Contrasting Health Outcomes following a Severe Smoke Episode and Ambient Air Pollution in Early Life: Findings from an Australian Data Linkage Cohort Study of Hospital Utilization

BACKGROUND

Episodic spikes in air pollution due to landscape fires are increasing, and their potential for longer term health impacts is uncertain.

OBJECTIVE

Our objective is to evaluate associations between exposure in utero and in infancy to severe pollution from a mine fire, background ambient air pollution, and subsequent hospital care.

METHODS

We linked health records of births, emergency department (ED) visits, and hospitalizations of children born in the Latrobe Valley, Australia, 2012-2015, which included a severe pollution episode from a mine fire (9 February 2014 to 25 March 2014). We assigned modeled exposure estimates for fire-related and ambient particulate matter with an aerodynamic diameter of 2.5 μ m (PM 2.5 ) to residential address. We used logistic regression to estimate associations with hospital visits for any cause and groupings of infectious, allergic, and respiratory conditions. Outcomes were assessed for the first year of life in the in utero cohort and the year following the fire in the infant cohort. We estimated exposure-response for both fire-related and ambient PM 2.5 and also employed inverse probability weighting using the propensity score to compare exposed and not/minimally exposed children.

RESULTS

Prenatal exposure to fire-related PM 2.5 was associated with ED presentations for allergies/skin rash [odds ratio ( OR ) = 1.34 , 95% confidence interval (CI): 1.01, 1.76 per 240   μ g / m 3 increase]. Exposure in utero to ambient PM 2.5 was associated with overall presentations (OR = 1.18 , 95% CI: 1.05, 1.33 per 1.4   μ g / m 3 ) and visits for infections (ED: OR = 1.13 , 95% CI: 0.98, 1.29; hospitalizations: OR = 1.23 , 95% CI: 1.00, 1.52). Exposure in infancy to fire-related PM 2.5 compared to no/minimal exposure, was associated with ED presentations for respiratory (OR = 1.37 , 95% CI: 1.05, 1.80) and infectious conditions (any: OR = 1.21 , 95% CI: 0.98, 1.49; respiratory-related: OR = 1.39 , 95% CI: 1.05, 1.83). Early life exposure to ambient PM 2.5 was associated with overall ED visits (OR = 1.17 , 95% CI: 1.05, 1.30 per 1.4   μ g / m 3 increase).

DISCUSSION

Higher episodic and lower ambient concentrations of PM 2.5 in early life were associated with visits for allergic, respiratory, and infectious conditions. Our findings also indicated differences in associations at the two developmental stages. https://doi.org/10.1289/EHP12238.

Primary and pharmaceutical care usage concurrent associations with a severe smoke episode and low ambient air pollution in early life

BACKGROUND

Due to climate change, landscape fires account for an increasing proportion of air pollution emissions, and their impacts on primary and pharmaceutical care are little understood.

OBJECTIVES

To evaluate associations between exposure in two early life periods to severe levels of PM_2.5 from a mine fire, background PM_2.5, and primary and pharmaceutical care.

METHODS

We linked records of births, general practitioner (GP) presentations and prescription dispensing for children born in the Latrobe Valley, Australia, 2012-2014, where a severe mine fire occurred in February-March 2014 in an area with otherwise low levels of ambient PM_2.5. We assigned modelled exposure estimates for fire-related (cumulative over the fire and peak 24-hour average) and annual ambient PM_2.5 to residential address. Associations with GP presentations and dispensing of prescribed medications in the first two years of life (exposure in utero) and in the two years post-fire (exposure in infancy) were estimated using two-pollutant quasi-Poisson regression models.

RESULTS

Exposure in utero to fire-related PM_2.5 was associated with an increase in systemic steroid dispensing (Cumulative: IRR = 1.11, 95%CI = 1.00-1.24 per 240 μg/m³; Peak: IRR = 1.15, 95%CI = 1.00-1.32 per 45 μg/m³), while exposure in infancy was associated with antibiotic dispensing (Cumulative: IRR = 1.05, 95%CI = 1.00-1.09; Peak: IRR = 1.06, 95%CI = 1.00-1.12). Exposure in infancy to ambient PM_2.5, despite relatively low levels from a global perspective (Median = 6.1 μg/m³), was associated with an increase in antibiotics (IRR = 1.10, 95%CI = 1.01-1.19 per 1.4 μg/m³) and in GP presentations (IRR = 1.05, 95%CI = 1.00-1.11), independently from exposure to the fire. We also observed differences in associations between sexes with GP presentations (stronger in girls) and steroid skin cream dispensing (stronger in boys).

DISCUSSION

Severe medium-term concentrations of PM_2.5 were linked with increased pharmaceutical treatment for infections, while chronic low levels were associated with increased prescriptions dispensed for infections and primary care usage. Our findings also indicated differences between sexes.

