1-Hydroxypyrene and 3-hydroxybenzo[a]pyrene as biomarkers of exposure to PAH in various environmental exposure situations

Objective

To evaluate the utility of urinary 3-hydroxybenzo[a]pyrene (3-OH-B[a]P) as a biomarker of exposure to polycyclic aromatic hydrocarbons (PAHs) in various environmental exposure scenarios alongside the more usually studied 1-hydroxypyrene (1-OH-Pyr).

Methods

Two groups of 15 and 10 non smoking, healthy men and women, were exposed for approximately 6 h to ambient air at two outdoor locations close to metallurgical industries, and at one indoor location in an urban setting. Atmospheric measurements of 16 “priority” PAHs were carried out during each exposure. Urinary 1-OH-Pyr and 3-OH-B[a]P were also analysed, samples being taken the morning before exposure, at the end of exposure, then 4 and 15 h after the end of exposure. Urinary 1-OH-Pyr and 3-OH-B[a]P were analysed using high performance liquid chromatograph with fluorescence detection. Limits of detection (LOD) were 0.092 nmol/L and 0.28 pmol/L for 1-OH-Pyr and 3-OH-B[a]P respectively.

Results

Average ambient air concentrations varied from 0.27 to 2.87 ng/m³ for pyrene, 0.04 to 1.20 ng/m³ for B[a]P, and from 70.0 to 910.6 ng/m³ for the sum of the 16 PAH (ΣPAHs). Concentrations of 1-OH-Pyr were not correlated with atmospheric concentrations of PAHs to which subjects were exposed, nor with the concentrations of 3-OH-B[a]P. Nearly 80% of measurements of 3-OH-B[a]P were lower than the LOD and no relationship between atmospheric concentrations and urinary metabolites was observable. However, the percentage of post-exposure values of 3-OH-B[a]P greater than the LOD increased significantly with the median of atmospheric concentrations of Pyr, B[a]P and ΣPAH at the different sites (test of linear trend, p < 0.02 in all cases).

Conclusion

Although we used very sensitive techniques for the measurements of urinary metabolites, especially for 3-OH-B[a]P, neither 1-OH-Pyr nor 3-OH-B[a]P were an unequivocal biomarker of exposure to atmospheric PAHs in environmental exposure scenarios relevant to the general population. It would be interesting to investigate other urinary monohydroxy PAH metabolites in this context.     

Exposure to polycyclic aromatic hydrocarbons and missed abortion in early pregnancy in a Chinese population

Background

Polycyclic aromatic hydrocarbons (PAHs) are formed during incomplete burning of fossil fuels, wood, and tobacco products. High PAH exposure has been associated with low birth weight, intrauterine growth restriction, and preterm birth, but little is known about its impact on adverse outcomes in early pregnancy such as in-utero fetal death.

Objectives

To examine associations between exposure to PAHs and missed abortion in which the embryo has died but a miscarriage has not yet occurred during early pregnancy in a Chinese population in Tianjin.

Methods

A case-control study was conducted from April to November, 2007 in Tianjin, China. Cases experienced a missed abortion while controls underwent elective abortions before 14 weeks of pregnancy. Eighty-one cases were recruited from four hospitals, with the same number of controls matched on hospital, maternal age (± 8 years), gravidity (1 or >1), and gestational age (± 30 days). Two maternal measures of PAH exposures were obtained based on benzo[a]pyrene (BaP) DNA adducts in 1) aborted tissues and 2) maternal blood (for a subset of subjects). In addition, proxy measures for PAH exposures from different sources were derived from maternal interviews.

Results

In conditional logistic regression analyses, we estimated more than 4-fold increase in risk of having experienced a missed abortion in women with above the median levels of blood BaP-DNA adducts (adjusted OR = 4.27; 95% CI, 1.41-12.99); but no increase with adduct levels in aborted tissues (adjusted OR = 0.76; 95% CI, 0.37-1.54). BaP-DNA adduct levels in maternal blood and aborted tissues were poorly correlated (r = − 0.12; n = 102). Missed abortion risk also was higher among women reporting traffic congestion near the residence, commuting by walking, and performing regular cooking activities during pregnancy.

Conclusion

High levels of maternal PAH exposures may contribute to an increased risk of experiencing a missed abortion during early pregnancy.     

