Impacto de la nueva legislación sobre tabaquismo (Ley 42/2010) en los niveles de humo ambiental de tabaco en locales de hostelería

Objective

To evaluate pollution by second-hand smoke in a sample of hospitality venues before and after the implementation of smoke-free legislation.

Methods

A cross sectional, before-after study was conducted in 2008 and 2011 after the total ban. A SidePack Aerosol monitor was used both inside and outside the hospitality venues to measure fine breathable particles (PM_2.5). A total of 43 places with pre- and post-legislation measurements were included.

Results

The median indoor pollution in hospitality venues was 204.2 μg/m³ in 2008 and 18.82 μg/m³ in 2011; the average outdoor PM_2.5 concentration was 47.04 μg/m³ in 2008 and 18.82 μg/m³ in 2011. Pollution was higher in bars and cafeterias, followed by pubs and discos. Before the law was implemented, pollution was 4.34 times higher indoors than outdoors; in 2011 the average indoor PM_2.5 concentration decreased by 90.88%.

Conclusions

Only a complete ban is able to protect workers and customers against the health risks of second-hand smoke exposure     

Secondhand smoke exposures in indoor public places in seven Asian countries

Exposure to secondhand smoke (SHS) is a major threat to public health. Asian countries having the highest smoking prevalence are seriously affected by SHS. The objective of the study was to measure SHS levels in hospitality venues in seven Asian countries and to compare the SHS exposure to the levels in Western countries. The study was carried out in four types of related hospitality venues (restaurant, café, bar/club and entertainment) in China, India, Japan, Korea, Malaysia, Pakistan and Sri Lanka. Real-time measurement of particulate matter of <2.5 μm aerodynamic diameter (PM_2.5) was made during business hour using a handheld laser operated monitor. A total of 168 venues were measured in seven countries. The average indoor PM_2.5 level was 137 μg/m³, ranging from 46 μg/m³ in Malaysia to 207 μg/m³ in India. Bar/club had the highest PM_2.5 level of 191 μg/m³ and restaurants had the lowest PM_2.5 level of 92 μg/m³. The average indoor PM_2.5 level in smoking venues was 156 μg/m³, which was 3.6 times higher than non-smoking venues (43 μg/m³). Indoor PM_2.5 levels were significantly associated with country, type of venue, smoking density and air exchange rate (p < 0.05). In the seven Asian countries, PM_2.5 levels were high due to SHS in public places. The current levels are comparable to the levels in Western countries before the adoption of smoke-free policy. Since Asian country has high prevalence of SHS in public places, there is an urgent need for comprehensive smoke-free regulation in Asian countries.     

Study of Secondhand Smoke Levels Pre and Post Implementation of the Comprehensive Smoking Ban in Mumbai

Objectives:

This research was undertaken with the aim of assessing the indoor air quality in popular hospitality venues, as also to evaluate the effectiveness of the nationwide comprehensive public smoking ban. The analysis was split into two halves – baseline study taken up prior to implementation of the said ban on 2^nd October 2008, and the follow-up study after it came into effect.

Materials and Methods:

Twenty-five venues including five restaurants, fourteen resto-bars, two hookah (smoking water-pipe) cafes and four pubs were selected using a mix of random, convenience and purposeful sampling. Particulate matter (PM_2.5) measurements at these venues were made using TSI SidePak AM510 Personal Aerosol Monitor.

Results:

The average PM_2.5 level in venues where smoking was permitted prior to implementation of ban was found to be 669.95 μg/m³ in the baseline study. Post ban, the average PM_2.5 level in same test venues reduced to 240.8 μg/m³. The hookah cafes were an exception as the average PM_2.5 levels exceeded the permissible limits before as well as post ban.

Conclusion:

The baseline study showed that the hospitality venues had hazardous levels of PM_2.5 particles arising from second-hand smoke prior to smoking ban. These decreased by a maximum of 64% after the law took effect. A substantial improvement in air quality at these venues post implementation of the smoking ban indicated the effectiveness of the law.     

