Toxicity and elemental composition of particulate matter from outdoor and indoor air of elementary schools in Munich, Germany

Outdoor particulate matter (PM(10)) is associated with detrimental health effects. However, individual PM(10) exposure occurs mostly indoors. We therefore compared the toxic effects of classroom, outdoor, and residential PM(10). Indoor and outdoor PM(10) was collected from six schools in Munich during teaching hours and in six homes. Particles were analyzed by scanning electron microscopy and X-ray spectroscopy (EDX). Toxicity was evaluated in human primary keratinocytes, lung epithelial cells and after metabolic activation by several human cytochromes P450. We found that PM(10) concentrations during teaching hours were 5.6-times higher than outdoors (117 ± 48 μg/m(3) vs. 21 ± 15 μg/m(3), P < 0.001). Compared to outdoors, indoor PM contained more silicate (36% of particle number), organic (29%, probably originating from human skin), and Ca-carbonate particles (12%, probably originating from paper). Outdoor PM contained more Ca-sulfate particles (38%). Indoor PM at 6 μg/cm(2) (10 μg/ml) caused toxicity in keratinocytes and in cells expressing CYP2B6 and CYP3A4. Toxicity by CYP2B6 was abolished with the reactive oxygen species scavenger N-acetylcysteine. We concluded that outdoor PM(10) and indoor PM(10) from homes were devoid of toxicity. Indoor PM(10) was elevated, chemically different and toxicologically more active than outdoor PM(10). Whether the effects translate into a significant health risk needs to be determined. Until then, we suggest better ventilation as a sensible option.

PRACTICAL IMPLICATIONS

Indoor air PM(10) on an equal weight base is toxicologically more active than outdoor PM(10). In addition, indoor PM(10) concentrations are about six times higher than outdoor air. Thus, ventilation of classrooms with outdoor air will improve air quality and is likely to provide a health benefit. It is also easier than cleaning PM(10) from indoor air, which has proven to be tedious.

Determination of bisphenol a in urine from mother-child pairs-results from the duisburg birth cohort study, Germany

Bisphenol A (BPA) may alter endocrine functions, and human exposure is widespread. In the Duisburg birth cohort study the influence of several contaminants was examined on the neuropsychological and pubertal development of children. This study reports the biomonitoring results on BPA within the 6-yr follow-up study (children's age 6-8 yr). Total BPA and free (unconjugated) BPA concentrations in 208 urine samples of 104 mother-child pairs were measured. For quality control, total BPA was analyzed by two independent laboratories. BPA was detected in all urine samples, while free BPA was observed above the limit of quantification (LOQ) in only 33 samples. Total BPA concentrations were significantly associated between the two laboratories. BPA concentrations (median; range) tended to be higher in children than in mothers but the difference was not significant. Total BPA levels in children and mothers correlated at low levels but significantly to each other. Multivariate linear regression analysis revealed positive associations between creatinine and the BPA concentrations and a negative association with German nationality (mothers only). Evidence indicates that BPA exposure is omnipresent but levels in mother-child pairs are low. Only small amounts (less than 16%) were detectable as free (unconjugated) BPA. Analytical reliability is high even at such low levels, provided that external contamination is minimized.

High concentrations of cadmium, cerium and lanthanum in indoor air due to environmental tobacco smoke

BACKGROUND

Environmental tobacco smoke (ETS) is one of the most important sources for indoor air pollution and a substantial threat to human health, but data on the concentrations of the trace metals cerium (Ce) and lanthanum (La) in context with ETS exposure are scarce. Therefore the aim of our study was to quantify Ce and La concentrations in indoor air with high ETS load.

METHODS

In two subsequent investigations Ce, La and cadmium (Cd) in 3 smokers' (11 samples) and 7 non-smokers' (28 samples) households as well as in 28 hospitality venues in Southern Germany were analysed. Active sampling of indoor air was conducted continuously for seven days in every season in the smokers' and non-smokers' residences, and for 4h during the main visiting hours in the hospitality venues (restaurants, pubs, and discotheques).

RESULTS

In terms of residences median levels of Cd were 0.1 ng/m(3) for non-smokers' and 0.8 ng/m(3) for smokers' households. Median concentrations of Ce were 0.4 ng/m(3) and 9.6 ng/m(3), and median concentrations of La were 0.2 ng/m(3) and 5.9 ng/m(3) for non-smokers' and for smokers' households, respectively. In the different types of hospitality venues median levels ranged from 2.6 to 9.7 ng/m(3) for Cd, from 18.5 to 50.0 ng/m(3) for Ce and from 10.6 to 23.0 ng/m(3) for La with highest median levels in discotheques.

CONCLUSIONS

The high concentrations of Ce and La found in ETS enriched indoor air of smokers' households and hospitality venues are an important finding as Ce and La are associated with adverse health effects and data on this issue are scarce. Further research on their toxicological, human and public health consequences is urgently required.

