Sudden high concentration of TSP affected by atmospheric boundary layer in Seoul metropolitan area during duststorm period

Hourly concentrations of TSP, PM(10), PM(2.5) near the surface at Seoul city were examined from March 20 to March 25, 2001 (duststorm event) in order to investigate the effect of a duststorm generated in China on the local aerosol concentration in Korea, The ratios of fine to coarse particles such as TSP to PM(10), TSP to PM(2.5) and PM(10)-PM(2.5) to PM(2.5) showed that a great amount of dust transported from the origin of the duststorm was remarkable with a maximum ratio of 9.77 between TSP and PM(2.5). Back trajectories every 6 h showed the movement of dust particles in the lower atmosphere near 500 m to 1500 m (atmospheric boundary layer), which implied transport from Baotou in inner Mongolia of northern China to the direction of Seoul city in Korea and then the back trajectories passed near the southern border of Mongolia and Baotou through Zengzhou in the midlevels (3000 m) and low levels (500 m) of China, finally reaching Seoul city. So, the TSP concentration at Seoul city was partially influenced by the duststorm, under the prevailing westerly wind and the transported aerosols could influence high concentrations of pollutants of TSP, PM(10) and PM(2.5) in Seoul. The sudden high concentrations of TSP and PM(10) were found for a few hours, especially at 1500 to 1800 LST, March 22. At 1200 LST, before the passage of a cold front through the Korean peninsula, the convective boundary layer (CBL) near Seoul was not shallow, but at 1500 LST, under the frontal passage, the CBL was remarkably thinner (less than 300 m), due to the compression of the boundary layer by the intrusion of cold air. This resulted in the increase of the TSP concentration, even though the mixed layer above maintained almost the same depth. At 1800 LST shortly after the frontal passage, that is, near sunset, the nocturnal cooling of the ground caused air parcels to cool, thereby enhancing the shallower nocturnal surface inversion layer and producing the maximum concentration of TSP of 1388 microg/m(3) near Seoul city.     

Pesticide exposure and cancer among rural workers from Bariri, Sao Paulo State, Brazil

This article reports an environmental health study on risk identification. It discusses risk factors linked to rural work and pesticide contact in a restricted geographic area and shows the necessity of improving rural workers' health in the central part of Sao Paulo State. The municipality of Bariri, which is the case studied in this research, typifies this agriculturally based region. The study focuses on environmental problems engendered by modern agriculture that may have human-health repercussions such as cancer, as indicated by hard statistical association on an extended cause-effect time scale. For specific cases, the research used a database containing records of Amaral Carvalho Hospital, located in the city of Jau and a highly respected regional reference unit for over 85 years as one of the best in the Brazilian public health system for treating cancer. Statistics for age and gender were analyzed; relative risk was calculated for a group of cases registered from 2000 to 2002, as well as for a randomly selected control group from the same hospital. A map indicating the residences of cases (68) and non-cases (60) was made by geoprocessing techniques. For the period of time and the group studied, the authors concluded that the cancers of the skin and digestive system were the most prevalent. Bariri presented 24 cases representing all cancer types for each group of 10,000 citizens. The study indicated an almost two times higher probability of cancer development among rural workers, with a calculated relative risk between those exposed (agriculture workers) and the non-exposed (other occupations) of 1.6. No patterns of geographical distribution of cancer in that time period were recorded among rural workers of Bariri. However, the higher number of positive occurrences in the southwestern outskirts of the city indicated an area that must be prioritized in distributing environmental health information and conducting preventive education campaigns.     