Night entertainment venues comply poorly with the smoke-free law in Chile

The initial high level of compliance with the Chilean comprehensive national smoke-free law in 2013 is fading, particularly in the hospitality sector. This paper draws attention to how using a simple and low-cost surveillance inquiry may help focus on the use of scarce inspection resources to improve compliance with the law in the hospitality sector. We conducted a cross-sectional assessment of second-hand smoke exposure in night entertainment venues in Santiago, Chile, by measuring particulate matter of less than 2.5 μm (PM_2.5). Smoking where prohibited by law was observed in 36% of the venues visited. Venues where smoking was spotted at the time of the observation had a median PM_2.5 concentration 13 times higher than background concentration on the street. The study shows that a targeted approach for inspection to find pockets of venues with suboptimal compliance is feasible and affordable.     

Secondhand smoke exposure within semi-open air cafes and tobacco specific 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) concentrations among nonsmoking employees

Objectives

Secondhand smoke (SHS) is a defined occupational hazard. The association though between SHS exposure in semi-open air venues and tobacco specific carcinogen uptake is an area of debate.

Material and Methods

A cross sectional survey of 49 semi-open air cafes in Athens, Greece was performed during the summer of 2008, prior to the adoption of the national smoke free legislation. All venues had at least 1 entire wall open to allow for free air exchange. Indoor concentrations of particulate matter smaller than 2.5 microns (PM_2.5) attributable to SHS were assessed during a work shift, while 1 non-smoking employee responsible for indoor and outdoor table service from each venue provided a post work shift urine sample for analysis of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL).

Results

Post work shift NNAL concentrations were correlated with work shift PM_2.5 concentrations attributable to SHS (r = 0.376, p = 0.0076). Urinary NNAL concentrations among employees increased by 9.5%, per 10 μg/m³ increase in PM_2.5 concentrations attributable to SHS after controlling for the time of day and day of week.

Conclusions

These results indicate that the commonly proposed practice of maintaining open sliding walls as a means of free air exchange does not lead to the elimination of employee exposure to tobacco specific carcinogens attributable to workplace SHS.     

Derivación a las consultas de gastroenterología desde atención primaria: evaluación de dos programas

Objectives

To analyze the effect of implementing a high-resolution clinic (HRC) and an increasing resolution capacity program in primary care (IRCPPC) for referrals to a gastroenterology outpatient clinic from primary care and the resources used.

Methods

A retrospective and observational study based on a review of referral sheets and databases was performed. We analyzed the number and reason for referrals, delay times and resource consumption in two periods: before (first 4 months of 2007) and after (first 4 months of 2009) the launch of the IRCPPC and HRC.

Results

In the first and second periods, 881 and 1076 patients, respectively, referred from primary health care were evaluated in the gastroenterology clinic, with a decrease in the delay time in the second period (80.8 ± 64.34 days vs 36.1 ± 29.12 days, p < 0.001). The most frequent reasons for referral were dyspepsia (27.7%), high-risk of colorectal cancer (17.1%), disturbance of bowel rhythm (18.2%), abdominal pain (16%), and gastroesophageal reflux (11.2%), with no differences between the two periods. Although delay times until the first visit (10.8 ± 9.03 days vs 42.8 ± 28.67 days, p < 0.001) and until discharge (39.6 ± 80.65 days vs 128.6 ± 135.34 days, p < 0.001) were lower in referrals to the HRC, the number of visits (3.6 ± 2.20 vs 3.2 ± 1.95, p = 0.015) and the cost of referrals (592.7 ± 421.50 € vs 486.0 ± 309.66 €, p < 0.001) was higher.

Conclusions

In the study period the number of referrals increased, while the delay time decreased. Although the HRC reduces delay times, it is associated with an increase in health resource use.     

Evaluating the efficacy of different smoking policies in restaurants and bars in Beijing,China: A four-year follow-up study

Introduction

In 2006, the World Health Organization Framework Convention on Tobacco Control became effective in mainland China. In 2007, advocacy on voluntary smoking bans in restaurants was initiated in Beijing, and in 2008 the Beijing government implemented a smoking regulation, requiring big restaurants to prohibit or restrict smoking.

Objectives

To evaluate the efficacy of different smoking policies adopted by Beijing restaurants and bars from 2006 to 2010.

Methods

The study conducted field observations of patron smoking behavior and monitored fine particulate matter from secondhand smoke (SHS PM) from 91, 85, 94 and 79 Beijing restaurants and bars in 2006, 2007, 2008 and 2010, respectively, during peak-patronage times, with overlaps of venues during each two years. Area nicotine sampling during peak patronage times and servers’ personal nicotine sampling during their working shifts were also conducted in 2010.

