Western Australia Research Articles

GPS telemetry facilitates the identification of forage plant species for endangered Carnaby’s cockatoos (Zanda latirostris) at inland breeding sites and post-breeding dispersal locations in Western Australia

Carnaby’s cockatoos (Zanda latirostris) are an endangered species that has experienced major loss of habitat over the past century. Proponents seeking land clearing approval that may impact Carnaby’s cockatoos need to provide detailed habitat assessment. However, the current forage species list is outdated and generally restricted to the Swan Coastal Plain rather than the Carnaby’s full distribution range. This study provides an updated forage list, including the Swan Coastal Plain and much of the Carnaby’s breeding and non-breeding areas outside this region. Carnaby’s cockatoos were captured and satellite tagged, at five breeding sites in the wheatbelt and Great Southern areas in Western Australia (between 2017 and 2022). Spatial data collected from the tags facilitated the identification of forage plants used by Carnaby’s cockatoos. A total of 44 ‘new’ native plant species were identified as Carnaby’s cockatoo forage species, including five genera that have not previously been recorded. The updated forage list will inform proponents and regulators on the potential use of habitat patches by Carnaby’s cockatoos, aiding the referral process and enabling the protection and conservation of important and diminishing habitat resources.

Addressing Uncertainty in Renewable Energy Integration for Western Australia’s Mining Sector: A Robust Optimization Approach

The mining industry is a key contributor to Western Australia’s economy, with over 130 mining operations that produce critical minerals such as iron ore, gold, and lithium. Ensuring a reliable and continuous energy supply is vital for these operations. This paper addresses the challenges and opportunities of integrating renewable energy sources into isolated power systems, particularly under uncertainties associated with renewable energy generation and demand. A robust optimization approach is developed to model a multi-source hybrid energy system that considers risk-averse, risk-neutral, and risk-seeking strategies. These strategies address power demand and renewable energy supply uncertainties, ensuring system reliability under various risk scenarios. The optimization framework, formulated as a mixed integer linear programming problem and implemented in Python using the Gurobi Optimizer, integrates renewable energy sources such as wind turbines, photovoltaic arrays, and demand response programs alongside traditional diesel generators, boilers, combined heat and power units, and water desalination. The model ensures reliable access to electricity, heat, and water while minimizing operational costs and reducing reliance on fossil fuels. A comprehensive sensitivity analysis further examines the impact of uncertainty margins and the value of a lost load on the total system cost, providing insights into how different risk strategies affect system performance and cost-efficiency. The results are validated through three case studies demonstrating the effectiveness of the proposed approach in enhancing the resilience and sustainability of isolated power systems in the mining sector. Significant improvements in reliability, scalability, and economic performance are observed, with the sensitivity analysis highlighting the critical trade-offs between cost and reliability under varying uncertainty conditions.

Preparing the Future Public Health Workforce: Fostering Global Citizenship Through the Relational Employability Framework—Insights from Two Case Studies

A well-prepared public health workforce is essential for reducing disease burdens and improving population health, necessitating an education that addresses global and complex challenges. This paper explores the integration of the Relational Employability Framework in public health education as a tool to foster critical reflection and cultivate global citizenship among students and graduates. Global citizenship encompasses the social, political, environmental and economic actions of globally conscious individuals and communities, recognising that individuals operate within diverse local and global networks. Relational employability expands traditional notions of graduate employability, incorporating not only foundational career development and human interactions but also connections with more-than-human elements, including ecologies, technologies and materials. Our research, conducted at Edith Cowan University in Perth, Western Australia, involved two case studies using qualitative interviews. Case Study 1, drawn from the Cook’s doctoral research, explored student experiences with the Relational Employability Framework within an undergraduate capstone unit. Case Study 2, a school-funded project, gathered graduate perspectives to inform ongoing curriculum development. The findings indicate that the Relational Employability Framework can help support the development of global citizenship through critical reflective practice, as students reported improved ability to engage with diverse perspectives and societal challenges, and graduates highlighted the framework’s role in supporting ethical, evidence-based practice in professional contexts. Additionally, the framework supported the development of a reflective mindset, which graduates said helped them make informed, value-based career decisions, thus advancing their professional growth. This study suggests that adopting a relational employability approach can prepare globally competent and reflective public health professionals and recommends its implementation across health and higher education.

Aridification and major geotectonic landscape change shaped an extraordinary species radiation across a world's extreme elevational gradient.