Characteristics of PM10, PM2.5, CO2 and CO monitored in interiors and platforms of subway train in Seoul, Korea

This study was performed to investigate the concentration of PM(10) and PM(2.5) inside trains and platforms on subway lines 1, 2, 4 and 5 in Seoul, KOREA. PM(10), PM(2.5), carbon dioxide (CO(2)) and carbon monoxide (CO) were monitored using real-time monitoring instruments in the afternoons (between 13:00 and 16:00). The concentrations of PM(10) and PM(2.5) inside trains were significantly higher than those measured on platforms and in ambient air reported by the Korea Ministry of Environment (Korea MOE). This study found that PM(10) levels inside subway lines 1, 2 and 4 exceeded the Korea indoor air quality (Korea IAQ) standard of 150 microg/m(3). The average percentage that exceeded the PM(10) standard was 83.3% on line 1, 37.9% on line 2 and 63.1% on line 4, respectively. PM(2.5) concentration ranged from 77.7 microg/m(3) to 158.2 microg/m(3), which were found to be much higher than the ambient air PM(2.5) standard promulgated by United States Environmental Protection Agency (US-EPA) (24 h arithmetic mean: 65 microg/m(3)). The reason for interior PM(10) and PM(2.5) being higher than those on platforms is due to subway trains in Korea not having mechanical ventilation systems to supply fresh air inside the train. This assumption was supported by the CO(2) concentration results monitored in tube of subway that ranged from 1153 ppm to 3377 ppm. The percentage of PM(2.5) in PM(10) was 86.2% on platforms, 81.7% inside trains, 80.2% underground and 90.2% at ground track. These results indicated that fine particles (PM(2.5)) accounted for most of PM(10) and polluted subway air. GLM statistical analysis indicated that two factors related to monitoring locations (underground and ground or inside trains and on platforms) significantly influence PM(10) (p<0.001, R(2)=0.230) and PM(2.5) concentrations (p<0.001, R(2)=0.172). Correlation analysis indicated that PM(10), PM(2.5), CO(2) and CO were significantly correlated at p<0.01 although correlation coefficients were different. The highest coefficient was 0.884 for the relationship between PM(10) and PM(2.5).     

Natural radioactivity in refractory manufacturing plants and exposure of workers to ionising radiation

This paper shows the results of a survey carried out at some refractory manufacturing plants. During the first part of the survey, the concentration of natural radioactivity in raw materials and end-products, coming from four plants, was assessed. Several raw materials and, as a consequence, some end-products as well have shown activity concentrations exceeding a few hundreds of Bq kg⁻¹ of ²³⁸U and ²³²Th. In some important raw materials, such as bauxite and corundums, a remarkable radioactive disequilibrium was observed; this is probably due to the high temperature processes undergone by these materials. The second part of the survey focussed on the measurements of ambient equivalent dose rates, airborne dust concentrations and radon indoor. On the basis of results obtained, the effective dose for the standard worker was estimated. Two different types of refractory plants were investigated. Effective doses for both plants were lower than 1 mSv y⁻¹.     

Occupational exposure of phosphate mine workers: airborne radioactivity measurements and dose assessment

Under the Egyptian program for radiation safety and control, airborne radioactivity measurements and radiological dose assessment were conducted in some phosphate and uranium mines. Abu-Tartor mine is one of the biggest underground phosphate mines in Egypt. Airborne radioactivity, radon ((222)Rn) and its short-lived decay products (progenies) and thoron ((220)Rn), were measured in selected locations along the mine. The environmental gamma and workers dose equivalent rate (mSv/y) were measured inside and outside the mine using thermo-luminescence dosimeters (TLD). The results were presented and discussed. The calculated annual effective dose due to airborne radioactivity is the main source of occupational exposure and exceeding the maximum recommended level by ICRP-60 inside the mine tunnels. A number of recommendations are suggested to control the occupational exposures.     

Occupational exposure of farm workers to pesticides: biochemical parameters and evaluation of genotoxicity

