Effect of Grandmaternal Smoking on Body Size and Proportions at Birth.

Many long-term adverse effects of smoking during pregnancy are known. Increasingly, adverse effects in the grandchild after grandmaternal smoking during pregnancy are reported. We explored this in a birth cohort of 24,000 grandmother-mother-child triads identified from the Finnish Medical Birth Register in 1991-2016. Multiple logistic regression was used to analyze the association between any smoking during pregnancy by both grandmother and mother, or only grandmother or mother on adverse birth outcomes. No smoking by neither grandmother nor mother was used as the reference. As endpoints, preterm birth, low birth weight, small for gestational age (birth weight, birth length, head circumference), and body proportionality (low ponderal index, high brain-to-body ratio, high head-to-length ratio) were included. Smoking by both grandmother and mother was consistently associated with higher risks than smoking only by the mother. Birth length and weight were especially sensitive to (grand)maternal smoking. In conclusion, the combined effect of grandmaternal and maternal smoking is associated with higher risks than only maternal smoking.

Effects of maternal smoking on body size and proportions at birth: a register-based cohort study of 1.4 million births.

OBJECTIVES: The aim of our work was to analyse the effect of maternal smoking on body size and body proportions of newborns when the mother had smoked only during the first trimester, in comparison with continued smoking after the first trimester. Furthermore, we have evaluated how growth restriction associated with maternal smoking contributes to changes in body proportions. DESIGN: Register-based cohort study SETTING: Maternal Exposure (MATEX) cohort identified from the Finnish Medical Birth Register. PARTICIPANTS: Singleton births without congenital anomalies and missing data (1.38 million) from 1 January 1991 to 31 December 2016. METHODS: Logistic regression was used to quantify the effect of maternal smoking, stratified by the maternal smoking status. OUTCOME MEASURES: Body proportions indicated by low brain-to-body ratio (defined as <10th percentile); high ponderal index and high head-to-length ratio (defined as >90th percentile); small body size for gestational age at birth (defined as weight, length or head circumference <10th percentile) and preterm birth (<37 weeks) and low birth weight (2500 g). RESULTS: Continued smoking after the first trimester was associated with high ponderal index (OR 1.26, 95% CI 1.23 to 1.28), low brain-to-body ratio (1.11, 1.07-1.15) and high head-to-length ratio (1.22, 1.19-1.26), corresponding with absolute risks of 22%, 10% and 19%, respectively). The effects were slightly lower when smoking had been quit during the first trimester. Similar effects were seen for the body size variables and low birth weight. Preterm birth was not associated with smoking only during first trimester. CONCLUSIONS: Maternal smoking, independent of smoking duration during pregnancy, was associated with abnormal body proportions resulting from larger reduction of length and head circumference in comparison to weight. The effects of having quit smoking during the first trimester and having continued smoking after the first trimester were similar, suggesting the importance of early pregnancy as a sensitive exposure window.

Chained Risk Assessment for Life-Long Disease Burden of Early Exposures - Demonstration of Concept Using Prenatal Maternal Smoking.

Traditional risk factors and environmental exposures only explain less than half of the disease burden. The developmental origin of the health and disease (DOHaD) concept proposes that prenatal and early postnatal exposures increase disease susceptibility throughout life. The aim of this work is to demonstrate the application of the DOHaD concept in a chained risk assessment and to provide an estimate of later in life burden of disease related to maternal smoking. We conducted three systematic literature searches for meta-analysis and reviewed the literature reporting meta-analyses of long-term health outcomes associated with maternal smoking and intermediate risk factors (preterm birth, low birth weight, childhood overweight). In the chained model the three selected risk factors explained an additional 2% (34,000 DALY) of the total non-communicable disease burden (1.4 million DALY) in 2017. Being overweight in childhood was the most important risk factor (28,000 DALY). Maternal smoking was directly associated with 170 DALY and indirectly via the three intermediate risk factors 1000 DALY (1200 DALY in total). The results confirm the potential to explain a previously unattributed part of the non-communicable diseases by the DOHAD concept. It is likely that relevant outcomes are missing, resulting in an underestimation of disease burden.