Results

Smoking was nominally prohibited or restricted in 18% of restaurants and bars monitored in 2006, in 11% of venues in 2007, in 83% of venues in 2008, and in 69% of venues in 2010. However, smoking was observed in more than 40% of the nominal nonsmoking venues/sections in 2008 and 2010. The median of observed patron active smoker density (ASD) was 0.24, 0.27, 0.00 and 0.10 active smokers per 100 m³ in 2006, 2007, 2008 and 2010, respectively. The median of SHS PM concentrations was 53, 83, 18 and 27 μg/m³, respectively. In 2010, both the median SHS PM and air nicotine concentrations in designated nonsmoking sections were about 40% of those in designated smoking sections, according to simultaneous sampling in both sections. Servers’ personal exposure to air nicotine was quite similar in venues with different nominal smoking policies. In the 15 venues followed from 2006 to 2010, SHS PM concentrations changed randomly from 2006 to 2007, decreased in most venues in 2008, and then increased to some extent in 2010.

Conclusion

Voluntary smoking policy is rarely adopted and cannot protect people from SHS exposure in restaurants and bars. The 2008 Beijing governmental smoking regulation failed to significantly reduce SHS exposure shortly or two years after its implementation. Restricting smoking to designated sections cannot eliminate SHS exposure.     

Variación espacial de la exposición a contaminación atmosférica en la ciudad de Valencia y su relación con un índice de privación

Objective

To evaluate spatial variation in exposure to nitrogen dioxide (NO₂) air pollution in the city of Valencia, Spain, and its association with socioeconomic deprivation and age.

Methods

Census tract population data were obtained from the National Statistics Institute of Spain. Outdoor NO₂ was monitored in 100 sites in the study area, through the use of passive samplers, in three campaigns between 2002 and April 2004. Land use regression (LUR) was used to obtain a map of NO₂ levels. The LUR predictions were compared with the NO₂ level obtained by: a) the nearest sampler of the monitoring network, b) the nearest passive sampler, c) the mean distance-weighted levels of the samplers in the neighborhood, and d) the NO₂ level obtained by using Kriging. For each census tract, the NO₂ levels were obtained. The association of NO₂ air pollution exposure with population age (≥65 years) and the 5-category deprivation index was analyzed.

Results

The LUR models showed less error than the other prediction methods. The safety levels proposed by the World Health Organization were exceeded in more than 99% of the population. An inverse relationship was found between NO₂ levels and the deprivation index (β = –2.01 μg/m³ in the most deprived quintile compared with lower deprivation, 95%CI: –3.07; –0.95) and a direct relationship was found with age (β = 0.12 μg/m³ per unit increase in percentage of the population ≥ 65 years, 95%CI: 0.08; 0.16).

Conclusions

The method allowed pollution maps to be obtained and the association between NO₂ levels and sociodemographic characteristics to be described.     

La auditoría energética: una herramienta de gestión en atención primaria

Objective

The aim of this study was to evaluate the viability of energy audit as a management tool in primary care to improve the energy efficiency and environmental performance of a health center by reducing its operating costs.

Method

We conducted 55 energy audits in health centers from 2005-2010. The health centers were sized between 500 and 3,500 m², were located in health areas with 3,500 to 25,000 users, and were built between 1985 and 2007.

Results

With an average investment of 11,601€ per site, energy consumption can be reduced by 10,801 kWh per year, saving 2,961€ with a mean payback period of 3.92 years, and preventing emission of 7,010 kg of CO₂.

Conclusions

Energy auditing is a practical tool to reduce the operating and maintenance costs of health centers and of improving the comfort of the facilities.     

The effect of outdoor air and indoor human activity on mass concentrations of PM(10), PM(2.5), and PM(1) in a classroom