Outdoor, but not indoor, nitrogen dioxide exposure is associated with persistent cough during the first year of life

Background and aims

Because their lungs and immune system are not completely developed, children are more susceptible to respiratory disease and more vulnerable to ambient pollution. We assessed the relation between prenatal and postnatal nitrogen dioxide (NO₂) levels and the development of lower respiratory tract infections (LRTI), wheezing and persistent cough during the first year of life.

Methods

The study population consisted of 352 children from a birth cohort in Valencia, Spain. Prenatal exposure to NO₂, a marker of traffic related air pollution was measured at 93 sampling sites spread over the study area during four different sampling periods of 7 days each. It was modeled for each residential address through land use regression using the empirical measurements and data from geographic information systems. Postnatal exposure was measured once inside and outside each home using passive samplers for a period of 14 days. Outcomes studied were any episode of LRTI during the child's first year of life diagnosed by a doctor (bronchitis, bronchiolitis or pneumonia), wheezing (defined as whistling sounds coming from the chest), and persistent cough (more than three consecutive weeks). Outcomes and potential confounders were obtained from structured questionnaires. Multiple logistic regression was used to identify associations.

Results

The cumulative incidence (CI) at first year of life was 30.4% for LRTI (23.0% bronchiolitis, 11.9% bronchitis and 1.4% pneumonia), 26.1% for wheezing and 6.3% for persistent cough. The adjusted odds ratio (95% confidence interval) per 10 μg/m³ increment in postnatal outdoor NO₂ concentration was 1.40 (1.02-1.92) for persistent cough. We also found some pattern of association with LRTI, bronchiolitis, bronchitis, wheezing and persistent cough in different prenatal periods, although it was not statistically significant.

Conclusions

Our results indicate that exposure to outdoor, but not indoor, NO₂ during the first year of life increases the risk of persistent cough.     

Total blood mercury, plasma homocysteine, methylmalonic acid and folate in US children aged 3-5 years, NHANES 1999-2004

Background

Mercury is a known neurotoxicant; however, the relationship between childhood exposures and neurodevelopmental outcomes is uncertain, and may be modified by nutrition-related susceptibilities. In vitro studies found that mercury inhibited methionine synthase, an enzyme that interacts with vitamin B-12 and folate to regenerate the amino acid methionine from homocysteine, and inhibition of methionine synthase diverted homocysteine to cysteine and glutathione synthesis. The relationships between mercury, homocysteine, B-12, and folate have not been examined in children.

Objective

This study aimed to evaluate associations between Hg and homocysteine in male and female children differentiated by higher and lower methylmalonic acid (MMA, an indicator of vitamin B-12 deficiency) and folate status.

Design

Cross-sectional data on total blood mercury (Hg), plasma homocysteine, MMA, and serum folate were obtained from the 1999-2004 National Health and Nutrition Examination Surveys for children aged 3-5 years (n = 1005). We used multiple linear regression to evaluate relationships between homocysteine and Hg quartiles, stratified by sex, MMA ≥ and folate < sample medians, adjusted for demographic, anthropometric, and environmental factors.

Results

In boys with higher MMA and lower folate (n = 135), but not in other children, we observed inverse associations between homocysteine and Hg. Children with Hg > 3.49 μmol/L showed 1.14 μmol/L lower homocysteine (p < 0.001) relative to the lowest quartile (≤ 0.70 μmol/L) {p-value for trend < 0.001}. Compared to other subsamples, this subsample had significantly higher homocysteine levels.

Conclusion

Hg was inversely correlated with plasma homocysteine in young boys, but not girls, with higher MMA and lower folate. Additional studies are merited to evaluate Hg and amino acid metabolism in susceptible children.     

Lead exposure is associated with a delay in the onset of puberty in South African adolescent females: Findings from the Birth to Twenty cohort

Introduction

One of the suggested, yet under-researched, causes of pubertal delay is lead exposure. In South Africa blood lead levels are generally higher than in resource-rich countries. Thus the effects of lead exposure on pubertal development may be significant.

Objective

The objective of this study is to determine the association between lead exposure and pubertal development in adolescent females in the Birth to Twenty cohort (Bt20).