Why Tasmanian retailers stop selling tobacco and implications for tobacco control

INTRODUCTION

The retail availability of tobacco is at odds with the health harms associated with tobacco smoking and undermines tobacco control efforts. Evidence suggests ease of access to tobacco through retail outlets contributes to smoking prevalence.

OBJECTIVE

This study aimed to understand why retailers stop selling tobacco and explore possible implications for tobacco control.

METHODS

The Tobacco Licensing Database maintained by the Department of Health Tasmania was used to identify and recruit past retailers who no longer held licences. Semistructured interviews were conducted to explore business demographics and the reasons they stopped selling tobacco. Interview findings were analysed using a thematic framework.

RESULTS

Twenty former tobacco retailers participated, representing all business types except specialist tobacconists and large supermarkets. Retailers gave multiple reasons for ending tobacco sales, related to business considerations, security, tobacco regulations, ethics and health. Most often, the decision was business-related; health or ethical considerations were rarely a factor. Most retailers felt they played no role in mitigating tobacco-related harm.

CONCLUSIONS

This study provides insights into factors that make tobacco sales unattractive or unfeasible for low-volume outlets and may inform supply-focused tobacco control policy. A campaign that emphasises the possible business benefits of ending tobacco sales in favour of other higher-margin products may support retailers to transition away from tobacco sales. The regulatory obligations of selling tobacco are disincentives and create a less favourable retail environment.

Associations between respiratory and vascular function in early childhood

BACKGROUND AND OBJECTIVE

The link between respiratory and vascular health is well documented in adult populations. Impaired lung function is consistently associated with thicker arteries and higher incidence of cardiovascular disease. However, there are limited data on this relationship in young children and the studies that exist have focussed on populations at high risk of cardiorespiratory morbidity. We determined if an association exists between respiratory and cardiovascular function in young children and, if so, whether it is confounded by known cardiorespiratory risk factors.

METHODS

Respiratory and vascular data from a prospective cohort study established to evaluate the health implications 3 years after coal mine fire smoke exposure in children aged 3-5 years were used. Respiratory function was measured using the forced oscillation technique and included resistance at 5 Hz (R₅ ), reactance at 5 Hz (X₅ ) and area under the reactance curve (AX). Vascular health was measured by carotid intima-media thickness (ultrasound) and pulse wave velocity (arterial tonometry). Regression analyses were used to examine the relationship between the respiratory Z-scores and cardiovascular measures. Subsequent analyses were adjusted for potential confounding by maternal smoking during pregnancy, maternal education and exposure to fine particulate matter <2.5 μm in aerodynamic diameter (PM_2.5 ).

RESULTS

Peripheral lung function (X₅ and AX), but not respiratory system resistance (R₅ ), was associated with vascular function. Adjustment for maternal smoking, maternal education and early life exposure to PM_2.5 had minimal effect on these associations.

CONCLUSION

These observations suggest that peripheral lung stiffness is associated with vascular stiffness and that this relationship is established early in life.

Respiratory and atopic conditions in children two to four years after the 2014 Hazelwood coalmine fire

OBJECTIVE

To evaluate associations between exposure during early life to mine fire smoke and parent-reported indicators of respiratory and atopic illness 2-4 years later.

DESIGN, SETTING

The Hazelwood coalmine fire exposed a regional Australian community to markedly increased air pollution during February - March 2014. During June 2016 - October 2018 we conducted a prospective cohort study of children from the Latrobe Valley.

PARTICIPANTS

Seventy-nine children exposed to smoke in utero, 81 exposed during early childhood (0-2 years of age), and 129 children conceived after the fire (ie, unexposed).

EXPOSURE

Individualised mean daily and peak 24-hour fire-attributable fine particulate matter (PM_2.5 ) exposure during the fire period, based on modelled air quality and time-activity data.

MAIN OUTCOME MEASURES

Parent-reported symptoms, medications use, and contacts with medical professionals, collected in monthly online diaries for 29 months, 2-4 years after the fire.

RESULTS

In the in utero exposure analysis (2678 monthly diaries for 160 children exposed in utero or unexposed), each 10 μg/m³ increase in mean daily PM_2.5 exposure was associated with increased reports of runny nose/cough (relative risk [RR], 1.09; 95% CI, 1.02-1.17), wheeze (RR, 1.56; 95% CI, 1.18-2.07), seeking health professional advice (RR, 1.17; 95% CI 1.06-1.29), and doctor diagnoses of upper respiratory tract infections, cold or flu (RR, 1.35; 95% CI, 1.14-1.60). Associations with peak 24-hour PM_2.5 exposure were similar. In the early childhood exposure analysis (3290 diaries for 210 children exposed during early childhood, or unexposed), each 100 μg/m³ increase in peak 24-hour PM_2.5 exposure was associated with increased use of asthma inhalers (RR, 1.26; 95% CI, 1.01-1.58).