Understanding the profound influence of climatic and tectonic histories on adaptation and speciation is a crucial focus in biology research. While voyages like Humboldt's expedition shaped our understanding of adaptation, the origin of current biodiversity remains unclear - whether it arose in situ or through dispersal from analogous habitats. Situated in the geologically complex Australopacific region, our study focuses on Limbodessus diving beetles (Dytiscidae), a diverse genus distributed from underground aquifers in Western Australia to alpine meadows in New Guinea. Using low-coverage whole-genome sequencing, we established a time-calibrated phylogenetic tree, elucidating Limbodessus' origin in the mid-late Miocene, most likely in the Sahul continent (i.e., Australia and New Guinea) and western Pacific archipelagos. Our results provide evidence for parallel colonization and speciation at extreme altitudinal ends, driven by aridification in Australia, influencing subterranean colonization, and in situ diversification of alpine taxa by passive-uplifting of local biota in New Guinea. Furthermore, our findings highlight instances of subterranean speciation in isolated underground aquifers, marked by recurrent independent colonizations of this habitat.

Women’s Histories in a Digital World: An Exploration of Digital Archives, Family History, and Domestic Violence in Early Twentieth-Century Australia

In recent years, scholars have increasingly recognised the ways that colonialism, and related racism, embedded intergenerational trauma within families and communities. The role of domestic violence within families is widely accepted as important, but often treated separately. This article uses a case study from Western Australia, the life and death of Annie Grigo Dost, to explore the dynamics of both issues. Importantly, it also critiques the presentation of complex colonial family histories within a range of digital platforms, especially Ancestry.com. Such platforms obscure complex family dynamics, enforcing normative (often Westernised and highly gendered) digital frameworks for data, and consequently for stories about the past. This article offers an important critique of the ways that Ancestry.com in particular seems to actively sanitise family history, and the ways that they may be doing a disservice to their customers, who may want to acknowledge a more complex, critical family history.

Movements of adult and fledgling Carnaby’s Cockatoos (Zanda latirostris Carnaby, 1948) from eleven breeding areas throughout their range

Context Carnaby’s Cockatoo is an endangered species and the subject of a recovery plan. Aims Our study examined movements of adult and fledgling Carnaby’s Cockatoos from 11 breeding populations in southwestern Australia to establish where the cockatoos spent the non-breeding season (February–May) and sub-adult life-stage. Methods Data were collected on point-to-point movements from re-sightings and recoveries of cockatoos individually marked with patagial tags or leg bands. Sites were mostly located in the wheatbelt of Western Australia. Distribution patterns in the breeding and non-breeding seasons, including nesting sites were derived from location data from the Department of Biodiversity, Conservation and Attractions’ Threatened and Priority Database. Key results After breeding, adults and their fledglings moved from breeding areas to higher rainfall areas closer to the west and south coasts of south-western Australia where the food supply is greater and more reliable. Sub-adult cockatoos roam much more widely than adults and utilize foraging habitat not previously recognized as being important to this species. Conclusions Important foraging habitat and locations have been identified for breeding populations in the north and south of the range of Carnaby’s Cockatoos. Implications More conservation attention needs to be focussed on locating additional breeding populations, assessing the viability of these populations, and the extent and condition of their nesting and foraging habitat used during their non-breeding season. Conservation of Carnaby’s Cockatoo depends on the maintenance of remnant native vegetation and revegetation of nesting and foraging habitat throughout its range.

Enablers and barriers of implementing a whole school approach to ovulatory menstrual health literacy: a case study of a single-sex school in Western Australia

AbstractMy Vital Cycles® is a holistic ovulatory menstrual health literacy program for adolescent females. A whole school approach was used when trialled in one single-sex secondary school in Perth Australia. This study investigated the enablers and barriers for its future implementation from the perspective of the school’s teachers, nurses and psychologists. The design was a pre-trial survey of ovulatory menstrual health knowledge and attitudes, followed by post-trial interviews and focus group discussions (FGDs). In the pre-trial survey, 12 school staff demonstrated positive attitudes to ovulatory menstrual health; sound anatomical knowledge; but limited knowledge of cycle patterns. There were two FGDs with five participants and eight post-trial semi-structured interviews, giving 13 school staff in total. Deductive thematic analysis identified 14 themes within a whole school approach framework, specifically: policies and resources; community partnerships; curriculum; social-emotional environment; and school health services. Enablers included school staff’s positive attitudes; the program’s validated materials; its curricular alignment; and address of stigma. Barriers included school staff’s need for professional development; extending the program over years; Health and Science silos; dependence on school leadership; and challenges of building community partnerships. Co-design with school leadership and staff to enhance opportunities for a whole school approach is recommended for future implementation.