Methods

Bt20 is a Johannesburg based birth cohort study that commenced in 1990 and includes 1682 girls. At 13 years of age venous blood samples were collected from 725 adolescent female participants for lead content analyses; of these, 712 had menarche data. Pubertal measurement was based on age of menarche and self-reported Tanner staging for pubic hair (n = 684) and breast development (n = 682).

Results

The mean blood lead level for the sample was 4.9 μg/dl. Fifty percent had blood lead levels < 5.0 μg/dl, 49% were ≥ 5.0 μg/dl and 1% was > 10.0 μg/dl. The average age of menarche was 12.7 years. At 13 years, 4% and 7% had reached Tanner stage 5 for pubic hair and breast development, respectively. Analyses showed that higher blood lead levels were associated with significant delays in the onset of puberty (p < 0.001).

Conclusion

The study found that higher blood lead levels were associated with a delay in the onset of puberty, after adjustment for confounders. Lead exposure in resource-poor countries is generally higher compared to resource-rich countries and thus the effects of high blood levels have personal and public health significance.     

Lead in saliva from lead-exposed and unexposed children

Introduction

Whole blood is used for diagnosis of lead exposure. A non-invasive method to obtain samples for the biomonitoring of lead contamination has become a necessity. This study 1) compares the lead content in whole saliva samples (Pb-saliva) of children from a city with no reported lead contamination (Ribeirão Preto, São Paulo State, Brazil) and children of a region notoriously contaminated with lead (Bauru, São Paulo State, Brazil), and 2) correlates Pb-saliva with the lead content in the enamel microbiopsy samples (Pb-enamel) in the case of these two populations.

Methods

From a population of our previous study that had included 247 children (4- to 6-year-old) from Ribeirão Preto, and 26 children from Bauru, Pb-saliva was analyzed in 125 children from Ribeirão Preto and 19 children from Bauru by inductively coupled plasma mass spectrometry (ICPMS). To correlate Pb-saliva with Pb-enamel, we used Pb-enamel data obtained in our previous study. The Mann-Whitney test was employed to compare the Pb-saliva data of the two cities. Pb-saliva and Pb-enamel values were then Log₁₀ transformed to normalize data, and Pb-saliva and Pb-enamel were correlated using Pearson's correlation coefficient.

Results

Median Pb-saliva from the Ribeirão Preto population (1.64 μg/L) and the Bauru population (5.85 μg/L) were statistically different (p < 0.0001). Pearson's correlation coefficient for Log₁₀ Pb-saliva versus Log₁₀ Pb-enamel was 0.15 (p = 0.08) for Ribeirão Preto and 0.38 (p = 0.11) for Bauru.

Conclusions

A clear relationship between Pb-saliva and environmental contamination by lead is shown. Further studies on Pb-saliva should be undertaken to elucidate the usefulness of saliva as a biomarker of lead exposure, particularly in children.     

Prenatal exposure to organochlorine pesticides and TSH status in newborns from Southern Spain

Objective

To investigate the association between prenatal exposure to organochlorine pesticides (OCPs) and thyroid-stimulating hormone (TSH) levels in male newborns.

Methods

Exposure to 17 OCPs was analyzed in 220 placentas from a male birth cohort in Southern Spain, and TSH was measured in the umbilical cord blood. OCP concentrations were quantified by gas chromatography and mass spectrometry. Multivariate regression analysis was conducted to examine the association between pesticide exposure and neonatal TSH levels, adjusting for confounders.

Results

Newborn boys with higher exposure to endrin in placenta had higher odds of TSH cord blood levels ≥ 5 mU/L (80th percentile) (OR = 2.05; 95% CI = 1.01, 4.18; p = 0.05), whereas higher prenatal exposure to endosulfan-sulfate was associated with lower odds of TSH ≥ 5 mU/L (OR = 0.36; 95% CI = 0.17, 0.77; p = 0.008). A marginally significant negative association was found between TSH and hexachlorobenzene levels (β = − 0.15; 95% CI = − 0.31, 0.02; p = 0.09), and exposure to p,p′-DDE showed a marginally-significant higher odds of TSH ≥ 5 mU/L (OR = 1.32; 95% CI = 0.95, 1.83; p = 0.09). No association was found between TSH and the remaining pesticides.