To assess the effects of exposure to complex mixtures of pesticides in farm workers from two communities from Rio Grande do Sul, Brazil, we evaluated the activities of butyrylcholinesterase (BChE) and delta-aminolevulinic acid dehydratase (ALA-D) enzymes, hematological, lipid parameters, and genotoxicity using two tests to detect DNA damage, the Comet assay in peripheral blood leukocytes and the micronucleus (MN) test in oral mucosa cells. The use of personal protective equipment (PPE), age and smoke habits were considered in the analysis. There was a significant decrease in the BChE and ALA-D activities in farm workers (n=37) relative to the control group (n=20) (P< or =0.05 and P< or =0.001, respectively). The Comet assay in peripheral blood leukocytes showed that the Damage index and Damage frequency observed in the exposed group were significantly higher in relation to the controls (P< or =0.001, and P< or =0.05, respectively). No differences were detected regarding the hematological parameters, lipids profile, and MN frequencies. In addition, no significant differences were observed between younger (< or =38 years) and older subjects (>38 years), or between smokers and non-smokers within the groups, either by Comet assay or MN test. However, the use of PPE seems to be important in the prevention of contamination, as suggested by BChE levels and Comet assay results.     

Social and economic sustainability of urban systems: comparative analysis of metropolitan statistical areas in Ohio,USA

The development of a comprehensive sustainability analysis tool for evaluating regional urban systems would present researchers, planners, and policy makers with a powerful tool to study and manage systems, with the goal of encouraging optimum social and economic trends, while maintaining long-term environmental protection that leads to sustainability. This article intends to aid in this effort by presenting a versatile methodology for assessing sustainability as a function of dynamic changes in significant characteristics of urban systems. Using statistical methods, this work presents a strategy for comparatively assessing the impact of social and economic characteristics on system stability at geographic scales which are critical to policy and management. Specifically, it employs the Fisher Information index as a measure of sustainability, in order to distinguish periods of stability. As an application of the approach, six Metropolitan Statistical Areas (MSAs) in Ohio (Cincinnati, Dayton, Cleveland, Akron, Columbus, and Toledo) were evaluated for a regional sustainability assessment. Results from the multiyear analysis suggest two distinct periods in these MSAs: one characterized by 30 years of socio-economic growth (1970–1999) and another (2000–2009) denoting a change in the trajectory of each system found to be related to economic recession. Columbus was identified as the most stable and sustainable of the MSAs during the study period. In contrast, Toledo exhibited the largest changes in economic trends, as distinguished by excessive increases in the growth rate of vacant housing units, unemployed civilian labor force, and inhabitants below the poverty level (2000–2009). Since such conditions are not desirable for urban systems, they are indicative of movement towards an unsustainable future.     

Survey of residential extremely-low-frequency magnetic field exposure among children in Taiwan

This survey estimated the extremely-low-frequency magnetic field (ELF-MF) exposure in households with children under the age of 7 years in Taiwan. To select a representative sample, we used the probability proportional to size sampling technique and simple random cluster sampling technique to select study districts in each city/county of Taiwan. A total of 40 districts were selected and all households with children aged less than 7 (n=4184) were visited and solicited for in-home measurements. Four trained interviewers carried out spot-measurements in rooms of each selected household during a two-year period. A questionnaire inquiring residential characteristics and nearby power facilities was also administered to a parent or caregiver. ELF-MF measurements were performed in a total of 2214 households (53% participation rate). Controlling for participation rate, the weighted overall mean magnetic field exposure was estimated at 0.121 (standard deviation 0.185) micro-Tesla (microT) (range 0.010-3.304 microT). Mean exposures were higher than 0.3 and 0.4 microT in an estimated 7.3% (n=159) and 5.4% (n=115) of the households, respectively. There was a substantial agreement between overall mean residential exposure and exposure measured in children's bedrooms. In a multivariate logistic regression model, we noted that buildings with advanced age, buildings for both residential and commercial uses, and buildings close to power facilities were more likely a to have mean exposure above 0.4 microT. Our survey results indicate that residential ELF-MF exposure is likely to be higher for children in Taiwan than for children in Europe and North America.     