Embodied Thermal Insecurity and Counter‐Hegemonic Heat Mapping

AbstractLived experiences with urban heat are often rendered invisible, shrouded under the cloak of neoliberal resilience discourse and sanitised heat mapping and messaging. This is particularly tragic for disadvantaged at‐risk populations in white, settler colonial contexts where heat tolerance is worn as a badge of honour. Here, drawing upon semi‐structured interviews and focus group discussions in Perth, Western Australia, and with feminist emphasis on the embodied, the everyday, and bodily difference, we illustrate how corporeal thermal insecurities among rough sleepers, people with disabilities, and across intersectional disenfranchisement immobilise and dehumanise. By employing the logic of structures of violence to thermal suffering, we reveal how housing and energy precarity exacerbate entrenched racism and normalised discrimination. Our aim is to expand current debates on heat action plans (HAPs) and cool refuges by examining what “better weathering” could mean in practice, via the materialities of heated urban bodies (HUBs) and to demonstrate how such counter‐hegemonic heat mapping serves as a corporeal critique of the neoliberal resilient subject.

The Indo–Pacific Pollen Database – a Neotoma constituent database

Abstract. The Indo–Pacific Pollen Database (IPPD) is the brainchild of the late professor Geoffrey Hope, who gathered pollen records from across the region to ensure their preservation for future generations of palaeoecologists. This noble aim is now being fulfilled by integrating the IPPD into the online Neotoma Paleoecology Database, making this compilation available for public use. Here we explore the database in depth and suggest directions for future research. The IPPD comprises 226 fossil pollen records, most postdating 20 ka but with some extending as far back as 50 ka or further. Over 80 % of the records are Australian, with a fairly even distribution between the different Australian geographical regions, with the notable exception being Western Australia, which is only represented by three records. The records are also well distributed in the modern climate space, with the largest gap being in drier regions due to preservation issues. However, many of the records contain few samples or have fewer than five chronology control points, such as radiocarbon, luminescence or Pb-210, for the younger sequences. Average deposition time for the whole database, counted as years per centimetre, is 64.8 yr cm−1, with 61 % of the records having a deposition time shorter than 50 yr cm−1. The slowest deposition time by geographical region occurs on Australia's east coast, while the fastest times are from the western Pacific. Overall, Australia has a slower deposition time than the rest of the Indo–Pacific region. The IPPD offers many exciting research opportunities to investigate past regional vegetation changes and associated drivers, including contrasting the impact of the first human arrival and European colonisation on vegetation. Examining spatiotemporal patterns of diversity and compositional turnover/rate of change, land cover reconstructions, and plant functional or trait diversity are other avenues of potential research, amongst many others. Merging the IPPD into Neotoma also facilitates inclusion of data from the Indo–Pacific region into global syntheses.

Evaluation of the Pregnancy to Parenthood program: A dyadic intervention for mothers with perinatal mental disorders and their infants.

Dyadic interventions targeting maternal mental health and the mother-infant relationship in the perinatal period are critical due to the potential consequences of perinatal mental illness and relational disturbance for the mother, the infant, and their family. This paper describes the Pregnancy to Parenthood (P2P) model of care, a dyadic mother-infant community-based program designed to support vulnerable families in Western Australia in the context of an identified need to build workforce capacity. A pragmatic service evaluation study was conducted by analyzing routine clinical data collected from 105 dyads who completed pre- and post-intervention measures, including the Edinburgh Postnatal Depression Scale (EPDS), Perinatal Anxiety Screening Scale (PASS), and the Mother Object Relations Scale-Short Form (MORS-SF). Reliable change index and cut-off analyses indicated a clinically reliable pre-post reduction in perinatal depressive and anxiety symptoms for 71% and 68% of the sample, respectively. Significant pre-post improvements with medium effect sizes (r=-.46, r=-.32) were found for caregiving representations on the MORS-SF, suggesting representations became more balanced. These results provide provisional evidence that the P2P model of care may be effective in improving maternal mental health and caregiving representations. Further research is required to evaluate the efficacy of P2P in relation to enhancing family well-being, and to inform policy and mental health service development.

