Urinary pesticide mixture patterns and exposure determinants in the adult population from the Netherlands and Switzerland: Application of a suspect screening approach.

INTRODUCTION: Non-occupational sources of pesticide exposure may include domestic pesticide usage, diet, occupational exposure of household members, and agricultural activities in the residential area. We conducted a study with the ambition to characterize pesticide mixture patterns in a sample of the adult population of the Netherlands and Switzerland, using a suspect screening approach and to identify related exposure determinants. METHODS: A total of 105 and 295 adults participated in the Dutch and Swiss studies, respectively. First morning void urine samples were collected and analyzed in the same laboratory. Harmonized questionnaires about personal characteristics, pesticide-related activities, and diet were administered. Detection rates and co-occurrence patterns were calculated to explore internal pesticide exposure patterns. Censored linear and logistic regression models were constructed to investigate the association between exposure and domestic pesticide usage, consumption of homegrown and organic foods, household members' exposure, and distance to agricultural and forest areas. RESULTS: From the 37 detected biomarkers, 3 (acetamiprid (-CH2), chlorpropham (4-HSA), and flonicamid (-C2HN)) were detected in ≥40% of samples. The most frequent combination of biomarkers (acetamiprid-flonicamid) was detected in 22 (5.5%) samples. Regression models revealed an inverse association between high organic vegetable and fruit consumption and exposure to acetamiprid, chlorpropham, propamocarb (+O), and pyrimethanil (+O + SO3). Within-individual correlations in repeated samples (summer/winter) from the Netherlands were low (≤0.3), and no seasonal differences in average exposures were observed in Switzerland. CONCLUSION: High consumption of organic fruit and vegetables was associated with lower pesticide exposure. In the two countries, detection rates and co-occurrence were typically low, and within-person variability was high. Our study results provide an indication for target biomarkers to include in future studies aimed at quantifying urinary exposure levels in European adult populations.

Argumentation Analysis of Risk Assessments: The Case of Perfluorooctanoic Acid.

Risk assessment of chemicals can be based on toxicology and/or epidemiology. The choice of toxicological or epidemiological data can result in different health-based guidance values (HBGVs). Communicating the underlying argumentation is important to explain these differences to the public and policymakers. In this article, we explore the argumentation used to justify the use of toxicological or epidemiological data in the derivation of HBGVs in four different risk assessments for the chemical Perfluorooctanoic acid (PFOA). The pragma-dialectical argumentation theory (PDAT) is hereby applied. The argumentations to select relevant health endpoints or certain studies to infer causality appeared mainly based on "symptomatic relations," that is, study results are used as characteristic of what was claimed to be a causal relation without delving into the actual causal argumentation that preceded it. Starting points that are at the basis of the chain of arguments remained implicit. Argumentation to use epidemiological and/or toxicological data was only briefly mentioned and the underlying argumentative foundation that led to the conclusion was seldom found or not addressed at all. The decision to include/exclude information was made based on the availability of data, or the motives for the choice remained largely unclear. We conclude that more depth in argumentation and a subordinative chain of arguments is needed to better disclose the underlying reasoning leading to a certain health-based guidance value (HBGV). More explicit identification and discussion of starting points could be a valuable addition to general risk assessment frameworks for maximum use of toxicological and epidemiological data and shared conclusions of the assessment.

Challenges of exposure assessment for health studies in the aftermath of chemical incidents and disasters.

Exposure assessment during and after acute chemical incidents and disasters is essential for health studies that may follow. During chemical incidents, the focus usually lies on risk assessment and afterward attention shifts toward possible (long-term) health effects. This may lead to insufficient available data on exposure to study the association between exposure and health outcome, and collection of additional exposure data is often required. Literature on health studies conducted after several chemical incidents was reviewed to obtain better insight on the needs of health studies. Four different types of scenarios were distinguished based on when exposure data were collected and the exposure data used for health studies. These four scenarios gave insight on exposure data needed for conclusive health studies and when different methods of exposure data collection should be used. Literature indicated that adequate and rapid exposure assessment during chemical incidents is vital for health studies, because data that are not collected during or directly after an incident may be irretrievably lost. Poor exposure assessment is not always the only problem in health studies. Problems in health studies including poor exposure assessment may be prevented when the general design and needs of health studies are taken into account when designing contingency plans. Together with measures that will help facilitate funding, design, and coordination of health studies, disaster management programs should, among others, prepare for methods that lead to a swift identification of released substances, determination of concentrations and dispersion of released substances, designing basic questionnaire outlines, and rapid evaluation of the usefulness and necessity of employing biological sampling.