Conclusions

Early exposure to certain environmental chemicals with endocrine-disruption activity may interfere with neonatal thyroid hormone status; however, the pattern of interference is not yet clearly elucidated.     

Respiratory effects of indoor particles in young children are size dependent

Background

Extensive epidemiological studies have provided evidence of an association between elevated outdoor particulate air pollution and adverse health effects. However, while people typically spend majority of time indoors, there is limited knowledge on airborne indoor particles and on the correlation between the concentrations of indoor particles and health effects. Even insights into the influence of differently sized indoor particles on human health are still rare.

Objective

The association between differentially sized indoor air particles and the development of respiratory diseases was studied for three year aged children.

Methods

Short-term measurements of particle mass and number concentrations were carried out in children's rooms. Information on possible particle sources (smoking habits, type of heating, and traffic) and respiratory outcomes were obtained from questionnaires. Measured indoor particle concentrations were correlated with possible sources of indoor particles and with respiratory health impacts.

Results

Daily smoking, smoking more than 5 cigarettes per day at home and traffic density in front of the window of children's room were found to be related to indoor exposure by particles of different diameters. High indoor particle exposures were associated with an increased risk for the development of obstructive bronchitis and in some extent of non-obstructive bronchitis. The strongest impact was observed for the mass concentration of particles < 1 μm and the number concentration of particles > 0.5 μm. The risk increases still remain significant if tested for stability changing the number of adjustment variables or omitting randomly selected cases, respectively.

Conclusion

Our results show significant associations between indoor particle concentrations and the risks for respiratory diseases in young children. The applied short-term measurements can help to assess the health risks of indoor particles with different sizes within epidemiological studies.     

Blood lead level and its relationship to certain essential elements in the children aged 0 to 14 years from Beijing, China

Objective

To investigate blood lead level and its relationship to copper, zinc, calcium, magnesium and iron in the children aged 0 to 14 years old from Beijing, China.

Methods

We classified 3181 children into one of the four groups: Group A (n = 783, < 1 year old); Group B (n = 1538, 1-3 years old); Group C (n = 443, 3-7 years old); and, Group D (n = 417, 7-14 years old). All these metal elements were determined by atomic absorption spectrometry.

Results

The blood lead level was 0.207 ± 0.105 μmol/L. There was a significant gender difference for zinc (P < 0.05) in Group C, and there was also a significant gender difference for copper (P < 0.05) and lead (P < 0.05) in Group D. Controlling for gender and age, we observed that there was a negative correlation of lead with zinc (r = − 0.052, P < 0.01), magnesium (r = − 0.042, P < 0.05) and iron (r = − 0.031, P < 0.05), respectively. Furthermore, in the children aged 1-7 years old, we also found there was a negative linear correlation of lead with zinc, magnesium and iron, respectively (P < 0.01).

Conclusion

Blood lead level in children from Beijing was markedly decreased. And deficiency of zinc, magnesium and iron is related to the elevated blood lead level in the children aged 1-7 years.     

Heavy metal exposure in patients suffering from electromagnetic hypersensitivity

Background

Risks from electromagnetic devices are of considerable concern. Electrohypersensitive (EHS) persons attribute a variety of rather unspecific symptoms to the exposure to electromagnetic fields. The pathophysiology of EHS is unknown and therapy remains a challenge.

Objectives

Heavy metal load has been discussed as a potential factor in the symptomatology of EHS patients. The main objective of the study was to test the hypothesis of a link between EHS and heavy metal exposure.

Methods

We measured lead, mercury and cadmium concentrations in the blood of 132 patients (n = 42 males and n = 90 females) and 101 controls (n = 34 males and n = 67 females).

Results

Our results show that heavy metal load is of no concern in most cases of EHS but might play a role in exceptional cases.

Conclusions

The data do not support the general advice to heavy metal detoxification in EHS.     

Whole blood mercury and selenium concentrations in a selected Austrian population: does gender matter?

Background

Data on mercury exposure of the Austrian population were inadequate. This study was performed to determine the causal factors underlying mercury exposure and selenium concentrations, and to estimate the gender-related health impacts.

Methodology

Venous blood samples of 78 women and 81 men were drawn at the Austrian Red Cross, Vienna. Mercury contents in acid-digested whole blood samples were measured after amalgam enrichment by CV-AAS, and selenium by AAS (heated quartz-cell) after hydrid formation.