Smoking during pregnancy in Finland - Trends in the MATEX cohort.

Aims: In Finland, smoking rates in the general population are decreasing due to increased awareness of the adverse effects and tightened tobacco legislation. However, previous studies have shown that smoking in pregnant Finnish women remained as high as in the general Finnish female population at around 15% in 2010. Our aim was to describe temporal and spatial trends in smoking behaviour, and determinants of changes in smoking behaviour between first and second pregnancy. Methods: Self-reported smoking from the Finnish Medical Birth Register covered the years 1991-2015 (N=1,435,009). The association of maternal age and socioeconomic status with smoking rate was analysed. Spatial trends were assessed at municipality level. Results: The overall smoking rate during early pregnancy remained fairly stable at around 15% from 1991 to 2015, but increased in teenage and young women below 25 years of age. The mean smoking rate (36%) was higher in these age groups than in older pregnant women (11%). Through the study period the smoking rate remained higher in blue collar workers compared with higher socioeconomic groups. Between the first and second child, on average only 4% of women started to smoke and 41% quitted. Smoking rates developed less favourably in Eastern Finland. Conclusions: The observed increase in smoking rate during pregnancy in teenage and young women is concerning. Pregnancy is a trigger point for smoking cessation in a big fraction of pregnant women. More studies are needed to explain the opposite trends of smoking rates in Northern and Western Finland compared with Eastern Finland.

Methods of health risk and impact assessment at industrially contaminated sites: a systematic review.

BACKGROUND: this paper is based upon work from COST Action ICSHNet. Industrially contaminated sites (ICSs) are a serious problem worldwide and there is growing concern about their impacts on the environment and public health. Health risk assessment methods are used to characterize and quantify the health impacts on nearby populations and to guide public health interventions. However, heterogeneous methods and inconsistent reporting practices compromise comparability risk and impact estimates. OBJECTIVES: to review the literature on assessment of the adverse health effects of ICSs. Specifically, we: - collect published, peer-reviewed literature addressing health assessment of ICSs; - identified and evaluated the methods and tools for the assessment of health impacts related to ICSs; - analysed the methods and tools used in different conditions; - discussed the strengths and weaknesses of the identified approaches; - presented an up-to-date understanding of the available health risk and impact assessment in ICSs. In addition, the terminologies were described and harmonization was proposed. METHODS: we systematically searched PubMed and Web of Science to identify peer-reviewed reviews and original studies from January 1989 to December 2017. We used a qualitative approach for analysing the different elements (type of ICSs, Country of research, active years of working, distance from sources, pollutants, affected population, methods and tools, health outcomes, main founding, method stage, dose-response assessment, risk characterization) of included studies. We divided risk assessment methods used in the papers into four stages: semi-quantitative, quantitative, health impact, and health burden stage. RESULTS: a total of 92 relevant original papers at ICSs were found and analysed. In current practice, the health risks have been characterized mainly as hazard quotients or hazard indexes (23 studies), and as cancer risk probabilities (60 studies). Only 8 studies estimated the number of cases and one study evaluated years of life lost. CONCLUSION: hazard quotients and cancer probabilities are suitable for semi-quantitative and quantitative personal risk estimation, respectively. More comparable risk characterization on public health level requires specificity on the type of outcome and corresponding number of cases. Such data is needed for prioritization of action at low to medium risk sites. We found limited amount of studies that have quantified the health impact at industrially contaminated sites. Most of the studies have used semi-quantitative risk characterization approaches and the adopted methods are mostly of toxicological origin, while epidemiological analysis is almost lacking. There is a need to improve quantitative risk assessment and include health impact and environmental burden of disease assessments at ICSs.

The MATEX cohort - a Finnish population register birth cohort to study health effects of prenatal exposures.