Risk factors for physical symptoms after a disaster: a longitudinal study.

BACKGROUND: Although symptoms such as fatigue, headache and pain in bones and muscles are common after disasters, risk factors for these symptoms among disaster survivors have rarely been studied. We examined predisposing, precipitating and perpetuating factors for these physical symptoms among survivors of a man-made disaster. In addition, we examined whether risk factors for physical symptoms differ between survivors and controls. METHOD: Survivors completed a questionnaire 3 weeks (n=1567), 18 months and 4 years after the disaster. Symptoms and risk factors were measured using validated questionnaires. A comparison group was included at waves 2 and 3 (n=821). Random coefficient analysis (RCA) was used to study risk factors for symptoms. RESULTS: Female gender [beta (beta)=1.0, 95% confidence interval (CI) 0.6-1.4], immigrant status (beta=1.0, 95% CI 0.6-1.4) and pre-disaster psychological problems (beta=0.8, 95% CI 0.1-1.4) were predisposing factors for symptoms. Although disaster-related factors were predictors, the relationship between symptoms and disaster-related factors was not very strong and the magnitude of this association was reduced when perpetuating factors were added. Intrusions and avoidance, depression, anxiety and sleeping problems were important perpetuating factors for physical symptoms among survivors and mediated the association between traumatic stress and physical symptoms. Risk factors for symptoms were comparable between survivors and controls. CONCLUSIONS: The results indicate that health-care workers should be alert for physical symptoms among female survivors, immigrant survivors and individuals with a high level of psychological problems both before and after a disaster.

A longitudinal comparative study of the physical and mental health problems of affected residents of the firework disaster Enschede, The Netherlands.

OBJECTIVES: After the firework disaster in Enschede, The Netherlands, on 13 May 2000, a longitudinal health study was carried out. Study questions were: (1) did the health status change over this period; and (2) how is the health status 18 months after the disaster compared with controls? STUDY DESIGN: A longitudinal comparative study with two surveys at 3 weeks and 18 months after the disaster. METHODS: A control group for the affected residents was included in the second survey. Respondents filled in a set of validated questionnaires measuring their physical and mental health problems. RESULTS: The prevalence of physical and emotional role limitations, severe sleeping problems, feelings of depression and anxiety, as well as intrusion and avoidance decreased from 3 weeks to 18 months after the disaster for the affected residents. Independent of background characteristics and other life events, residents had 1.5 to three times more health problems than the control group; for example, physical role limitations (odds ratio [OR]=1.5, 95% confidence interval [CI] 1.2-2.0) and anxiety (OR=3.1, 95% CI 2.4-4.2). CONCLUSIONS: Although health problems decreased compared with 3 weeks after the disaster, 18 months after the disaster, the affected residents had more health problems than the people from the control group.

Aircraft noise around a large international airport and its impact on general health and medication use.