Results

The average total mercury blood content of Austrians was low (2.38 ± 1.55 μgL^− 1; N = 152). Mercury and selenium concentrations were not different between the genders (P > 0.05) but we observed discrepancies regarding the causal factors. Mercury levels in men were influenced not only by fish consumption but also by age, education level, and amalgam fillings, whereas in women, only the diet (fish/seafood, red wine consumption) determined blood mercury (P < 0.05). Moreover, only the males indicated a depressive effect of dental amalgam on hematocrit (P < 0.05). Regarding selenium, age and alcohol consumption led to lower concentrations in men, whereas a high-level education had the opposite effect; no determinant was found for women. For the whole study group, a significant effect of chronic disease on selenium levels could be detected (P < 0.05). 18% of women and 13% of men showed marginal selenium deficiency (blood selenium < 65 μgL^− 1). Selenium and mercury concentrations were not correlated.

Conclusions

Our results indicate the need to evaluate and integrate gender-related findings in metal toxicology and trace element research, because different causal factors require different preventive measures to reduce mercury exposure and the risk of low selenium concentrations. Future research is needed on the gender- and age-related differences in fish/seafood consumption habits, the modifications of mercury toxicokinetics through sex hormones, the selenium supply in Austria, and the clinical relevance of a low selenium status.     

Sub-micrometer particulate air pollution and cardiovascular mortality in Beijing, China

Background

While the link between particulate matter and cardiovascular mortality is well established, it is not fully investigated and understood which properties of the aerosol might be responsible for the health effects, especially in polluted mega-city areas.

Objectives

Our goal was to explore the association between daily cardiovascular mortality and different particle metrics in the sub-micrometer range in Beijing, China.

Methods

We obtained daily counts of cause-specific cardiovascular deaths in the Beijing urban area for the period March 2004 to August 2005. Concurrently, continuous measurements of particle number size distributions were performed. Particle number concentrations (NC) between 0.003 μm and 0.8 μm were converted to particle mass and surface area concentrations assuming spherical particles. Semi-parametric Poisson regression models adjusting for trend, seasonality, day of the week, and meteorology were used to estimate immediate, delayed and cumulative particle effects. Additionally, effect modification by air mass origin was investigated.

Results

We observed associations between daily cardiovascular mortality and particle NC for a 2-days delay. Moreover, nearly all particle metrics showed 2-days delayed associations with ischemic heart disease mortality. The strongest association was found for particle NC in the size range 0.03-0.1 μm (7.1% increase in daily mortality with a 95%-confidence interval of 2.9%-11.5%, per an increase of 6250 particles/cm³). Results for surface and mass concentrations with a lag of two days indicated effect modification by air mass origin, whereas effects of particle NC were not modified.

Conclusions

Results show an elevated risk of cardiovascular mortality in Beijing from short-term exposure to particulate air pollution in the sub-micrometer range. Results also indicate that locally produced smaller particles and regionally transported particles may exhibit different effects in Beijing.     

Association between blood lead levels (< 5 μg/dL) and inattention-hyperactivity and neurocognitive profiles in school-aged Korean children

Objectives

The association between low blood lead levels (< 5 μg/dL) and the inattention-hyperactivity symptoms and neurocognitive profiles of school-aged Korean children was investigated.

Methods

We measured blood lead levels in 256 Korean children aged 8-10 years. Teachers completed the Attention-Deficit Hyperactivity Disorder Rating Scale (T-ARS)-IV to assess inattentive and hyperactive symptoms. Parents completed the Korean version of the Learning Disability Evaluation Scale (K-LDES). Children performed neurocognitive tests [The Continuous Performance Test (CPT), the Children's Color Trails Test, and the Stroop Color and Word Test (SCWT)].