The 12-h mass concentration of PM₁₀, PM_2.5, and PM₁ was measured in a lecturing room by means of three co-located Harvard impactors. The filters were changed at 8 AM and at 8 PM to cover the periods of presence and absence of students. Concentrations were assessed by gravimetry. Ambient PM₁₀ data were available for corresponding 12-h intervals from the nearest state air-quality-monitoring network station. The data were pooled into four periods according to the presence and absence of students—Monday-Thursday day (workday daytime), Monday-Thursday night (workday night), Friday-Sunday day (weekend daytime), and Friday-Sunday night (weekend night). Average indoor workday daytime concentrations were 42.3, 21.9 and 13.7 μg m⁻³, workday night were 20.9, 19.1 and 15.2 μg m⁻³, weekend daytime were 21.9, 18.1 and 11.4 μg m⁻³, and weekend night were 24.5, 21.3, and 15.6 μg m⁻³ for PM₁₀, PM_2.5, and PM₁, respectively. The highest 12-h mean, median, and maximum (42.3, 43.0, and 76.2 μg m⁻³, respectively) indoor concentrations were recorded on workdays during the daytime for PM₁₀. The statistically significant (r=0.68,P<0.0009) correlation between the number of students per hour per day and the indoor coarse fraction calculated as PM_10−2.5 during daytime on workdays indicates that the presence of people is an important source of coarse particles indoor. On workdays, the daytime PM₁₀ indoor/outdoor ratio was positively associated (r=0.93) with an increasing indoor coarse fraction (PM_10-2.5), also indicating that an important portion of indoor PM₁₀ had its source inside the classroom. With the exception of the calculated coarse fraction (PM_10-2.5), all of the measured indoor particulate matter fractions were significantly highly correlated with outdoor PM₁₀ and negatively correlated with wind velocity, showing that outdoor levels of particles influence their indoor concentrations.     

Descripción de las agresiones sexuales atendidas en el servicio de urgencias de un centro hospitalario de referencia

Objective

To describe the factors related to adult sexual assaults attended in a referral hospital in the city of Barcelona (Spain).

Methods

We carried out an individual-based cross-sectional study of sexual assaults treated in the emergency department between 2005 and 2008.

Results

A total of 712 patients (95.5% female) were treated. The median age of assaulted women was 25 years. Complaints were made in 87.5% of cases and assaults were made by a single attacker in 84.5%. When the perpetrator was known, the profile of the victim (p ≤ 0.05) was as follows: the victim was assaulted at home (81.5%), the perpetrator acted alone (94.2%), the mechanism of aggression was penetration (89.3%) and the attack took place during the week (63.3%).

Conclusions

Analysis of sexual assaults allows for different risk groups to be established, which facilitates the development of specific protocols and guidelines for effective aid and full treatment.     

Cumulative exposure to particulate matter air pollution and long-term post-myocardial infarction outcomes

Introduction

Chronic environmental exposure to particulate matter < 2.5 μm in diameter (PM_2.5) has been associated with cardiovascular disease; however, the effect of air pollution on myocardial infarction (MI) survivors is not clear. We studied the association of chronic exposure to PM_2.5 with death and recurrent cardiovascular events in MI survivors.

Methods

Consecutive patients aged ≤ 65 years admitted to all medical centers in central Israel after first-MI in 1992–1993 were followed through 2005 for cardiovascular events and 2011 for survival. Data on sociodemographic and prognostic factors were collected at baseline and during follow-up. Residential exposure to PM_2.5 was estimated for each patient based on data recorded at air quality monitoring stations. Cox and Andersen–Gill proportional hazards models were used to study the pollution-outcome association.

Results

Among the 1120 patients, 469 (41.9%) died and 541 (48.3%) experienced one or more recurrent cardiovascular event. The adjusted hazard ratios associated with a 10 μg/m³ increase in PM_2.5 exposure were 1.3 (95% CI 0.8–2.1) for death and 1.5 (95% CI 1.1–1.9) for multiple recurrences of cardiovascular events (MI, heart failure and stroke).

Conclusion

When adjustment for socio-demographic factors is performed, cumulative chronic exposure to PM_2.5 is positively associated with recurrence of cardiovascular events in patients after a first MI.     

Validación de los componentes del síndrome metabólico autodeclarados en un estudio de cohortes

Objectives

To assess the accuracy of self-reported data needed to constitute the metabolic syndrome in the University of Navarra Follow-Up [Seguimiento Universidad de Navarra (SUN)] cohort.

Methods

The SUN project is a multi-purpose prospective cohort, formed by more than 20,000 university graduates, followed-up using surface mail questionnaires every 2 years. In a sample of 287 cohort participants, self-reported data on the criteria needed to define the metabolic syndrome (waist circumference, blood pressure, triglycerides, high-density lipoprotein-cholesterol and glucose) were compared with the same biometric data obtained by blood tests or measured by trained medical staff. Intra-class correlation coefficients with 95% confidence intervals (95% CI), relative mean error and agreement limits according to the method proposed by Bland and Altman were calculated for each variable studied.