AIMS: To assess the prevalence of general health status, use of sleep medication, and use of medication for cardiovascular diseases, and to study their relation to aircraft noise exposure. METHODS: These health indicators were measured by a cross-sectional survey among 11 812 respondents living within a radius of 25 km around Schiphol airport (Amsterdam). RESULTS: Adjusted odds ratios ranged from 1.02 to 2.34 per 10 dB(A) increase in L(den). The associations were statistically significant for all indicators, except for use of prescribed sleep medication or sedatives and frequent use of this medication. None of the health indicators were associated with aircraft noise exposure during the night, but use of non-prescribed sleep medication or sedatives was associated with aircraft noise exposure during the late evening (OR = 1.72). Vitality related health complaints such as tiredness and headache were associated with aircraft noise, whereas most other physical complaints were not. Odds ratios for the vitality related complaints ranged from 1.16 to 1.47 per 10 dB(A) increase in L(den). A small fraction of the prevalence of poor self rated health (0.13), medication for cardiovascular diseases or increased blood pressure (0.08), and sleep medication or sedatives (0.22) could be attributed to aircraft noise. Although the attributable fraction was highest in the governmentally noise regulated area, aircraft noise had more impact in the non-regulated area, due to the larger population. CONCLUSIONS: Results suggest associations between community exposure to aircraft noise and the health indicators poor general health status, use of sleep medication, and use of medication for cardiovascular diseases.

Perceptual differences regarding health and environmental problems and their remedies in two states of the former Czechoslovakia.

In the framework of the Central European Study on Air pollution and Respiratory Health (CESAR), a risk perception and risk communication study was carried out in a total of 25 areas in Bulgaria, the Czech Republic, Hungary, Poland, Romania and the Slovak Republic. This paper is focused on the differences of perception between the Czech (CR) and the Slovak Republic (SR), and the other involved countries. The analysis is based on the data of a structured risk perception questionnaire survey of a random population sample. 6,043 completed questionnaires were collected from the total number of 14,400 distributed ones in 25 areas of the 6 countries. The risk perception was different in the CR and the SR, mainly concerning local environment and health of children in the CR and drug abuse including alcohol consumption and AIDS in the SR. In both countries environmental and health problems were seen as important, but the perceived responsibility for finding a solution was placed with different kinds of institutions.

Immune biomarkers in relation to exposure to particulate matter: a cross-sectional survey in 17 cities of Central Europe.

Human population data on air pollution and its effects on the immune system are scarce. A survey was conducted within the framework of the Central European Study of Air Quality and Respiratory Health (CESAR) to measure a panel of immune biomarkers in children of Bulgaria, Czech Republic, Hungary, Poland, Romania, and Slovakia. Seventeen cities were chosen to represent a wide range of exposure to outdoor air pollution. In each, ambient particulate matter of less than 10 microns diameter and less than 2.5 microns diameter (PM10 and PM2.5) were measured with a Harvard impactor. Blood was collected from 366 school children aged 9 to 11 yr between 11 April and 10 May 1996. The percentage of B, total T, CD4+, CD8+, and natural killer (NK) lymphocytes was determined by flow cytometry (Becton Dickinson); total immunoglobulins of class G, M, A and E (IgG, IgM, IgA, and IgE) were measured in serum using nephelometry (Behring). Associations between PM and each log-transformed biomarker concentration were studied by linear regression, in a two-stage model. The yearly average concentrations varied from 41 to 96 micrograms/m3 for PM10 across the 17 study areas, from 29 to 67 micrograms/m3 for PM2.5, and from 12 to 38 micrograms/m3 for PM10-2.5 (coarse). Number of B, CD4+, CD8+, and NK lymphocytes increased with increasing concentration of PM, having adjusted for age, gender, parental smoking, laboratory of analysis, and recent respiratory illness. Differences in lymphocyte number were larger and statistically significant for exposure to PM2.5. Similar results were found when we examined the association between PM and lymphocyte number separately for each laboratory. Total IgG was increased with increasing concentration of PM, significantly in the case of PM2.5. When we repeated the analyses with two other statistical approaches the results did not differ from those reported here. The effect of coarse PM on lymphocyte numbers appears small in comparison to PM2.5. One possible interpretation of our findings is that long-term exposure to airborne particulates leads to inflammation of the airways and activation of the cellular and humoral immune system.

An aggregate public health indicator to represent the impact of multiple environmental exposures.