Results

A linear regression analysis indicated that the blood lead concentrations were associated with the inattention scores [B = 4.8, S.E. = 1.6, 95% confidence interval (CI): 1.5-8.0], the hyperactivity subscores (3.1, 1.4, 0.3-5.9), and the total score (7.9, 2.9, 2.1-13.6) on the T-ARS; the number of omission errors on the CPT (20.6, 7.1, 6.5-34.6); the listening (−1.4, 0.7, −2.8 to −0.1), reading (−2.1, 0.7, −3.4 to −0.7), writing (−2.0, 0.7, −3.4 to −0.6), spelling (−2.2, 0.7, −3.7 to −0.7), and calculating (−1.8, 0.7, −3.1 to −0.4) scores on the K-LDES; and the color-word score on the SCWT (−6.7, 3.4, −13.3 to −0.1). A logistic regression analysis indicated that the probability of inattentive and hyperactive symptoms was increased with higher blood lead levels in boys with an odds ratio of 2.768 [B = 1.018, S.E. = 0.487, p = 0.036, 95% CI: 1.066-7.187].

Conclusion

This study suggests that even low blood lead levels (< 5 μg/dL) are associated with inattentive and hyperactivity symptoms and learning difficulties in school-aged children.     

Maternal exposure to floricultural work during pregnancy, PON1 Q192R polymorphisms and the risk of low birth weight

Background

Although there is evidence from animal studies of impaired reproductive function by exposure to organophosphates (OP), the effects on birth weight have not been sufficiently evaluated in epidemiological studies. Paraoxonase (PON1) detoxifies organophosphates by cleavage of active oxons. Some PON1 gene polymorphisms could reduce the enzyme activity and increase susceptibility to OP toxicity.

Objective

To assess the association between maternal exposure to floriculture during pregnancy and the risk of low birth weight (< 2500 g) in their offspring, as well as to evaluate the interaction between this exposure and maternal genotype for PON1 Q192R polymorphisms.

Materials and methods

A cross sectional study was carried out in two Mexican states (States of Mexico and Morelos) with high frequencies of greenhouse activity. We interviewed and collected blood samples from 264 females (floriculturists or partners of floricultural workers) who became pregnant during the 10 years prior to the interview. The questionnaire measured socioeconomic characteristics, tobacco and alcohol consumption, diseases and occupational and reproductive history. We also applied a food frequency questionnaire. Information was obtained pertaining to 467 pregnancies. DNA was extracted from white cells, and PON1 genotype was determined by Restriction Fragment Length Polymorphism for Q192R polymorphisms. Results were analyzed with generalized estimating equations models.

Results

After adjusting for potential confounders, we detected a statistically significant interaction between maternal exposure to flower growing work during pregnancy and PON1 Q192R polymorphisms on risk of low birth weight. The risk of having a baby with LBW is nearly six times higher if a mother is a floriculture worker during pregnancy and has PON1 192RR genotype (OR 5.93, 95% CI 1.28, 27.5).

Conclusion

These results suggest that the interaction between maternal floriculture work during pregnancy and 192RR PON1 genotype increases the probability of having children with LBW.     

Sources of cadmium exposure among healthy premenopausal women

Background

Cadmium, a persistent and widespread environmental pollutant, has been associated with kidney function impairment and several diseases. Cigarettes are the dominant source of cadmium exposure among smokers; the primary source of cadmium in non-smokers is food. We investigated sources of cadmium exposure in a sample of healthy women.

Methods

In a cross-sectional study, 191 premenopausal women completed a health questionnaire and a food frequency questionnaire. The cadmium content of spot urine samples was measured with inductively-coupled plasma mass spectrometry and normalized to urine creatinine content. Multivariable linear regression was used to estimate the strength of association between smoking habits and, among non-smokers, usual foods consumed and urinary cadmium, adjusted for age, race, multivitamin and supplement use, education, estimated total energy intake, and parity.

Results

Geometric mean urine creatinine-normalized cadmium concentration (uCd) of women with any history of cigarette smoking was 0.43 μg/g (95% confidence interval (CI): 0.38-0.48 μg/g) and 0.30 μg/g (0.27-0.33 μg/g) among never-smokers, and increased with pack-years of smoking. Analysis of dietary data among women with no reported history of smoking suggested that regular consumption of eggs, hot cereals, organ meats, tofu, vegetable soups, leafy greens, green salad, and yams was associated with uCd. Consumption of tofu products showed the most robust association with uCd; each weekly serving of tofu was associated with a 22% (95% CI: 11-33%) increase in uCd. Thus, uCd was estimated to be 0.11 μg/g (95% CI: 0.06-0.15 μg/g) higher among women who consumed any tofu than among those who consumed none.