CONCLUSIONS

Exposure to mine fire smoke in utero was associated with increased reports by parents of respiratory infections and wheeze in their children 2-4 years later.

Maternal exposure to fine particulate matter from a large coal mine fire is associated with gestational diabetes mellitus: A prospective cohort study

BACKGROUND

In 2014, the Hazelwood coal mine fire was an unprecedented event that resulted in a six-week period of poor air quality in the Latrobe Valley in regional Australia. We aimed to determine whether maternal exposure to fine particulate matter in coal mine fire smoke was associated with selected obstetric complications, including gestational diabetes mellitus, hypertensive disorders of pregnancy and abnormal placentation.

METHODS

We defined a complete cohort of pregnant women with births >20 weeks in the Latrobe Valley from March 1, 2012-Dec 31, 2015 utilising administrative perinatal data. Average and peak fine particulate matter (PM_2.5) was assigned to residential address at delivery using a chemical transport model. Maternal, meteorological and temporal variables were included in final log-binomial regression models.

RESULTS

3612 singleton pregnancies were included in the analysis; 766 were exposed to the smoke event. Average maternal PM_2.5 exposure was 4.4 μg/m³ (SD 7.7; IQR 2.12). Average peak PM_2.5 exposure was 44.9 μg/m³ (SD 57.1; IQR 35.0). An interquartile range increase in peak PM_2.5 was associated with a 16% increased likelihood of gestational diabetes mellitus (95%CI 1.09, 1.22; <0.0001). Whereas, an interquartile range increase in average PM_2.5 was associated with a 7% increased likelihood of gestational diabetes mellitus (95%CI 1.03, 1.10; <0.0001). Second trimester exposure was of critical importance. No association for hypertensive disorders or abnormal placentation was observed.

CONCLUSION

this is the first study to examine obstetric complications relating to a discrete smoke event. These findings may guide the public health response to future similar events.

Roof cavity dust as an exposure proxy for extreme air pollution events

Understanding exposure to air pollution during extreme events such as fire emergencies is critical for assessing their potential health impacts. However, air pollution emergencies often affect places without a network of air quality monitoring and characterising exposure retrospectively is methodologically challenging due to the complex behaviour of smoke and other air pollutants. Here we test the potential of roof cavity (attic) dust to act as a robust household-level exposure proxy, using a major air pollution event associated with a coal mine fire in the Latrobe Valley, Australia, as an illustrative study. To assess the relationship between roof cavity dust composition and mine fire exposure, we analysed the elemental and polycyclic aromatic hydrocarbon composition of roof cavity dust (<150μm) from 39 homes along a gradient of exposure to the mine fire plume. These homes were grouped into 12 zones along this exposure gradient: eight zones across Morwell, where mine fire impacts were greatest, and four in other Latrobe Valley towns at increasing distance from the fire. We identified two elements-barium and magnesium-as 'chemical markers' that show a clear and theoretically grounded relationship with the brown coal mine fire plume exposure. This relationship is robust to the influence of plausible confounders and contrasts with other, non-mine fire related elements, which showed distinct and varied distributional patterns. We conclude that targeted components of roof cavity dust can be a useful empirical marker of household exposure to severe air pollution events and their use could support epidemiological studies by providing spatially-resolved exposure estimates post-event.

Maternal exposure to fine particulate matter from a coal mine fire and birth outcomes in Victoria, Australia

INTRODUCTION

The Hazelwood coal mine fire was an unprecedented event in Australian history that resulted in the surrounding towns in regional Victoria being covered in plumes of smoke and ash for six weeks in 2014. Evidence concerning adverse reproductive impacts associated with maternal exposure to ambient air pollution is expanding. Gaps remain regarding the relative impact of acute changes in outdoor air quality lasting days to months, such as that resulting from coal mine fires.

METHODS

Routinely collected perinatal data was used to define a complete cohort of singleton babies born within the affected region. Maternal average, and peak, fine particulate matter (PM_2.5) was assigned to residential address at time of delivery using a chemical transport model. Maternal, infant, meteorological and temporal variables were adjusted for in final linear and log-binomial regression models.

RESULTS

There were a total of 3591 singleton livebirths during the study period; 763 of which were in utero during the coal mine fire. Average PM_2.5 exposure was 4.4 μg/m³ (median 1.9; IQR 2.1 μg/m³) and peak was 45.0 μg/m³ (median 30.4; IQR 35.1 μg/m³). There was no association between coal mine fire-attributable PM_2.5 and fetal growth or gestational maturity outcomes. However, there was weak evidence that gestational diabetes mellitus was an effect modifier in the relationship between maternal PM_2.5 exposure and birth weight. Babies born to exposed gestational diabetic mothers were 97 g heavier per 10 μg/m³ increase in average PM_2.5 exposure (95%CI 74, 120 g). No association was observed among mothers without gestational diabetes.