Results

High intraclass correlations were found for the values of waist circumference (r = 0.86, 95% CI: 0.80-0.90) and triglycerides (r = 0.71, 95%CI: 0.61-0.79). Moderate intraclass correlations were found (between 0.46 and 0.63) for the other factors. Relative mean errors were always < 2.5%, and >91% of values were within the limits of agreement for all variables.

Conclusions

The results suggest that self-declared data on the criteria of metabolic syndrome obtained in the SUN cohort, though with some caution, are sufficiently accurate to be used in epidemiological studies.     

Secondhand Tobacco Smoke Exposure in Open and Semi-Open Settings: A Systematic Review

Background: Some countries have recently extended smoke-free policies to particular outdoor settings; however, there is controversy regarding whether this is scientifically and ethically justifiable.Objectives: The objective of the present study was to review research on secondhand smoke (SHS) exposure in outdoor settings.Data sources: We conducted different searches in PubMed for the period prior to September 2012. We checked the references of the identified papers, and conducted a similar search in Google Scholar.Study selection: Our search terms included combinations of “secondhand smoke,” “environmental tobacco smoke,” “passive smoking” OR “tobacco smoke pollution” AND “outdoors” AND “PM” (particulate matter), “PM_2.5” (PM with diameter ≤ 2.5 µm), “respirable suspended particles,” “particulate matter,” “nicotine,” “CO” (carbon monoxide), “cotinine,” “marker,” “biomarker” OR “airborne marker.” In total, 18 articles and reports met the inclusion criteria.Results: Almost all studies used PM_2.5 concentration as an SHS marker. Mean PM_2.5 concentrations reported for outdoor smoking areas when smokers were present ranged from 8.32 to 124 µg/m³ at hospitality venues, and 4.60 to 17.80 µg/m³ at other locations. Mean PM_2.5 concentrations in smoke-free indoor settings near outdoor smoking areas ranged from 4 to 120.51 µg/m³. SHS levels increased when smokers were present, and outdoor and indoor SHS levels were related. Most studies reported a positive association between SHS measures and smoker density, enclosure of outdoor locations, wind conditions, and proximity to smokers.Conclusions: The available evidence indicates high SHS levels at some outdoor smoking areas and at adjacent smoke-free indoor areas. Further research and standardization of methodology is needed to determine whether smoke-free legislation should be extended to outdoor settings.     

Estimación de la exposición al humo ambiental de tabaco: revisión de cuestionarios utilizados en España

Introduction

In the last few years, health surveys and epidemiological studies on smoking have introduced questions on environmental tobacco smoke (ETS) exposure. However, a standardized questionnaire is lacking.

Methods

Between January and May 2008, we reviewed surveys containing items on ETS exposure carried out in Spain by public administrations, scientific societies and research institutes. The wording of the questions was reviewed and classified according to the study type, target population, geographical setting and place of exposure.

Results

We identified 27 surveys that included questions on passive smoking. Most were health surveys (81.5%) and were aimed at the general population (70.4%). The most frequent geographical setting consisted of autonomous regions (48.1%) and the most common place of exposure was the home (88.9%)

Discussion

The results show wide variability in the questions used. Questionnaire items on ETS exposure should be homogenized to allow comparison of the results of surveys.     

Air pollution exposure and self-reported cardiovascular disease

Background

Studies suggest that increases of fine particle concentrations (PM_2.5) could be linked with a rise in cardiovascular disease. With approximately 25% of American adults aged 30 and older reporting having either heart disease or hypertension it is possible that exposure to air pollution could have significant public health consequences. This study examined the relationship between PM_2.5 and the prevalence of self-reported hypertension and heart disease using data from a large nation-wide survey.

Study design

Adults, 30 years of age or older, who participated in the National Health Interview Survey (NHIS) from 1999 to 2005 were linked to annual PM_2.5 data from the US Environmental Protection Agency (N=132,224). Annual air quality estimates were averaged from monitors within 20 miles of the respondent's residential block group. Respondents who reported being told they had hypertension by a health professional on two or more separate occasions were defined as hypertensive. Heart disease was defined as answering, “yes” to one or more of three NHIS questions on heart disease.