Conclusions

Cigarette smoking is likely the most important source of cadmium exposure among smokers. Among non-smokers, consumption of specific foods, notably tofu, is associated with increased urine cadmium concentration.     

The effect of particle size on cardiovascular disorders--the smaller the worse

Background

Previous studies observed associations between airborne particles and cardio-vascular disease. Questions, however, remain as to which size of the inhalable particles (coarse, fine, or ultrafine) exerts the most significant impact on health.

Methods

For this retrospective study, data of the total number of 23,741 emergency service calls, registered between February 2002 and January 2003 in the City of Leipzig, were analysed, identifying 5326 as being related to cardiovascular incidences. Simultaneous particle exposure was determined for the particle sizes classes < 100 nm (UFP), < 2.5 μm (PM2.5) and < 10 μm (PM10). We used a time resolution of 1 day for both parameters, emergency calls and exposure.

Results

Within the group of cardiovascular diseases, the diagnostic category of hypertensive crisis showed a significant association with particle exposure. The significant effect on hypertensive crisis was found for particles with a size of < 100 nm in diameter and starting with a lag of 2 days after exposure. No consistent influence could be observed for PM2.5 and PM10. The Odds Ratios on hypertensive crisis were significant for the particle size < 100 nm in diameter from day 2 post exposure OR = 1.06 (95%CI: 1.02-1.10, p = 0.002) up to day 7 OR = 1.05 (95%CI 1.02-1.09, p = 0.005).

Conclusion

Ultrafine particles affect cardiovascular disease adversely, particularly hypertensive crises. Their effect is significant compared with PM2.5 and PM10. It appears necessary, from a public health point of view, to consider regulating this type of particles using appropriate measurands as particle number.     

Blood total mercury and fish consumption in the Korean general population in KNHANES III, 2005

Objectives

The obejective of this study was to assess the association between the blood total mercury concentration and fish consumption in the Korean general adult population using a representative sample.

Methods

We studied the blood mercury concentration in a representative sample of 1,749 Koreans who were included in the Third Korean National Health and Nutritional Examination Survey (KNHANES III) performed in 2005, and compared it with the frequency of fish consumption collected during the nutrition survey of KNHANES III.

Results

The geometric means of the blood mercury levels in female subjects (n = 890), male subjects (n = 859), and all participants (n = 1,749) representing adult Koreans aged ≥ 20 years were 3.70 μg/L [95% confidence interval (CI), 3.46-3.94 μg/L], 4.70 μg/L (95% CI, 4.38-5.02 μg/L), and 4.15 μg/L (95% CI, 3.93-4.38 μg/L), respectively. The geometric mean of the blood mercury level was significantly higher in the high-fish-consumption group (4.38 μg/L; more than once a week) than in the low-consumption group (3.71 μg/L: less than once a week), but the intergroup difference of 18% was less than that in Western countries. Among the nine listed individual types of fish and shellfish, there was a general trend for the blood mercury level to increase with the consumption frequency of squid, clam, salted seafood, and mackerel. The proportion of Korean women aged 20-49 years having blood mercury levels of at least 5.8 μg/L was 27.7% (150/542) in our study.

Conclusions

The blood mercury level in a representative sample of the Korean adult population was found to be associated with fish consumption in both men and women. However, a high consumption of fish increased the blood mercury level by only 18%.     

Prenatal exposure to lead in Spain: cord blood levels and associated factors

Introduction and Objective

Lead is a known neurotoxic. Fetuses and infants are very vulnerable to lead exposure, since their blood-brain barrier is not completely formed. Hence, there is an importance for monitoring of blood lead levels prenatally and during early infancy. The aim of this study is to evaluate the prenatal exposure to lead and its association with maternal factors in four population based mother-child cohorts in Spain. The present research was carried out within the framework of the INMA project INfancia y Medio Ambiente (Environment and Childhood).

Methods

A total of 1462 pregnant women were recruited between 2004 and 2008. Lead was analyzed in a sample of cord blood by thermal decomposition, amalgation, and Atomic Absorption Spectrometry. Maternal sociodemographic, lifestyle and dietary factors were obtained by questionnaires during pregnancy. A multivariate logistic regression model was constructed. The dependent variable was a dichotomous lead level variable (detected vs no detected, i.e. ≥ vs < 2 μg/dL).

