an electric blanket and close distance to an electric charger during sleep. Perceived exposure, perceived control and avoidance behavior were associated with the examined outcomes. The association between perceived exposure was stronger for self-reported than for GP-registered NSPS. There was some indication, but no consistent pattern for an interaction between idiopathic environmental intolerance (IEI-EMF) and the association between actual exposure and NSPS. CONCLUSIONS: In conclusion, there is no convincing evidence for an association between everyday life RF-EMF exposure and NSPS and sleep quality in the population. Better exposure characterization, in particular with respect to sources of extremely low frequency magnetic fields (ELF-MF) is needed to draw more solid conclusions. We argue that perceived exposure is an independent determinant of NSPS.

Comparing non-specific physical symptoms in environmentally sensitive patients: prevalence, duration, functional status and illness behavior.

OBJECTIVE: Little is known about the potential clinical relevance of non-specific physical symptoms (NSPS) reported by patients with self-reported environmental sensitivities. This study aimed to assess NSPS in people with general environmental sensitivity (GES) and idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) and to determine differences in functional status and illness behavior. METHODS: An epidemiological study was conducted in the Netherlands, combining self-administered questionnaires with the electronic medical records of the respondents as registered by general practitioners. Analyses included n=5789 registered adult (≥18 years) patients, comprising 5073 non-sensitive (NS) individuals, 514 in the GES group and 202 in the IEI-EMF group. RESULTS: Participants with GES were about twice as likely to consult alternative therapy compared to non-sensitive individuals; those with IEI-EMF were more than three times as likely. Moreover, there was a higher prevalence of symptoms and medication prescriptions and longer symptom duration among people with sensitivities. Increasing number and duration of self-reported NSPS were associated with functional impairment, illness behavior, negative symptom perceptions and prevalence of GP-registered NSPS in the examined groups. CONCLUSION: Even after adjustment for medical and psychiatric morbidity, environmentally sensitive individuals experience poorer health, increased illness behavior and more severe NSPS. The number and duration of self-reported NSPS are important components of symptom severity and are associated with characteristics similar to those of NSPS in primary care. The substantial overlap between the sensitive groups strengthens the notion that different types of sensitivities might be part of one, broader environmental illness.

Police officers: a high-risk group for the development of mental health disturbances? A cohort study.

OBJECTIVES: Policing is generally considered a high-risk profession for the development of mental health problems, but this assumption lacks empirical evidence. Research question of the present study is to what extent mental health disturbances, such as (very) severe symptoms of anxiety, depression and hostility are more prevalent among police officers than among other occupational groups. DESIGN: Multicomparative cross-sectional study using the data of several cross-sectional and longitudinal studies in the Netherlands. PARTICIPANTS: Two samples of police officers (N=144 and 503), employees of banks (N=1113) and employees of banks who were robbed (N=144); employees of supermarkets (N=335), and a psychiatric hospital (N=219), employees of a governmental social welfare organisation (N=76), employees who followed a training based on rational-motive therapy to strengthen their assertiveness (N=710), soldiers before deployment (N=278) and before redeployment (N=236) and firefighters (N=123). The numbers refer to respondents with complete data. PRIMARY OUTCOMES: Prevalence of severe (subclinical level) and very severe symptoms (clinical level) were computed using the Dutch norm tables (80th percentile and 95th percentile, respectively) of the Symptom Check List Revised (SCL-90-R). All comparisons were controlled for age, gender and education. RESULTS: Multivariate logistic regression and analyses showed that the prevalence of clinical and subclinical levels of symptoms of anxiety, depression and hostility among police officers were not significantly higher than among comparison groups. The same pattern was found for the other SCL-90-R subscales. CONCLUSIONS: We found no indications that self-reported mental health disturbances were more prevalent among police officers than among groups of employees that are not considered high-risk groups, such as employees of banks, supermarkets, psychiatric hospital and soldiers before deployment.

Q fever and pneumonia in an area with a high livestock density: a large population-based study.

Concerns about public health risks of intensive animal production in The Netherlands continue to rise, in particular related to outbreaks of infectious diseases. The aim was to investigate associations between the presence of farm animals around the home address and Q fever and pneumonia.Electronic medical record data for the year 2009 of all patients of 27 general practitioners (GPs) in a region with a high density of animal farms were used. Density of farm animals around the home address was calculated using a Geographic Information System. During the study period, a large Q fever outbreak occurred in this region. Associations between farm exposure variables and pneumonia or 'other infectious disease', the diagnosis code used by GPs for registration of Q fever, were analyzed in 22,406 children (0-17 y) and 70,142 adults (18-70 y), and adjusted for age and sex. In adults, clear exposure-response relationships between the number of goats within 5 km of the home address and pneumonia and 'other infectious disease' were observed. The association with 'other infectious disease' was particularly strong, with an OR [95%CI] of 12.03 [8.79-16.46] for the fourth quartile (>17,190 goats) compared with the first quartile (<2,251 goats). The presence of poultry within 1 km was associated with an increased incidence of pneumonia among adults (OR [95%CI] 1.25 [1.06-1.47]).A high density of goats in a densely populated region was associated with human Q fever. The use of GP records combined with individual exposure estimates using a Geographic Information System is a powerful approach to assess environmental health risks.