BACKGROUND: The prevalence of chronic diseases, such as immune, neurobehavioral, and metabolic disorders has increased in recent decades. According to the concept of Developmental Origin of Health and Disease (DOHaD), developmental factors associated with environmental exposures and maternal lifestyle choices may partly explain the observed increase. Register-based epidemiology is a prime tool to investigate the effects of prenatal exposures over the whole life course. Our aim is to establish a Finnish register-based birth cohort, which can be used to investigate various (prenatal) exposures and their effects during the whole life course with first analyses focusing on maternal smoking and air pollution. In this paper we (i) review previous studies to identify knowledge gaps and overlaps available for cross-validation, (ii) lay out the MATEX study plan for register linkages, and (iii) analyse the study power of the baseline MATEX cohort for selected endpoints identified from the international literature. METHODS/DESIGN: The MATEX cohort is a fully register-based cohort identified from the Finnish Medical Birth Register (MBR) (1987-2015). Information from the MBR will be linked with other Finnish health registers and the population register to link the cohort with air quality data. Epidemiological analyses will be conducted for maternal smoking and air pollution and a range of health endpoints. DISCUSSION: The MATEX cohort consists of 1.75 million mother-child pairs with a maximum follow up time of 29 years. This makes the cohort big enough to reach sufficient statistical power to investigate rare outcomes, such as birth anomalies, childhood cancers, and sudden infant death syndrome (SIDS). The linkage between different registers allows for an extension of the scope of the cohort and a follow up from the prenatal period to decades later in life.

Maternal Smoking and the Risk of Cancer in Early Life - A Meta-Analysis.

BACKGROUND: In spite of the well-known harmful effects on the fetus, many women continue smoking during pregnancy. Smoking as an important source of toxic chemicals may contribute to the developmental origin of diseases. OBJECTIVES: The aim of this work was to pursue the possible association between maternal smoking and cancer in early life. Specifically, we wanted to identify the associated early life cancer types, and to quantify the associations. METHODS: In a systematic literature search 825 articles were identified in PubMed and Web of Science, and 55 more through the reference lists. Of these 62 fulfilled the criteria for inclusion in meta-analyses. Using Mantel-Haenszel or DerSimonian and Laird method, depending on heterogeneity of the studies, pooled estimates and 95% confidence intervals for eight cancer types were calculated. RESULTS: Smoking during pregnancy was associated with an increased risk for for brain and central nervous system tumors (OR = 1.09; 95% CI = 1.02-1.17). Although the risk for lymphoma was also associated (OR = 1.21; 95% CI = 1.05-1.34), it did not hold up in subgroup analyses. Leukemia was not found to be associated with maternal smoking. Five other cancer types (bone, soft tissue, renal, hepatic, and germ cell cancer) were also examined, but the number of studies was too limited to exclude the possibility of maternal smoking as a risk factor for cancer in offspring. CONCLUSIONS: According to our meta-analyses, maternal smoking is associated with nervous system cancers, but not with leukemia in early life. Confirming or rejecting associations of maternal smoking with lymphoma and the five other cancer types requires further studies.

Reducing burden of disease from residential indoor air exposures in Europe (HEALTHVENT project).

BACKGROUND: The annual burden of disease caused indoor air pollution, including polluted outdoor air used to ventilate indoor spaces, is estimated to correspond to a loss of over 2 million healthy life years in the European Union (EU). Based on measurements of the European Environment Agency (EEA), approximately 90 % of EU citizens live in areas where the World Health Organization (WHO) guidelines for air quality of particulate matter sized < 2.5 mm (PM2.5) are not met. Since sources of pollution reside in both indoor and outdoor air, selecting the most appropriate ventilation strategy is not a simple and straightforward task. METHODS: A framework for developing European health-based ventilation guidelines was created in 2010-2013 in the EU-funded HEALTHVENT project. As a part of the project, the potential efficiency of control policies to health effects caused by residential indoor exposures of fine particulate matter (PM2.5), outdoor bioaerosols, volatile organic compounds (VOC), carbon oxide (CO) radon and dampness was estimated. The analysis was based on scenario comparison, using an outdoor-indoor mass-balance model and varying the ventilation rates. Health effects were estimated with burden of diseases (BoD) calculations taking into account asthma, cardiovascular (CV) diseases, acute toxication, respiratory infections, lung cancer and chronic obstructive pulmonary disease (COPD). RESULTS: The quantitative comparison of three main policy approaches, (i) optimising ventilation rates only; (ii) filtration of outdoor air; and (iii) indoor source control, showed that all three approaches are able to provide substantial reductions in the health risks, varying from approximately 20 % to 44 %, corresponding to 400 000 and 900 000 saved healthy life years in EU-26. PM2.5 caused majority of the health effects in all included countries, but the importance of the other pollutants varied by country. CONCLUSIONS: The present modelling shows, that combination of controlling the indoor air sources and selecting appropriate ventilation rate was the most effective to reduce health risks. If indoor sources cannot be removed or their emissions cannot be limited to an accepted level, ventilation needs to be increased to remove remaining pollutants. In these cases filtration of outdoor air may be needed to prevent increase of health risks.