Results

A low percentage of cord blood samples with lead levels ≥ 2 μg/dL were found (5.9%). Geometric mean and maximum were 1.06 μg/dL and 19 μg/dL, respectively. Smoking at the beginning of pregnancy, age, social class, weight gain during pregnancy, gravidity, and place of residence were the maternal factors associated with detectable cord blood lead levels. Mother's diet does not appear to be a determining factor of lead exposure. Nevertheless, daily intake of iron and zinc may act as a protective factor against having cord blood lead levels ≥ 2 μg/dL.

Conclusion

In the different regions of Spain taking part in this study, lead levels to which newborns are exposed are low. Mobilization of lead from bones may be the main contributor to the cord blood levels.     

Changing blood lead levels and DNA damage (comet assay) among immigrant women in Taiwan

Background

International marriage has had a rapid growth in recent years in Taiwan. However, little is known about the blood lead levels and DNA damage levels among immigrant women from resource-limited countries.

Objective

This study (a) explored differences between immigrant women and native women in demographic characteristics, blood lead levels, and DNA damage levels, and (b) identified risk factors that are associated with blood lead concentrations and DNA damage levels after immigration.

Methods

We used a structured questionnaire to collect data on socio-demographic status from (a) 71 immigrant women who had resettled in 2006 in Taichung, Taiwan and (b) 83 native women who live in the same area. Each study participant provided blood samples for lead and metal measurements, complete blood count examination, and the comet assay to measure degree of DNA damage.

Results

Immigrant women had higher mean blood lead concentration (2.23 ± 1.63 vs. 1.63 ± 1.00 μg/dl; p = 0.04) and lower mean blood zinc level (6.22 ± 2.22 vs. 6.89 ± 2.44 mg/l; p = 0.07) than native women. Resettlement time was a determinant to decrease blood lead and DNA damage levels among immigrants in Taiwan. Multiple linear regression analysis confirmed a statistically significant association between blood lead level and DNA damage, while zinc had a protective effect.

Conclusions

Public health agencies should focus on primary prevention and providing screening programs for this vulnerable population. An immigrant women's cohort should been established to follow-up and improve for elevated lead exposure families.     

Exposures to PM₂.₅ components and heart rate variability in taxi drivers around the Beijing 2008 Olympic Games

Background

Carbonaceous and metallic components of particles have been shown to play a role in particles' effects on cardiac autonomic function as measured by heart rate variability (HRV). Previously we reported the association of HRV with marked changes in traffic-related particulate air pollution around the Beijing 2008 Olympic Games in a panel of taxi drivers.

Objective

We further investigated the relationship between exposures to the carbonaceous and metallic components of traffic-related particles and HRV in the same population.

Methods

Repeated measurements of in-car exposures to particulate matter ≤ 2.5 μm in aerodynamic diameter (PM_2.5), carbon monoxide and nitrogen oxides were conducted in a group of 14 taxi drivers for one work shift in four study periods around the Beijing 2008 Olympics. The quantities of organic/elemental carbons and 27 elements of the in-car PM_2.5 mass were determined laboratorially. Linear mixed-effects models were used to evaluate the impact of exposures to different PM_2.5 components on HRV while controlling for potential confounders.

Results

Taxi drivers' exposures to in-car PM_2.5 and its components showed dramatic changes across the four study periods around the Beijing 2008 Olympics. Differences in associations of in-car PM_2.5 components with HRV were found. An interquartile range (IQR: 917.9 ng/m³) increase in calcium was associated with a 5.48 millisecond [ms, 95% confidence interval (CI): 0.71, 10.24] increase in standard deviations of normal-to-normal (SDNN) intervals, while an IQR (4.1 ng/m³) increase in nickel was associated with a 1.53 ms (95% CI: 0.14, 2.92) increase in SDNN index. Additionally, a decline of 8.11 ms (95% CI: − 15.26, − 0.97) in SDNN per IQR (481.4 ng/m³) increase in iron was also found.

Conclusion

The results support associations of PM_2.5 metallic components with HRV in younger healthy individuals. Future studies are needed to clarify the interaction among different PM_2.5 components or the role of PM_2.5 mixtures.