CONCLUSION

Maternal exposure to fine particulate matter resulting from the 2014 Hazelwood coal mine fire did not appear to adversely effect fetal maturity. However, there was weak evidence of a trophic response among babies born to exposed mothers with gestational diabetes, a possible susceptibility that requires further exploration.

The retail availability of tobacco in Tasmania: evidence for a socio-economic and geographical gradient

OBJECTIVES

To describe the retail availability of tobacco and to examine the association between tobacco outlet density and area-level remoteness and socio-economic status classification in Tasmania.

DESIGN

Ecological cross-sectional study; analysis of tobacco retail outlet data collected by the Department of Health and Human Services (Tasmania) according to area-level (Statistical Areas Level 2) remoteness (defined by the Remoteness Structure of the Australian Statistical Geographical Standard) and socio-economic status (defined by the 2011 Australian Bureau of Statistics Index of Relative Socioeconomic Advantage and Disadvantage).

MAIN OUTCOME MEASURE

Tobacco retail outlet density per 1000 residents.

RESULTS

On 31 December 2016, there were 1.54 tobacco retail outlets per 1000 persons. The density of outlets was 79% greater in suburbs or towns in outer regional, remote and very remote Tasmania than in inner regional Tasmania (rate ratio [RR], 1.79; 95% confidence Interval [CI], 1.29-2.50; P < 0.001). Suburbs or towns in Tasmania with the greatest socio-economic disadvantage had more than twice the number of tobacco outlets per 1000 people as areas of least disadvantage (RR, 2.30; 95% CI, 1.32-4.21; P = 0.014).

CONCLUSIONS

A disproportionate concentration of tobacco retail outlets in regional and remote Tasmania and in areas of lowest socio-economic status is evident. Our findings are consistent with those of analyses in New South Wales and Western Australia. Progressive tobacco retail restrictions have been proposed as the next frontier in tobacco control. However, the intended and unintended consequences of such policies need to be investigated, particularly for socio-economically deprived and rural areas.

Maternal exposure to short-to medium-term outdoor air pollution and obstetric and neonatal outcomes: A systematic review

BACKGROUND

Little is known about the impacts of maternal exposure to acute episodes of outdoor air pollution, such as that resulting from wildfires, on obstetric and neonatal outcomes. This systematic review aims to synthesise the existing literature exploring the relationship between maternal exposure to short-to medium-term changes in outdoor air quality and obstetric and neonatal outcomes.

METHODS

A systematic search of peer-reviewed articles using PubMed, Cochrane Library, EMBASE, ScienceDirect, Web of Science, ProQuest, GreenFILE and Scopus was conducted in January 2018 using selected search terms. Quality of included studies were assessed using the Newcastle Ottawa Scale.

RESULTS

Eleven studies were included; eight assessed the impact of maternal exposure to air pollution exacerbation events, such as wildfires, oil well fires and volcanic eruptions, and three assessed the impact of improvement events, such as the 2018 Beijing Olympics and closure of industrial activities, on obstetric and neonatal outcomes. Studies were highly heterogenous in methodology. Six studies found a significant association between acute changes in air quality and markers of fetal growth restriction, while two did not. Three studies found an adverse association between acute changes in air quality and markers of gestational maturity, and one did not.

CONCLUSION

Overall, there is some evidence that maternal exposure to acute changes in air quality of short-to medium-term duration increases the risk of fetal growth restriction and preterm birth. The relationship for other adverse obstetric or neonatal outcomes is less clear.

A cross-sectional survey of environmental health in remote Aboriginal communities in Western Australia

INTRODUCTION

The Australian Aboriginal population experiences significantly poorer health than the non-Aboriginal population. The contribution of environmental risk factors in remote communities to this health disparity is poorly understood.

OBJECTIVE

To describe and quantify major environmental risk factors and associated health outcomes in remote Aboriginal communities in Western Australia.

METHODS

The association between environmental health indicators, community infrastructure and reported health outcomes was analysed using linear and logistic regression of survey data.

RESULTS

Housing/overcrowding was significantly associated with increased reports of hearing/eyesight (OR 3.01 95 % CI 1.58-5.73), skin (OR 2.71 95 % CI 1.31-5.60), gastrointestinal (OR 3.51 95 % CI 1.49-8.26) and flu/colds (OR 2.47 95 % CI 1.27-4.78) as health concerns. Dust was significantly associated with hearing/eyesight (OR 3.16 95 % CI 1.82-5.48), asthma/respiratory (OR 2.48 95 % CI 1.43-4.29) and flu/colds (OR 3.31 95 % CI 1.88-5.86) as health concerns.

CONCLUSION

Poor environmental health is prevalent in remote Aboriginal communities and requires further delineation to inform environmental health policy.