While there is a large variation of prevalence of asthma symptoms worldwide, what we do know is that it is on the rise in developing countries. However, there are few studies on allergens, moulds and mycotoxin exposure in schools in tropical countries. The aims were to measure selected fungal DNA, furry pet allergens and mycotoxins in dust samples from schools in Malaysia and to study associations with pupils' respiratory health effects. Eight secondary schools and 32 classrooms in Johor Bahru, Malaysia were randomly selected. A questionnaire with standardized questions was used for health assessment in 15 randomly selected pupils from each class. The school buildings were inspected and both indoor and outdoor climate were measured. Dust samples were collected by cotton swabs and Petri dishes for fungal DNA, mycotoxins and allergens analysis. The participation rate was 96% (462/480 invited pupils), with a mean age of 14 yr (range 14-16). The pupils mostly reported daytime breathlessness (41%), parental asthma or allergy (22%), pollen or pet allergy (21%) and doctor-diagnosed asthma (13%) but rarely reported night-time breathlessness (7%), asthma in the last 12 months (3%), medication for asthma (4%) or smoking (5%). The inspection showed that no school had any mechanical ventilation system, but all classrooms had openable windows that were kept open during lectures. The mean building age was 16 yr (range 3-40) and the mean indoor and outdoor CO(2) levels were 492 ppm and 408 ppm, respectively. The mean values of indoor and outdoor temperature and relative humidity were the same, 29°C and 70% respectively. In cotton swab dust samples, the Geometric Mean (GM) value for total fungal DNA and Aspergillus/Penicillium (Asp/Pen) DNA in swab samples (Cell Equivalents (CE)/m(2)) was 5.7*10(8) and 0.5*10(8), respectively. The arithmetic mean (CE/m(2)) for Aspergillus versicolor DNA was 8780, Stachybotrys chartarum DNA was 26 and Streptomyces DNA was 893. The arithmetic means (pg/m(2)) for the mycotoxins sterigmatocystin and verrucarol were 2547 and 17, respectively. In Petri dish dust samples, the GM value for total fungal DNA and Asp/Pen DNA (CE/m(2) per day) was 9.2*10(6) and 1.6*10(6), respectively. The arithmetic mean (CE/m(2) per day) for A. versicolor DNA was 1478, S. chartarum DNA was 105 and Streptomyces DNA was 1271, respectively. The GM value for cat (Fel d1) allergen was 5.9 ng/m(2) per day. There were positive associations between A. versicolor DNA, wheeze and daytime breathlessness and between Streptomyces DNA and doctor-diagnosed asthma. However, the associations were inverse between S. chartarum DNA and daytime breathlessness and between verrucarol and daytime breathlessness. In conclusion, fungal DNA and cat allergen contamination were common in schools from Malaysia and there was a high prevalence of respiratory symptoms among pupils. Moreover, there were associations between levels of some fungal DNA and reported respiratory health in the pupils.

We investigated if maternal body burdens of perfluoroalkyl acids (PFAAs) at the time of delivery are associated with birth outcome and if early life exposure (in utero/nursing) is associated with early childhood growth and weight gain. Maternal PFAA body burdens were estimated by analysis of serum samples from mothers living in Uppsala County, Sweden (POPUP), sampled three weeks after delivery between 1996 and 2011. Data on child length and weight were collected from medical records and converted into standard deviation scores (SDS). Multiple linear regression models with appropriate covariates were used to analyze associations between maternal PFAA levels and birth outcomes (n=381). After birth Generalized Least Squares models were used to analyze associations between maternal PFAA and child growth (n=200). Inverse associations were found between maternal levels of perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA), and birth weight SDS with a change of -0.10 to -0.18 weight SDS for an inter-quartile range (IQR) increase in ng/g PFAA. After birth, weight and length SDS were not significantly associated with maternal PFAA. However, BMI SDS was significantly associated with PFOA, PFNA, and PFHxS at 3 and 4years of age, and with PFOS at 4 and 5years of age. If causal, these associations suggest that PFAA affects fetal and childhood body development in different directions.

BackgroundThe knowledge of the impact of cardiovascular risk factors at different ages has mainly been based on different studies performed at different ages. This study aimed to investigate the change in impact of traditional cardiovascular risk factors over the aging process in subjects followed for 4 decades.Methods and ResultsIn the ULSAM (Uppsala Longitudinal Study of Adult Men) study, 2322 men originally investigated in 1970 to 1974 have been followed regarding cardiovascular diseases until the end of 2013. This cohort has been investigated physically at ages 50, 60, 70, 77, and 82 years regarding body mass index, low‐density lipoprotein‐ and high‐density lipoprotein‐cholesterol, triglycerides, systolic blood pressure and diastolic blood pressure, fasting glucose, and smoking. These data were used to model the interactions between risk factors and age regarding incident myocardial infarction (n=540), ischemic stroke (n=343), or heart failure (n=397). Significant interactions were observed between age and the set of traditional risk factors regarding all 3 outcomes (P<0.05 for all). Generally, a decline in the rate ratios was seen with aging for most risk factors, being most pronounced for body mass index regarding myocardial infarction and for systolic blood pressure regarding ischemic stroke and heart failure. However, low‐density lipoprotein‐cholesterol was significantly related to incident myocardial infarction, whereas both body mass index and fasting glucose were significantly related to incident heart failure also at a high age.ConclusionsUsing a longitudinal design in middle‐aged men spanning 4 decades showed that the impact of traditional cardiovascular risk factors generally declined with aging. However, some of the risk factors remained significantly associated with incident cardiovascular disease also at old age.

39Age-related changes in DNA methylation have been observed in many cross-sectional studies, 40 but longitudinal evidence is still very limited. Here, we aimed to characterize longitudinal age-41 related methylation patterns (Illumina HumanMethylation450 array) using 1011 blood samples 42 collected from 385 old Swedish twins (mean age of 69 at baseline) up to five times over 20 years. 43We identified 1316 age-associated methylation sites (p<1.3×10 -7 ) using a longitudinal 44 epigenome-wide association study design. We measured how estimated cellular compositions 45 changed with age and how much they confounded the age effect. We validated the results in two 46 independent longitudinal cohorts, where 118 CpGs were replicated in PIVUS (p<3.9×10 ). Functional annotation of age-associated CpGs showed 48 enrichment in CCCTC-binding factor (CTCF) and other unannotated transcription factor binding 49 sites. We further investigated genetic influences on methylation (methylation quantitative trait 50 loci) and found no interaction between age and genetic effects in the 1316 age-associated CpGs. 51Moreover, in the same CpGs, methylation differences within twin pairs increased over time, 52where monozygotic twins had smaller intra-pair differences than dizygotic twins. We show that 53 age-related methylation changes persist in a longitudinal perspective, and are fairly stable 54 across cohorts. Moreover, the changes are under genetic influence, although this effect is 55 independent of age. In addition, inter-individual methylation variations increase over time, 56 especially in age-associated CpGs, indicating the increase of environmental contributions on 57 DNA methylation with age. 58

DNA methylation-based estimation of "biological age" per Horvath was associated with incident cardiovascular disease.