Characteristics of PM10, PM2.5, CO2 and CO monitored in interiors and platforms of subway train in Seoul, Korea

This study was performed to investigate the concentration of PM₁₀ and PM_2.5 inside trains and platforms on subway lines 1, 2, 4 and 5 in Seoul, KOREA. PM₁₀, PM_2.5, carbon dioxide (CO₂) and carbon monoxide (CO) were monitored using real-time monitoring instruments in the afternoons (between 13:00 and 16:00). The concentrations of PM₁₀ and PM_2.5 inside trains were significantly higher than those measured on platforms and in ambient air reported by the Korea Ministry of Environment (Korea MOE). This study found that PM₁₀ levels inside subway lines 1, 2 and 4 exceeded the Korea indoor air quality (Korea IAQ) standard of 150 μg/m³. The average percentage that exceeded the PM₁₀ standard was 83.3% on line 1, 37.9% on line 2 and 63.1% on line 4, respectively. PM_2.5 concentration ranged from 77.7 μg/m³ to 158.2 μg/m³, which were found to be much higher than the ambient air PM_2.5 standard promulgated by United States Environmental Protection Agency (US-EPA) (24 h arithmetic mean: 65 μg/m³). The reason for interior PM₁₀ and PM_2.5 being higher than those on platforms is due to subway trains in Korea not having mechanical ventilation systems to supply fresh air inside the train. This assumption was supported by the CO₂ concentration results monitored in tube of subway that ranged from 1153 ppm to 3377 ppm. The percentage of PM_2.5 in PM₁₀ was 86.2% on platforms, 81.7% inside trains, 80.2% underground and 90.2% at ground track. These results indicated that fine particles (PM_2.5) accounted for most of PM₁₀ and polluted subway air. GLM statistical analysis indicated that two factors related to monitoring locations (underground and ground or inside trains and on platforms) significantly influence PM₁₀ (p < 0.001, R² = 0.230) and PM_2.5 concentrations (p < 0.001, R² = 0.172). Correlation analysis indicated that PM₁₀, PM_2.5, CO₂ and CO were significantly correlated at p < 0.01 although correlation coefficients were different. The highest coefficient was 0.884 for the relationship between PM₁₀ and PM_2.5.     

Urinary biomarkers of flame retardant exposure among collegiate U.S. gymnasts

Flame retardants are widely used in polyurethane foam materials including gymnastics safety equipment such as pit cubes and landing mats. We previously reported elevated concentrations of flame retardants in the air and dust of a U.S. gymnastics training facility and elevated PentaBDE in the serum of collegiate gymnasts. Our objective in this pilot study was to compare urinary biomarkers of exposure to other flame retardants and additives of polyurethane foam including tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), triphenyl phosphate (TPHP) and 2-ethylhexyl- 2,3,4,5-tetrabromobenzoate (EH-TBB) in samples collected from 11 collegiate gymnasts before and after a gymnastics practice (n = 53 urine samples total). We identified a 50% increase in the TPHP biomarker (p = 0.03) from before to after practice, a non-significant 22% increase in the TDCIPP biomarker (p = 0.14) and no change for the EH-TBB biomarker. These preliminary results indicate that the gymnastics training environment can be a source of recreational exposure to flame retardants. Such exposures are likely widespread, as we identified flame retardants in 89% of foam samples collected from gyms across the U.S.     

Monitoring of firefighters exposure to smoke during fire experiments in Portugal

Forest fires represent a serious threat to public security in Europe due to the large burned area. Moreover, smoke pollution due to forest fire events is an important public health issue for the communities directly affected, and particularly for the personnel involved in firefighting operations. Aiming to contribute to the scientific knowledge concerning firefighters exposure to forest fires smoke, data of individual exposure to carbon monoxide, nitrogen dioxide, volatile organic compounds, and particulate matter were obtained during experimental field fires for a group of 10 firefighters equipped with portable “in continuum” measuring devices. Measured values are very high exceeding the Occupational Exposure Standard limits, in particular for peak limit thresholds. These are the first measurements and analysis of firefighter's individual exposure to toxic gases and particles in fire smoke experiments in Europe. However, they already indicate that urgent measures to avoid these levels of exposure are needed.     