Phthalates and their metabolites in breast milk--results from the Bavarian Monitoring of Breast Milk (BAMBI)

Phthalates have long been used as plasticizers to soften plastic products and, thus, are ubiquitous in modern life. As part of the Bavarian Monitoring of Breast Milk (BAMBI), we aimed to characterize the exposure of infants to phthalates in Germany. Overall, 15 phthalates, including di-2-ethylhexyl phthalate (DEHP), di-n-butyl phthalate (DnBP), di-isobutyl phthalate (DiBP), di-isononyl phthalate (DiNP), three primary metabolites of DEHP [mono-(2-ethylhexyl) phthalate (MEHP), mono-isobutyl phthalate (MiBP), and mono-n-butyl phthalate (MnBP)], and two secondary metabolites of DEHP were analyzed in 78 breast milk samples. We found median concentrations of 3.9 ng/g for DEHP, 0.8 ng/g for DnBP, and 1.2 ng/g for DiBP, while other parent phthalates were found in only some or none of the samples at levels above the limit of quantitation. In infant formula (n=4) we observed mean values of 19.7 ng/g (DEHP), 3.8 ng/g (DnBP), and 3.6 ng/g (DiBP). For MEHP, MiBP, and MnBP, the median values in breast milk were 2.3 μg/l, 11.8 μg/l, and 2.1 μg/l, respectively. The secondary metabolites were not detected in any samples. Using median and 95th percentile values, we estimated an "average" and "high" daily intake for an exclusively breast-fed infant of 0.6 μg/kg body weight (b.w.) and 2.1 μg/kg b.w., respectively, for DEHP, 0.1 μg/kg b.w. and 0.5 μg/kg b.w. for DnBP, and 0.2 μg/kg b.w. and 0.7 μg/kg b.w. for DiBP. For DiNP, intake values were 3.2 μg/kg b.w. and 6.4 μg/kg b.w., respectively, if all values in milk were set half of the detection limit or the detection limit. The above-mentioned "average" and "high" intake values corresponded to only about 2% to 7%, respectively, of the recommended tolerable daily intake. Thus, it is not likely that an infant's exposure to phthalates from breast milk poses any significant health risk. Nevertheless, other sources of phthalates in this vulnerable phase have to be considered. Moreover, it should be noted that for infants nourished with formula, phthalate intake is of the same magnitude or slightly higher (DEHP) than for exclusively breast-fed infants.

Effects of chain length, chlorination degree, and structure on the octanol-water partition coefficients of polychlorinated n-alkanes

Log octanol-water partition coefficients (log Kow) of 40 synthesized polychlorinated n-alkanes (PCAs) with different chlorination degrees were determined using reversed-phase high performance liquid chromatography (RP-HPLC). In addition, log Kow values of a technical mixture namely Cereclor 63L as well as 15 individual in house synthesized C10, C11, and C12 chloroalkanes with known chlorine positions were estimated. Based on these results, the effects of chain length, chlorination degree, and structure were explored. The estimated log Kow values ranged from 4.10 (polychlorinated n-decanes with 50.2% chlorine content) to 11.34 (polychlorinated n-octacosanes with 54.8% chlorine content) for PCAs and from 3.82 (1,2,5,6,9,10-hexachlorodecane) to 7.75 (1,1,1,3,9,11,11,11-octachlorododecane) for the individual chloroalkanes studied. The results showed that log Kow value was influenced linearly at a given chlorine content by chain length, while a polynominal effect was observed in dependence on the chlorination degree of an alkane chain. Chlorine substitution pattern influenced markedly the log Kow value of chloroalkanes.

Determination of free and total bisphenol A in urine of infants

Infants may be particularly sensitive regarding hormonally active compounds such as Bisphenol A (BPA), which is widely distributed and exhibits weak oestrogenic activity. Since only free (unconjugated) BPA exhibits endocrine activity, both free and total (after hydrolysis of conjugates) BPA were determined in urine samples of infants to support valid risk assessments. Free BPA was observed above the LOQ in only 3 of 91 (3%) samples from 47 infants. As total BPA was observed in only 38 (42%) urine samples, with concentrations between <LOQ and 17.85 μg/l, the median concentration was below the LOQ of 0.45 μg/l. Based on 0.225 μg/l (half of the LOQ), a margin of exposure 1400-fold below the tolerable daily intake (TDI) of 50 μg/kg bw was calculated. The highest concentration observed (17.85 μg/l) was 18-fold below the TDI. Infants who were fed using baby bottles show approximately 2-fold higher median levels of total BPA. Importantly, the higher levels of total BPA compared to free BPA demonstrate that conversion of BPA to biologically inactive conjugates such as glucuronides or sulphates, which is well known to efficiently occur in adults, also occurs in infants.