Results

A 10 μg/m³ increase in PM_2.5 exposure was associated with a small elevated risk of hypertension (adjusted odds ratio (OR) 1.05, 95% confidence interval (CI) 1.00-1.10) risk of heart disease (1.08 95% CI 1.00-1.16). The association between PM_2.5 and hypertension was found in non-Hispanic white adults (OR 1.10 95% CI 1.04-1.17) but not in non-Hispanic black or Hispanic adults.

Conclusions

Findings from this study complement those from other studies and indicate that PM_2.5 adversely affects cardiovascular health. Our results are consistent with other studies in showing a small association between exposure to PM_2.5 and cardiovascular outcomes.     

Cadmium, mercury, and lead in kidney cortex of living kidney donors: Impact of different exposure sources,

Background

Most current knowledge on kidney concentrations of nephrotoxic metals like cadmium (Cd), mercury (Hg), or lead (Pb) comes from autopsy studies. Assessment of metal concentrations in kidney biopsies from living subjects can be combined with information about exposure sources like smoking, diet, and occupation supplied by the biopsied subjects themselves.

Objectives

To determine kidney concentrations of Cd, Hg, and Pb in living kidney donors, and assess associations with common exposure sources and background factors.

Methods

Metal concentrations were determined in 109 living kidney donors aged 24-70 years (median 51), using inductively coupled plasma-mass spectrometry (Cd and Pb) and cold vapor atomic fluorescence spectrometry (Hg). Smoking habits, occupation, dental amalgam, fish consumption, and iron stores were evaluated.

Results

The median kidney concentrations were 12.9 μg/g (wet weight) for cadmium, 0.21 μg/g for mercury, and 0.08 μg/g for lead. Kidney Cd increased by 3.9 μg/g for a 10 year increase in age, and by 3.7 μg/g for an extra 10 pack-years of smoking. Levels in non-smokers were similar to those found in the 1970s. Low iron stores (low serum ferritin) in women increased kidney Cd by 4.5 μg/g. Kidney Hg increased by 6% for every additional amalgam surface, but was not associated with fish consumption. Lead was unaffected by the background factors surveyed.

Conclusions

In Sweden, kidney Cd levels have decreased due to less smoking, while the impact of diet seems unchanged. Dental amalgam is the main determinant of kidney Hg. Kidney Pb levels are very low due to decreased exposure.     

Does area level socioeconomic status modify the effects of PM10 on preterm delivery?

Background

Air pollution has been one of the focal points for investigations of maternal health and birth, and an association has been found between air pollution and birth outcomes. Some individual-level risk factors of mothers have been identified as strong predictors of preterm delivery (PTD). Recent literature has shown that the neighborhood environment of the mother and child has an independent influence on birth outcomes that was not explained by individual-level risk factors.

Objective

This study explored the effects of maternal exposure to particulate air pollution (PM₁₀) and its relationship to the probability of preterm delivery (PTD) in Seoul, Korea. Our hypothesis was that PM₁₀ increased the probability of PTD, and that the area level socioeconomic status (SES), measured by monthly average household income, modified the PM₁₀ effects on PTD after controlling for individual-level risk factors such as individual-level SES.

Data and Method

Birth data from the Korean National Statistics Office consisted of records on 433,173 singleton births in the years 2000-2003, and included individual characteristics. Area-level characteristics were also controlled for in 25 administrative regions in Seoul. Maternal exposure to PM₁₀ was calculated at an individual level for each trimester using information from monitoring sites in residential areas. Hourly data on PM₁₀ for 1999-2003 were acquired from the National Institute of Environment Research. Birth outcome was dichotomously coded: term birth (gestation ≥37 weeks) or PTD (gestation <37 weeks). For multilevel analysis, we conducted a hierarchical logistic regression with a random intercept for each administrative area to account for the hierarchical nature of the data.

Results

We found that area-level SES modified the PM₁₀ effects on PTD, specifically among those who were in low SES areas. Results of multilevel analyses showed that an increase in PM₁₀ by 10 μg/m³ led to a statistically significant increase in the probability of PTD [3.12% (95% CI, 0.17-6.15)] during the 2nd trimester in the low-income group. Analyses using the stratified population found a 3.4% increase (95% CI, 0.31-6.58) in the probability of PTD during the 2nd trimester in areas with low income.

Conclusion

Mothers exposed to higher PM₁₀ in Seoul, Korea, had a higher probability of PTD. Individual-level characteristics had different effects on the probability of PTD depending on the area-level SES. Area-level SES modified the effect of PM₁₀ concentration on PTD.