Effects of prenatal exposure to perfluoroalkyl acids on prevalence ofallergic diseases among 4-year-old children

Perfluoroalkyl acids (PFAAs) are ubiquitous chemicals extremely resistant and widespread throughout the environment, frequently being detected in human blood samples. Animal studies have revealed that exposure to PFAAs results in immunotoxicity. However, the association between PFAAs, especially long-chain PFAAs, and allergies in humans is not well established. We examined whether prenatal exposure to PFAAs is associated with allergic diseases among 4-year-old children in a large-scale prospective birth cohort in Hokkaido, Japan. In total, 1558 mother–child pairs were included in this study and prenatal levels of eleven PFAAs were measured in maternal plasma samples obtained between 28 and 32 weeks of pregnancy by using ultra-performance liquid chromatography-tandem mass spectrometry. Participant demographic and characteristic information were obtained from self-administered pre- and postnatal questionnaires and medical birth records. Infant allergies were assessed using the Japanese version of the International Study of Asthma and Allergies in Childhood (ISAAC) Phase Three questionnaire, which was administered 4 years post-delivery. Symptoms included eczema, wheezing and rhinoconjunctivitis with a prevalence of 19.0%, 18.7%, and 5.4%, respectively. Associations of PFAA quartiles with allergic outcomes were examined using logistic models. Adjusted odds ratios (ORs) in the 4th quartile vs. 1st quartile (Q4 vs. Q1) for total allergic diseases (including at least one allergic outcome) significantly decreased for perfluorododecanoic acid (PFDoDa) (Q4 vs. Q1 OR: 0.621; 95% confidence interval (CI): 0.454, 0.847) and perfluorotridecanoic acid (PFTrDA) (Q4 vs. Q1 OR: 0.712; 95% CI: 0.524, 0.966) in all children. We obtained similar results when examining the association between PFAAs and eczema. The adjusted OR (Q4 vs. Q1) for wheezing in relation to higher maternal PFHxS levels was 0.728 (95% CI: 0.497, 1.06) in all children. In conclusion, prenatal exposure to long-chain PFAAs, such as PFDoDa and PFTrDA may have an immunosuppressive effect on allergic diseases in 4-year-old children.     

Phthalate exposure among pregnant women in Jerusalem, Israel: results of a pilot study

BackgroundPhthalates can disrupt endocrine function and induce reproductive and developmental toxicity in laboratory animals. Few studies have evaluated exposure to phthalates in pregnant women, despite the potential sensitivity of the developing fetus to adverse effects of phthalates.MethodsWe measured urinary concentrations of 11 phthalate metabolites in 19 pregnant women, recruited in Jerusalem, Israel in 2006, and collected questionnaire data on demographic factors and consumer habits from these women. We compared geometric mean concentrations in subgroups and used the Mann–Whitney U-test for independent samples to determine significant differences between groups.ResultsNine metabolites were detected in at least 95% of the samples: mono(2-ethyl-5-carboxypentyl) phthalate, mono(2-ethyl-5-hydroxyhexyl) phthalate, mono(2-ethyl-5-oxohexyl) phthalate, mono(3-carboxypropyl) phthalate, mono(n-butyl) phthalate, monobenzyl phthalate (MBzP), monoethyl phthalate (MEP), mono(2-ethylhexyl) phthalate and monoisobutyl phthalate. Phthalate metabolite concentrations in these pregnant women were remarkably similar to those in the general United States female population. MBzP geometric mean concentrations were higher in women living in buildings existing 40 years or more (P = 0.04). In women who used four or more personal care products (perfume, deodorant, lipstick, nail polish, or hand/face cream) in the 48 h prior to providing the urine sample, geometric mean MEP concentrations were more than 4 times higher than concentrations in women using only two or three of the aforementioned products (P = 0.07).ConclusionsPregnant women in Jerusalem are exposed to a wide range of phthalates. Building materials used in old constructions may be a source of exposure to benzylbutyl phthalate, the parent compound of MBzP. Personal care products may be sources of exposure to diethyl phthalate, the parent compound of MEP.     