[Breast-feeding training programme as intervention approach at the hospital level: results of evaluation of the first phase of the STELLA study]

BACKGROUND

The health-promoting short- and long-term effects of breast-feeding are supported by a vast scientific literature. The Bavarian prospective cohort study 2005/2006 showed regional variations of breast-feeding rates. Furthermore, improvement in counselling mothers, particularly with regard to prevention and handling of breast-feeding problems, has a great potential for health promotion. The objective of this study is to promote breast-feeding in maternity clinics by improving the surrounding conditions.

STUDY DESIGN

A clinic-based and community-related intervention trial was carried out in Lower Bavaria as a model region with below average breast-feeding rates. (1) INTERVENTION: an advanced training of maternity ward professionals of 10 hospitals and after-care midwives was performed from May until December 2008. The training programme was based on the WHO/UNICEF criteria of the "Ten Steps to Successful Breastfeeding" to deepen the breast-feeding knowledge and to improve the breast-feeding management. (2) EVALUATION: A singular assessment of the advanced training programme was undertaken concerning an increase of knowledge and the practicability in clinical everyday life by participants; improvements of the maternity wards were assessed via structural interviews with maternity ward staff before and after intervention.

RESULTS

Approximately 85% (n=378) of the staff of the 10 maternity clinics attended the training course. The survey after the training programme (response rate 83%) indicated that more than 80% of the participants stated to have learned something new and to be able to use the knowledge acquired for their own practice. Results of the clinic interviews showed a transfer of training contents into clinical work routines. Improvements at interview date were shown best for bonding (all 10 maternity clinics), for additional feeding (8 maternity clinics) as well as for 24-h rooming-in and mother counselling (7 maternal clinics each).

CONCLUSION

Training of maternity ward professionals accounts for baby-friendly conditions in maternity clinics. Most willingness for improvements was shown by maternity ward staff particularly for bonding between mother and child as well as for additional feeding. Considerable differences between the hospitals were observed for the promotion of infant formulas before and after the intervention.

Pre- and postnatal exposure to perfluorinated compounds (PFCs)

Perfluorinated compounds (PFCs) are a group of chemicals widely used for many applications. In this study PFCs were investigated in maternal blood during pregnancy (at two time points) (n = 40 and 38) and 6 months after delivery (n = 47), in cord blood (n = 33) and in blood of infants six (n = 40) and nineteen months (n = 24) after birth, and monthly in breast milk samples in Germany. Concentrations in maternal serum ranged from 0.5 to 9.4 μg/L for perfluorooctane sulfonate (PFOS) and 0.7 to 8.7 μg/L for perfluorooctanoic acid (PFOA). In cord serum, the values ranged from 0.3 to 2.8 μg/L and from 0.5 to 4.2 μg/L for PFOS and PFOA, respectively. The median results from serum at six and nineteen months of age were 3.0 and 1.9 μg/L for PFOS and 6.9 and 4.6 μg/L for PFOA, respectively. In breast milk samples, PFOS ranged from <0.03 to 0.11 μg/L (median: 0.04 μg/L), while PFOA was detected only in some samples as were all other PFCs. Overall, we found low levels of PFCs in cord sera and an increase in concentrations through the first months of infant life. Although the concentrations in breast milk were low, this intake led to a body burden at the age of six months similar to (PFOS) or higher than (PFOA) that found in adults.

Low serum levels of perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) in children and adults from Afghanistan

Applications of perfluorinated compounds (PFCs) have led to a PFC exposure of the general population worldwide. Most PFC human biomonitoring data are available from developed countries. Here we report for the first time PFC levels in serum from children and adults living in the low developed country of Afghanistan. Among a health cooperation project we had the chance to collect blood samples from 12 children (age 2.5-9 years) and 43 adults (age 20-65 years). 25 participants were from Kabul and 30 lived in a rural area. Drinking water samples were collected from 10 tap water and 16 well water sources. PFC levels were determined by HPLC and MS/MS detection after offline protein precipitation with acetonitrile. PFOS could be quantified in all blood samples (limit of quantification, LOQ: 0.1 microg/l). Median (range) was 1.2 microg/l (0.21-11.8 microg/l). Most PFOA (n=43) and PFHxS levels (n=42) were below LOQ of 0.5 microg/l. Maximum levels were 1.5 (PFOA) and 3.0 microg/l (PFHxS). All PFOS and PFOA concentrations in drinking water were below LOQ (PFOA 0.03 microg/l and PFOS 0.015 microg/l). It is concluded that exposure to PFCs also occurs in Afghanistan but on a very low level.

Exposure to secondhand tobacco smoke and child behaviour - results from a cross-sectional study among preschool children in Bavaria

AIM

To evaluate the association of postnatal exposure to secondhand tobacco smoke on childhood behavioural problems after taking maternal smoking during pregnancy into account.