Environmental Asthma Reduction Potential Estimates for Selected Mitigation Actions in Finland Using a Life Table Approach.

AIMS: To quantify the reduction potential of asthma in Finland achievable by adjusting exposures to selected environmental factors. METHODS: A life table model for the Finnish population for 1986-2040 was developed and Years Lived with Disability caused by asthma and attributable to the following selected exposures were estimated: tobacco smoke (smoking and second hand tobacco smoke), ambient fine particles, indoor dampness and mould, and pets. RESULTS: At baseline (2011) about 25% of the total asthma burden was attributable to the selected exposures. Banning tobacco was the most efficient mitigation action, leading to 6% reduction of the asthma burden. A 50% reduction in exposure to dampness and mould as well as a doubling in exposure to pets lead each to a 2% reduction. Ban of urban small scale wood combustion, chosen as a mitigation action to reduce exposure to fine particles, leads to a reduction of less than 1% of the total asthma burden. Combination of the most efficient mitigation actions reduces the total asthma burden by 10%. A more feasible combination of mitigation actions leads to 6% reduction of the asthma burden. CONCLUSIONS: The adjustment of environmental exposures can reduce the asthma burden in Finland by up to 10%.

Personal day-time exposure to ultrafine particles in different microenvironments.

In order to assess the personal exposure to ultrafine particles (UFP) during individual day-time activities and to investigate the impact of different microenvironments on exposure, we measured personal exposure to particle number concentrations (PNC), a surrogate for UFP, among 112 non-smoking participants in Augsburg, Germany over a nearly two-year period from March 2007 to December 2008. We obtained 337 personal PNC measurements from 112 participants together with dairies of their activities and locations. The measurements lasted on average 5.5h and contained on average 330 observations. In addition, ambient PNC were measured at an urban background stationary monitoring site. Personal PNC were highly variable between measurements (IQR of mean: 11780-24650cm(-3)) and also within a single measurement. Outdoor personal PNC in traffic environments were about two times higher than in non-traffic environments. Higher indoor personal PNC were associated with activities like cooking, being in a bistro or exposure to passive smoking. Overall, personal and stationary PNC were weakly to moderately correlated (r<0.41). Personal PNC were much higher than stationary PNC in traffic (ratio: 1.5), when shopping (ratio: 2.4), and indoors with water vapor (ratio: 2.5). Additive mixed models were applied to predict personal PNC by participants' activities and locations. Traffic microenvironments were significant determinants for outdoor personal PNC. Being in a bistro, passive smoking, and cooking contributed significantly to an increased indoor personal PNC.

Parameter and model uncertainty in a life-table model for fine particles (PM2.5): a statistical modeling study.