Symptoms prevalence among office workers of a sealed versus a non-sealed building: Associations to indoor air quality

ObjectivesAn increasing number of complaints related to time spent in artificially ventilated buildings have been progressively reported and attributed, at least in part, to physical and chemical exposures in the office environment. The objective of this research was to investigate the association between the prevalence of work-related symptoms and the indoor air quality, comparing a sealed office building with a naturally ventilated one, considering, specially, the indoor concentration of TPM, TVOCs and the main individual VOCs.MethodsA cross-sectional study was performed to compare the prevalence of sick building syndrome (SBS) symptoms among 1736 office workers of a sealed office building and 950 of a non-sealed one, both in Rio de Janeiro's downtown. The prevalence of symptoms was obtained by a SBS standardized questionnaire. The IAQ of the buildings was evaluated through specific methods, to determine the temperature, humidity, particulate matter and volatile organic compound (VOC) concentrations.ResultsUpper airways and ophthalmic symptoms, tiredness and headache were highly prevalent in both buildings. Some symptoms were more prevalent in the sealed building: “eye dryness” 33.3% and 27.1% (p: 0.01); “runny nose” 37.3% and 31.3% (p: 0.03); “dry throat” 42% and 36% (p: 0.02); and “lethargy” 58.5% and 50.5% (p: 0.03) respectively. However, relative humidity and indoor total particulate matter (TPM) concentration as well as total volatile organic compounds (TVOCs) were paradoxically greater in the non-sealed building, in which aromatic compounds had higher concentration, especially benzene. The analysis between measured exposure levels and resulting symptoms showed no association among its prevalence and TPM, TVOCs, benzene or toluene concentration in none of the buildings.ConclusionsOther disregarded factors, like undetected VOCs, mites, molds and endotoxin concentrations, may be associated to the greater prevalence of symptoms in the sealed building.     

The effects of exposure of 60Co on the oxidant/antioxidant status among radiation victims

This retrospective study has been performed with radiation victims who were accidentally exposed to a 60Co source and its release into the environment. The aim of the study was to assess the effects of elevated radiation exposures on plasma level, on erythrocyte thio barbituric acid reactive substance (TBARS) level and on erythrocyte glutathione (GSH) levels. Patients were treated in different hospitals with different symptoms such as nausea, vomiting, dizziness, along with severe anemia in some patients. Blood samples were collected 3-5 days following the radiation accident. Increases in plasma (6.25 +/- 0.90 nmol ml(-1)) and erythrocyte TBARS levels (330.5 +/- 30.5 micromol gHb(-1)) were found in comparison to a healthy group (3.72 +/- 0.68 nmol ml(-1) and 150.7 +/- 20.5 micromol gHb(-1), respectively) at a significant level (p<0.001). Erythrocyte GSH levels (5.2 +/- 0.30 micromol gHb(-1)) were found to be decreased among the victims (healthy group: 10.2 +/- 0.7 micromol gHb(-1)) at the same significance level (p<0.001). These observations confirm a significant change induced by radiation in the oxidant/antioxidant status among the victims. It is suggested here that antioxidant supplementation therapy might be effective in preventing the harmful effects of 60Co radiation among radiation victims.     

Australian firefighters' exposure to air toxics during bushfire burns of autumn 2005 and 2006

Bushfire fighting is a hazardous occupation and control strategies are generally in place to minimize the hazards. However, little is known regarding firefighters' exposure to bushfire smoke, which is a complex mixture of toxic gases and particles. In Australia, during the prescribed burning season, firefighters are likely to be exposed on a regular basis to bushfire smoke, but whether these exposures affect health has yet to be determined. There are a number of factors that govern whether exposure to smoke will result in short-term and/or long-term health problems, including the concentrations of air pollutants within the breathing zone of the firefighter, the exposure duration, and health susceptibility of the individual, especially for pre-existing lung or heart disease. This paper presents measurements of firefighters' personal exposure to bushfire smoke, the first step within a risk management framework. It provides crucial information on the magnitude, extent and frequency of personal exposure to bushfire smoke for a range of typical scenarios. It is found that the primary air toxics of concern are carbon monoxide (CO), respirable particles and formaldehyde. Also, work activity is a major factor influencing exposure with exposure standards (both average and short-term limits) likely to be exceeded for activities such as suppression of spot fires, holding the fireline, and patrolling at the edge of a burn area in the urban-rural interface.     