METHODS

In a cross-sectional survey of preschool children in Bavaria, exposure to secondhand tobacco smoke in the child's home was assessed via a parent questionnaire. The Strength and Difficulties Questionnaire (SDQ) was applied to assess child's behaviour. The association with secondhand tobacco smoke exposure was assessed for 'probable' outcomes of the problem subscales and of prosocial behaviour.

RESULTS

Among 5494 children (48% female), the SDQ indicated behavioural problems in up to 11%. After adjustment for socioeconomic factors, low birth weight and maternal smoking before and during pregnancy, a dose-response relationship with exposure to secondhand tobacco smoke was observed regarding hyperactivity/inattention (odds ratio compared to 'none' was 1.35 for 'low/medium' and 2.39 for 'high' exposure, 95% confidence intervals 1.02-1.78 and 1.62-3.53, respectively) as well as for conduct problems (OR 1.68 (1.37-2.06) and 1.93 (1.39-2.68)).

CONCLUSION

Secondhand tobacco smoke exposure at home appears to be associated with an increased risk of behavioural problems among preschool children. Prevention of behavioural problems may be a further reason to target secondhand tobacco smoke exposure in children.

Human exposure to polybrominated diphenyl ethers (PBDE), as evidenced by data from a duplicate diet study, indoor air, house dust, and biomonitoring in Germany

Polybrominated diphenyl ethers (PBDE) are used as flame retardants in a wide variety of products. As part of the Integrated Exposure Assessment Survey (INES), this study aimed to characterize the exposure of an adult German population using duplicate diet samples, which were collected daily over seven consecutive days, and indoor air and house dust measurements. Our study population consisted of 27 female and 23 male healthy subjects, aged 14-60 years, all of whom resided in 34 homes in southern Bavaria. In these 34 residences the air was sampled using glass fiber filters and polyurethane foams and the dust was collected from used vacuum cleaner bags. The median (95th percentile) daily dietary intake of six Tetra- to HeptaBDE congeners was 1.2 ng/kg b.w. (3.3 ng/kg b.w.) or 67.8 ng/day (208 ng/day) (calculated from the 7-day median values of each study subject). Concentrations in indoor air and dust (cumulative Tri- to DecaBDE congener readings) ranged from 8.2 to 477 pg/m(3) (median: 37.8 pg/m(3)) and 36.6 to 1580 ng/g (median: 386 ng/g), respectively. For some congeners, we identified a significant correlation between air and dust levels. The median (95th percentile) blood concentration of total Tetra- to HexaBDE congener readings was 5.6 (13.2)ng/g lipid. No significant sex differences were observed, but higher blood concentrations were found in younger participants. Using a simplified toxicokinetic model to predict the body burden from exposure doses led to results that were of the same order of magnitude as the measured blood concentrations. Based on these measurements and given our exposure assumptions, we estimated for the total tetra- to heptabrominated congener count an average (high) comprehensive total daily intake of 1.2 ng/kg b.w. (2.5 ng/kg b.w.). Overall, our results suggest that dietary exposure is the dominant intake pathway at least in our study population, responsible for 97% (average intake) and 95% (high intake) of the total intake of an adult population.

Intake and body burden of dioxin-like compounds in Germany: the INES study

The human body burden of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) and the dietary intake of dl-PCB were investigated in Germany. In total, 50 adults (between 14 and 60 years old) were recruited, and duplicate diet samples were collected over seven consecutive days from each participant. Blood samples were acquired from 48 participants. Seventeen PCDD/Fs and 12 dl-PCBs (non- and mono-ortho congeners) were measured in the blood, and all dl-PCBs were measured in duplicate diet portions. Daily intake via food was calculated by multiplying the measured concentrations by the consumption data. Median (95th percentile) concentrations in the blood (expressed as WHO-TEQ) for PCDD/Fs, non-ortho PCBs and mono-ortho PCBs were 10.1 (25.0) pg g(-1) lipid, 4.2 (14.9) pg g(-1) lipid and 4.5 (14.2) pg g(-1) lipid, respectively. The contribution of mono-ortho PCBs and non-ortho PCBs to total TEQ was 25% and 24%, respectively. For each study subject, median intake levels for seven consecutive days were calculated. From these data, the median (95th percentile) daily intake via food was 0.12 (0.32) pg TEQ kg(-1)b.w. for non-ortho congeners and 0.06 (0.12) pg TEQ kg(-1)b.w. for the mono-ortho congeners. PCB 126, PCB 118 and PCB 156 accounted for about 93% of the total PCB intake. Our study indicates that dl-PCB exposure in adults consuming a normal mixed diet is quite low at present in Germany. The median and maximum daily intake contributed to 10% and 25% to the tolerable daily intake recommended for total PCDD/Fs and dl-PCBs.