We present a framework to aggregate divergent health impacts associated with different types of environmental exposures, such as air pollution, residential noise, and large technologic risks. From the policy maker's point of view, there are at least three good reasons for this type of aggregation: comparative risk evaluation (for example, setting priorities), evaluation of the efficiency of environmental policies in terms of health gain, and characterizing health risk associated with geographical accumulation of multiple environmental exposures. The proposed impact measure integrates three important dimensions of public health: life expectancy, quality of life, and number of people affected. Time is the unit of measurement. "Healthy life years" are either lost by premature death or by loss of quality of life, measured as discounted life years within a population. Severity weights (0 for perfect health, 1 for death) are assigned to discount the time spent with conditions associated with environmental exposures. We combined information on population exposure distribution, exposure response relations, incidence, and prevalence rates to estimate annual numbers of people affected and the duration of the condition, including premature death. Using data from the fourth Dutch National Environmental Outlook, we estimated that the long-term effects of particulate air pollution account for almost 60% of the total environment-related health loss in the Netherlands as modeled here. Environmental noise accounts for 24%, indoor air pollution (environmental tobacco smoke, radon, and dampness, as well as lead in drinking water) for around 6%, and food poisoning (or infection) for more than 3%. The contribution of this set of environmental exposures to the total annual burden of disease in the Netherlands is less than 5%.

Mechanical modifications to human pericardium after a brief immersion in 0.625% glutaraldehyde.

BACKGROUND AND AIMS OF THE STUDY: The use of human pericardium pretreated for 10 min with 0.625% glutaraldehyde (GLUT) in valvular repair or intracardiac reconstruction has produced good results. However, to date, no investigations have been made to determine the mechanical changes that occur in the tissue following such pretreatment. METHODS: Human pericardial samples were harvested from 25 patients and immersed in GLUT for increasing times (5, 10, 30, 60 min and 6 months). Either untreated human pericardium or bovine pericardium treated for six months with GLUT served as controls. Tensile tests were performed with a uniaxial load machine and a pulsative bench. Fatigue testing was for 14 days; each sample was tested at 1,200 cycles/min at a controlled pressure of 90-120 mmHg. RESULTS: Untreated tissue thickness was 0.44+/-0.16 mm, but after six months GLUT treatment it was 0.53+/-0.15 mm (p<0.001). There was a 13.7% shrinkage of tissue after six months immersion. Strain was significantly greater in treated tissue than in untreated tissue, while stiffness decreased with the duration of GLUT immersion. Young's modulus was significantly lower after six months GLUT treatment (0.26+/-0.06 MPa) compared with untreated, and 5-, 10- and 30-min GLUT treatment (0.32+/-0.15, 0.35+/-0.09, 0.32+/-0.09 and 0.36+/-0.10 MPa (p<0.05)), respectively. Creep was greater after six months GLUT treatment (0.5+/-0.03%) than in untreated and 10-, 30- and 60-min treatments (0.3+/-0.50, 0.27+/-0.01, 0.27+/-0.02, 0.3+/-0.01% (p<0.05)), respectively. Ultimate tensile stress (UTS) was greater in 10-min treated pericardium than in untreated tissue: 38.46+/-11.75 versus 22.17+/-8.30 MPa (p<0.05) respectively. Strain at rupture was greater in the 6-month group (30.62+/-2.54%) than for untreated and 10-, 30- and 60-min GLUT immersion 16.3+/-0.73, 21.85+/-0.75, 20.12+/-1.04 and 18.87+/-0.86% (p<0.05), respectively. Fatigue testing showed an increased length after five and 10 min, and six months, with a lengthening of 14.66, 12.53, 7.66%, respectively compared with 3.5% for untreated tissue (p<0.05). There were three failures in the untreated group (n = 5), none in the 5- and 10-min groups, and one in the 6-month group (p<0.05). CONCLUSION: Brief immersion of human pericardial tissue in 0.625% glutaraldehyde reduces the tissue's stiffness and improves its durability for use in cardiac surgery.

Chronic respiratory symptoms in children and adults living along streets with high traffic density.