Neurophysiological alterations due to diesel exhaust exposure during the neonatal life of the rat

This study was designed to assess the effects of diesel exhaust on the development of the nervous system in rats as measured by somatosensory and visual evoked potentials (SEPs and VEPs, respectively). SEPs, elicited by 1 mamp, 0.5 msec pulses delivered to the tibial nerve at the tibale, were recorded from the skull overlying the somatosensory projection area on days 28, 35, 42, and 49 postconception (pc). Analysis of the data for day 35 pc double pulse SEPs revealed significantly longer latencies for all peaks of the SEP in pups exposed to diesel exhaust. There were also differences indicating that the electrophysiological recoverability of the nervous system had been compromised in the diesel exhaust exposed group. On day 35 pc, the latencies of all VEP peaks occurring before 300 msec were greater in the exposed group. The differences, however, reached statistical significance only for the P2 peak of the response to the first of the paired stimuli. These data support the hypothesis that diesel exhaust influences the development of the nervous system.     

Tobacco smoke increases the risk of otitis media among Greenlandic Inuit children while exposure to organochlorines remain insignificant

BackgroundPrenatal exposure to environmental levels of organochlorines (OCs) has been demonstrated to have immunotoxic effects in humans. We investigated the relationship between prenatal exposure to OCs and the occurrence of otitis media (OM) among Inuit children in Greenland.MethodsWe estimated the concentration of 14 PCB congeners and 11 pesticides in maternal and cord blood samples and in breast milk in a population-based cohort of 400 mother–child pairs. At follow-up, we examined the children's ears and used their medical records to assess the OM occurrence and severity. Multivariate regression analyses were used with adjustments for passive smoking, crowding, dietary habits, parent's educational level, breast feeding and the use of child-care.ResultsThe children were 4–10 years of age at follow-up and 223 (85%) participated. We found no association between prenatal OC exposure and the development of OM. Factors associated with the child's hazard of OM during the first 4 years of life were: mother's history of OM (HR 1.70, 95% CI 1.11–2.59, p = 0.01); mother's smoking habits: current (HR 2.47, 95% CI 1.45–4.21, p < 0.01) and previous (HR 2.00, 95% CI 1.19–3.36, p < 0.01); number of smokers in the home (HR 1.17, 95% CI 1.05–1.31, p < 0.01). After adjustment mothers' smoking habits remained significant.ConclusionWe found no relationship between high levels of prenatal exposure of OCs and occurrence of OM. Passive smoking was found as the strongest environmental risk factor for the development of OM.Interventions to reduce passive smoke in children's environment are needed.     

Health effects of recreational exposure to Moreton Bay, Australia waters during a Lyngbya majuscula bloom

A survey of residents in an area subject to annual toxic cyanobacterial blooms was undertaken to examine potential health effects of cyanobacteria toxins. The survey assessed the health of marine recreational water users in Deception Bay/Bribie Island area in northern Moreton Bay, Queensland, which is exposed to blooms of the nuisance and potentially harmful cyanobacterium Lyngbya majuscula. A postal survey was mailed to 5000 residents with a response rate of 27%. High numbers of people (78%) responding to the survey reported recreational water activity in Moreton Bay. Of those having marine recreational water activity, 34% reported at least one symptom after exposure to marine waters, with skin itching the most reported (23%). Younger participants had greater water exposure and symptoms than older participants. Participants with greater exposures were more likely to have skin and eye symptoms than less exposed groups, suggesting agents in the marine environment may have contributed to these symptoms. Of those entering Moreton Bay waters 29 (2.7%) reported severe skin symptoms, 12 of whom attended a health professional. Six (0.6%) reported the classic symptoms of recreational water exposure to L. majuscula, severe skin symptoms in the inguinal region. Participants with knowledge of L. majuscula were less likely to report less skin, gastrointestinal and fever and headache symptoms. In conclusion, high numbers of participants reported symptoms after exposure to waters subject to L. majuscula blooms but only a small number appeared to be serious in nature suggesting limited exposure to toxins.