BACKGROUND: The estimation of health impacts involves often uncertain input variables and assumptions which have to be incorporated into the model structure. These uncertainties may have significant effects on the results obtained with model, and, thus, on decision making. Fine particles (PM2.5) are believed to cause major health impacts, and, consequently, uncertainties in their health impact assessment have clear relevance to policy-making. We studied the effects of various uncertain input variables by building a life-table model for fine particles. METHODS: Life-expectancy of the Helsinki metropolitan area population and the change in life-expectancy due to fine particle exposures were predicted using a life-table model. A number of parameter and model uncertainties were estimated. Sensitivity analysis for input variables was performed by calculating rank-order correlations between input and output variables. The studied model uncertainties were (i) plausibility of mortality outcomes and (ii) lag, and parameter uncertainties (iii) exposure-response coefficients for different mortality outcomes, and (iv) exposure estimates for different age groups. The monetary value of the years-of-life-lost and the relative importance of the uncertainties related to monetary valuation were predicted to compare the relative importance of the monetary valuation on the health effect uncertainties. RESULTS: The magnitude of the health effects costs depended mostly on discount rate, exposure-response coefficient, and plausibility of the cardiopulmonary mortality. Other mortality outcomes (lung cancer, other non-accidental and infant mortality) and lag had only minor impact on the output. The results highlight the importance of the uncertainties associated with cardiopulmonary mortality in the fine particle impact assessment when compared with other uncertainties. CONCLUSION: When estimating life-expectancy, the estimates used for cardiopulmonary exposure-response coefficient, discount rate, and plausibility require careful assessment, while complicated lag estimates can be omitted without this having any major effect on the results.

Personal carbon monoxide exposure levels: contribution of local sources to exposures and microenvironment concentrations in Milan.

In the framework of the EXPOLIS study in Milan, Italy, 48-h carbon monoxide (CO) exposures of 50 office workers were monitored over a 1-year period. In this work, the exposures were assessed for different averaging times and were compared with simultaneous ambient fixed-site concentrations. The effect of gas cooking and smoking and different methods of commuting on the microenvironment and exposure levels of CO were investigated. During the sampling the subjects completed a time-microenvironment-activity diary differentiating 11 microenvironments and three exposure influencing activities: gas cooking, smoking and commuting. After sampling, all exposure and time allocation data were stored in a relational database that is used in data analyses. Ambient 48-h and maximum 8-h distributions were similar compared to the respective personal exposures. The maximum 1-h personal exposures were much higher than the maximum 8-h exposures. The maximum 1-h exposures were as well higher than the corresponding ambient distribution. These findings indicate that high short-term exposures were not reflected in ambient monitoring data nor by long-term exposures. When gas cooking or smoking was present, the indoor levels at "home-" and in "other indoor" microenvironments were higher than without their presence. Compared with ambient data, the latter source was the most affective to increase the indoor levels. Exposure during commuting was higher than in all other microenvironments; the highest daily exposure contribution was found during "car/taxi" driving. Most of the CO exposure is acquired in indoor microenvironments. For the indoor microenvironments, ambient CO was the weakest predictor for "home indoor" concentrations, where the subjects spent most of their time, and the strongest for "other indoor" concentrations, where the smallest fraction of the time was spent. Of the main indoor sources, gas cooking, on average, significantly raised the indoor exposure concentrations for 45 min and tobacco smoking for 30 min. The highest exposure levels were experienced in street commuting. Personal exposures were well predicted, but 1-h maximum personal exposures were poorly predicted, by respective ambient air quality data. By the use of time-activity diaries, ETS exposure at the workplaces were probably misclassified due to differences in awareness to tobacco smoke between smokers and nonsmokers.

EXPOLIS simulation model: PM2.5 application and comparison with measurements in Helsinki.

PM(2.5) exposure distributions of adult Helsinki citizens were simulated using a probabilistic simulation framework. Simulation results were compared to corresponding personal exposure distributions measured in the EXPOLIS study in Helsinki. The simpler models 1 and 2 (with two and three microenvironments, respectively) predict the general outline of the exposure distributions reasonably well. Compared to the observed exposure distribution, the mean is underestimated by less than 3 microg m(-3) (20%) and the standard deviation by 23-35%. In the improved simulation models (3 and 4), the environmental tobacco smoke (ETS)-exposed subjects are excluded, the time-activity models of working and nonworking subpopulations are modeled separately, and the correlations of input concentration and time fraction variables have been accounted for. The output of these models was very close to the observed distributions; the differences in the means were less than 0.1 microg m(-3) and the differences in standard deviation less than 1%. We conclude that when the required input data are available or can be reliably estimated, the target population PM(2.5) exposure distributions can be predicted accurately enough for most practical purposes using this kind of a microenvironment model.