OBJECTIVES: To investigate if the population living along streets with high traffic density has a higher prevalence of chronic respiratory symptoms. METHODS: A sample of 673 adults and 106 children (0-15 years), living along busy traffic streets in the city of Haarlem was compared with a control sample of 812 adults and 185 children living along quiet streets. Exposed and control streets were selected on the basis of model calculations of NO2 concentrations. A postal questionnaire containing questions about respiratory symptoms and several potential confounders was used to collect information from the study subjects. RESULTS: After adjustment for potential confounders, children living along busy streets were found to have a higher prevalence of most respiratory symptoms than children living along quiet streets. Adjusted odds ratios were significant for wheeze and for respiratory medication used. Risk ratios were higher for girls than for boys, with significant adjusted odds ratios between 2.9 and 15.8 for girls. In adults, only mild dyspnoea was more often reported by subjects living along streets with high traffic density. CONCLUSIONS: The results suggest that living along busy streets increases the risk of developing chronic respiratory symptoms in children.

Models of human exposure based on environmental monitoring.

The relevant exposure to environmental pollutants or relevant confounders can virtually never be measured directly in sufficient detail in a sufficient number of people included in an epidemiological study. Instead, surrogate indicators of exposure are used that are implicitly or explicitly linked by (conceptual) models to the 'relevant exposure'. Using specified indices (e.g., the coefficient of alienation and forecasting efficiency), the models of different forms can be compared and tested in special investigations. This can evaluate the criterion validity of the model through analysis of the agreement between the model estimates, based on measured surrogate indicators of the exposure, and the actual exposure. The perspective on the construct under study may further change the validity of the exposure indicator. Therefore, sub-studies evaluating the quality of exposure indicators should be considered as integral part of any study in environmental epidemiology, preferably as a pre-study or pilot study.

Acute effects of ambient ozone on pulmonary function of children in The Netherlands.

In the spring and summer of 1989 an epidemiologic study was conducted to evaluate the acute effects of photochemical air pollution episodes on pulmonary function of children living in three nonindustrial towns in the Netherlands. Spirometry was performed repeatedly in the schools of the children, mostly during the morning hours. Data from 533 children having more than four valid pulmonary function tests were included in the analyses. The association between previous-day ambient ozone concentration and pulmonary function was evaluated, using individual linear regression analysis and subsequent evaluation of the distribution of individual regression coefficients. One hour maximum ambient ozone concentrations frequently exceeded 160 micrograms/m3 but were all lower than the Dutch Air Quality Guideline of 240 micrograms/m3 for all three populations. Significant negative associations of previous-day ambient ozone with FVC, FEV1, peak expiratory flow (PEF), and maximal midexpiratory flow (MMEF) were observed. There were indications of systematic differences in responses among the children. Children with chronic respiratory symptoms did not have a stronger response than children without these symptoms.

Assessing future trends in indoor air quality.

Several national and international health organizations have derived concentration levels below which adverse effects on men are not expected or levels below which the excess risk for individuals is less than a specified value. For every priority pollutant indoor concentrations below this limit are considered "healthy." The percentage of Dutch homes exceeding such a limit is taken as a measure of indoor air quality for that component. The present and future indoor air quality of the Dutch housing stock is described for fourteen air pollutants. The highest percentages are scored by radon, environmental tobacco smoke, nitrogen dioxide from unvented combustion, and the potential presence of housedust mite and mould allergen in damp houses. Although the trend for all priority pollutants is downward the most serious ones remain high in the coming decades if no additional measures will be instituted.

Errors in exposure measures.

Errors in exposure measures reduce the power in statistical tests in health effect studies, and also bias the estimate of the magnitude of the effect of exposure on health. Several types of error in commonly used exposure measures are described. To study how these errors in exposure measures may obscure exposure-response relationships, an imaginary data set was generated, with (indoor) exposure to nitrogen dioxide and fine particles in relation to pulmonary function as an example. With this data set, the effect of different types of errors in the exposure measures were simulated. The simulation indicated that a serious under- or overestimation of the magnitude of the health effect can occur due to errors in the exposure measures. The bias was more pronounced for errors in strong than in weak determinants of the health effects.

Indoor air pollution and its effect on pulmonary function of adult non-smoking women: I. Exposure estimates for nitrogen dioxide and passive smoking.