Non-specific physical symptoms and electromagnetic field exposure in the general population: can we get more specific? A systematic review.

OBJECTIVE: A systematic review of observational studies was performed to address the strength of evidence for an association between actual and perceived exposure to electromagnetic fields (EMF) and non-specific physical symptoms (NSPS) in the general population. To gain more insight into the magnitude of a possible association, meta-analyses were conducted. METHODS: Literature databases Medline, Embase, SciSearch, PsychInfo, Psyndex and Biosis and additional bibliographic sources such as reference sections of key publications were searched for the detection of studies published between January 2000 and April 2011. RESULTS: Twenty-two studies met our inclusion criteria. Qualitative assessment of the epidemiological evidence showed either no association between symptoms and higher EMF exposure or contradictory results. To strengthen our conclusions, random effects meta-analyses were performed, which produced the following results for the association with actual EMF; for symptom severity: Headache odds ratio (OR)=1.65; 95% confidence interval (CI)=0.88-3.08, concentration problems OR=1.28; 95% CI=0.56-2.94, fatigue-related problems OR=1.15; 95% CI=0.59-2.27, dizziness-related problems OR=1.38; 95% CI=0.92-2.07. For symptom frequency: headache OR=1.01; 95% CI=0.66-1.53, fatigue OR=1.12; 95% CI=0.60-2.07 and sleep problems OR=1.18; 95% CI=0.80-1.74. Associations between perceived exposure and NSPS were more consistently observed but a meta-analysis was not performed due to considerable heterogeneity between the studies. CONCLUSIONS: This systematic review and meta-analysis finds no evidence for a direct association between frequency and severity of NSPS and higher levels of EMF exposure. An association with perceived exposure seems to exist, but evidence is still limited because of differences in conceptualization and assessment methods.

Non-specific physical symptoms in relation to actual and perceived proximity to mobile phone base stations and powerlines.

BACKGROUND: Evidence about a possible causal relationship between non-specific physical symptoms (NSPS) and exposure to electromagnetic fields (EMF) emitted by sources such as mobile phone base stations (BS) and powerlines is insufficient. So far little epidemiological research has been published on the contribution of psychological components to the occurrence of EMF-related NSPS. The prior objective of the current study is to explore the relative importance of actual and perceived proximity to base stations and psychological components as determinants of NSPS, adjusting for demographic, residency and area characteristics. METHODS: Analysis was performed on data obtained in a cross-sectional study on environment and health in 2006 in the Netherlands. In the current study, 3611 adult respondents (response rate: 37%) in twenty-two Dutch residential areas completed a questionnaire. Self-reported instruments included a symptom checklist and assessment of environmental and psychological characteristics. The computation of the distance between household addresses and location of base stations and powerlines was based on geo-coding. Multilevel regression models were used to test the hypotheses regarding the determinants related to the occurrence of NSPS. RESULTS: After adjustment for demographic and residential characteristics, analyses yielded a number of statistically significant associations: Increased report of NSPS was predominantly predicted by higher levels of self-reported environmental sensitivity; perceived proximity to base stations and powerlines, lower perceived control and increased avoidance (coping) behavior were also associated with NSPS. A trend towards a moderator effect of perceived environmental sensitivity on the relation between perceived proximity to BS and NSPS was verified (p = 0.055). There was no significant association between symptom occurrence and actual distance to BS or powerlines. CONCLUSIONS: Perceived proximity to BS, psychological components and socio-demographic characteristics are associated with the report of symptomatology. Actual distance to the EMF source did not show up as determinant of NSPS.

Impact of a technological disaster on young children: a five-year postdisaster multiinformant study.

Children exposed to a technological disaster during an understudied part of the lifespan, preschool age and early middle childhood, were assessed in a 5-year follow-up regarding mental health problems, anxiety disorder symptoms, depressive symptoms, physical symptoms, and posttraumatic stress symptoms. Exposed children and their parents (n = 264) reported significantly more problems than controls (n = 515). The differences were greater for conduct problems (including hyperactivity) and physical symptoms, than for anxiety and depression. The long-term effects of a technological disaster on children of pre-school age at exposure appear to differ from those in children, who were victimized at a later age. This may reflect interference with completion of specific developmental tasks.