The potential effects of indoor NO2 and tobacco smoke on the respiratory system were studied using pulmonary function data from a longitudinal study. In 1982, NO2 was measured in 163 homes of non-smoking adult women and detailed information on smoking inside the house was gathered over the period 1965-1982. Personal exposure to NO2 was calculated from the measured levels and the activity pattern of the study population (range 11-139 micrograms NO2/m3). Historical exposure was estimated using regression models of NO2 on house characteristics. It is shown that estimation of historical exposure to indoor NO2 on the basis of house characteristics only is, at present, too inaccurate for use in epidemiological studies. Actual measurement of NO2 is unavoidable for exposure assessment in health effect studies of indoor exposure to NO2.

The relationship between indoor nitrogen dioxide concentration levels and personal exposure: a pilot study.

A small, personal monitoring study was performed in a subpopulation (14 families) of a case-control study on the relationship between indoor nitrogen-dioxide exposure and respiratory diseases of schoolchildren. Mothers, schoolchildren and pre-schoolchildren were asked to carry duplicate Palmes diffusion tubes during one week. Simultaneously nitrogen-dioxide concentrations were measured in the kitchen, living room, bedroom, outdoors and--for a few participants--at school and at work. Information on time activity patterns was gathered by means of a self administered diary. Several models for estimating exposure were constructed and tested against measured exposure. The personal exposure of the participants could well be explained by models containing indoor concentrations. Models with time-weighted average concentrations did not explain personal exposure better than models containing indoor concentrations. A calculated time-weighted average exposure was found to underestimate measured personal exposure by an average 20%, probably because the average concentration in a location does not necessarily reflect the actual exposure in that location. Personal exposure of mothers and children was very similar and highly correlated, indicating that the personal exposure of the mother might be a reasonable estimate for the exposure of the child.

Detecting indoor CO exposure by measuring CO in exhaled breath.

CO levels in exhaled breath were measured in 29 residents of flats, equipped with a flueless geiser (an instantaneous gas-fired water heater). The flats were selected because they had a geiser with a CO concentration of more than 250 parts per million in its flue gases. Small, but in some cases statistically significant increases in CO levels in exhaled breath were found in both smokers and non smokers, and after periods of cooking and dishwashing when the geisers had been used. Calculated COHb levels remained well below 2.5% for non smokers, but were generally higher for smokers.

Indoor air pollution by carbon monoxide and nitrogen oxides.

The results of an exploratory survey of indoor levels of carbon monoxide and nitrogen dioxide from gas-fired cooking and waterheating appliances in the Dutch cities of Arnhem and Enschede in the fall of 1980 are reported. Measurements were carried out electrochemically (Ecolyzer 2000) or with Draeger tubes in the case of CO and with Palmes diffusion tubes (5 to 8 days exposure) in the case of NO2. For CO, in 18% (27%) of the homes visited the limit of 600 (300) ppm in the flue gases was exceeded, whereas the Dutch Installation Code Standard of 50 ppm CO in room air was exceeded in 17% of the homes. The arithmetic mean value of the NO2 concentration in 286 homes was 118 micrograms/m3 with a range of 35 to 472 micrograms/m3. The corresponding figures for living rooms were 58 and 35 to 346 micrograms/m3, respectively. Outdoor NO2 concentrations were 2 to 3 times lower than indoor concentrations.

The feasibility of using lead in hair concentration in monitoring environmental exposure in children.

The feasibility of lead in hair as an indicator of lead exposure has been compared to that of lead in blood and zinc protoporphyrin in blood levels in 1--3-year-old children living within 1 km of a lead smelter. Lead exposure was measured as lead in house dust, outdoor and indoor lead in air concentrations, outdoor and indoor lead depositions, and subjective assessment of indoor dustiness. Lead in blood ranged from 51-353 microgram/l and lead in hair from 0.8-114 microgram/g. It can be concluded that within the range of environmental exposure studied, and for the age group concerned, measurement of lead in blood and of the zinc protoporphyrin in blood levels appear to be better biological parameters to assess both total environmental exposure and health risk than measurement of lead in hair level alone.