Drought in south-west Australia links to urban immigration across multiple avian taxa

Background Urban areas are a significant and rapidly expanding part of the global landscape. Urban expansion occurs alongside climate change, with both linked to declines in native species. However, urban environments can offer alternative resources during extreme climatic events such as droughts. Aims We sought to identify bird species that had an increased presence in the major urban center of south-west Western Australia during a climate anomaly characterized by record low rainfall and high temperatures. Methods Using eBird data, we analyzed changes in the reporting rates of all bird species in the period from January 2019 to August 2024. Generalized linear models were used to assess the influence of cumulative 6-month, 12-month, and 18-month rainfall on species reporting rates. Key results Reporting rates increased dramatically (up to nine times higher than average) around the time of the drought, before reducing back to the average once the drought was broken for four species: (1) the black-shouldered kite; (2) the black-tailed native-hen; (3) the tawny-crowned honeyeater; and (4) the western spinebill. Cumulative 6-month rainfall was a strong predictor for the raptor and the two honeyeaters. Other similar species showed no significant change in reporting rate, suggesting the effect is highly species dependent. Conclusions Multiple different types of birds may utilize urban areas during drought events. Further research is needed to identify what drives movement of wildlife in response to such events, and the type of urban resources the birds are using. Implications Urban ecosystems should be integrated into broader conservation plans to support species through the interacting challenges posed by climate change and urbanization.

Make the Right Call: formative evaluation for a water safety programme for adults in Western Australia.

Preventing drowning in adults is a complex, multifaceted injury prevention issue. The adult drowning rate in Australia is continuing to rise. In 2023, more than half of those who drowned were aged over 45 years. While there has been a call for robust, evidence-informed drowning prevention interventions across the life course, evidence of evaluated, drowning prevention programmes for adults is lacking. For more than a decade, drowning prevention researchers and practitioners in Western Australia (WA) have worked in partnership to design and evaluate evidence-informed programmes. This paper describes formative research to develop 'Make the Right Call' (MTRC), an adult water safety programme in WA. A staged, mixed-methods, formative evaluation was undertaken to inform the design of MTRC. The approach involved cluster analysis of coronial data 2008-2018 (n = 93), interviews with adults aged 45-64 years (n = 10) and 65 years and older (n = 15), theory mapping, survey design, content and face validity testing of a baseline questionnaire with content experts (n = 11) and a refined instrument to collect knowledge, and data on norms and water-based activity. The subsequent MTRC programme comprised a media campaign, community swimming and safety classes, lifejacket trade-in, subsidised first-aid training and community education. The results of each stage informed the design and evaluation of a new evidence-informed and theory-driven drowning prevention programme for adults aged 45 years and older, delivered by the peak drowning prevention agency in WA, Royal Life Saving Western Australia. An investment in mixed-methods research by the partnership added rigour and credibility to the programme and evaluation design. To the best of our knowledge, this is the first adult water safety programme to apply a theory-driven, evidence-informed approach to its development, implementation and evaluation. The partnership was vital in maximising and accelerating the acceptable transfer of results to enhance knowledge creation and, ultimately, the design of the MTRC drowning prevention programme.

Identifying critical periods of susceptibility for maternal exposure to biothermal stress and the risks of stillbirth and spontaneous preterm birth in Western Australia.

A few studies investigated critical periods of temperature and the risks of stillbirth and preterm birth. This study aimed to identify critical periods of composite biothermal stress (Universal Thermal Climate Index, UTCI) for stillbirth and spontaneous preterm birth (sPTB). From the Midwives Notification System, 415,271 singleton births between 1st January 2000 and 31st December 2015 were linked to spatiotemporal UTCI in Western Australia. Covariate-adjusted weekly and monthly distributed lag non-linear Cox regression from twelve weeks before conception to birth were performed. Relative to median exposure (14.2 °C), extreme UTCI levels (1st-10th and 90th-99th centiles) were associated with higher hazards of stillbirth and sPTB, especially stronger at lower than higher exposures. Critical susceptible periods at 1st centile (10.2°C) exposure were found during gestational weeks 21-42 with the strongest hazard of 1.14 (95% CI 1.03, 1.27) in the 42nd week for stillbirth and during gestational weeks 26-36 with the strongest hazard of 1.09 (95% CI 1.06, 1.12) in the 36th week for sPTB. Monthly exposure showed a similar pattern but with greater magnitude. Mid to late gestation showed critical susceptible periods of biothermal stress on the birth outcomes, suggesting further studies and timely climate-related healthcare interventions.

What drives the overall technical efficiency of farm businesses in the Wheatbelt of Western Australia? Analysis of persistent and transient efficiencies in the presence of firm effects

AbstractThis study enhances our comprehension of the performance of farm businesses in Western Australia by estimating persistent and transient technical efficiency measures in the presence of firm‐level effects. The analysis is based on a balanced panel data set of 54 farm businesses from the years 2002 to 2011. We employ Kumbhakar et al.'s (2014, Journal of Productivity Analysis, 41, 321) model to estimate persistent efficiency and firm effects separately, as well as Kumbhakar's and Heshmati's (1995, American Journal of Agricultural Economics, 77, 660) model where these two factors are confounded. Furthermore, we investigate the factors that influence transient and persistent technical efficiency. Our findings reveal that failing to differentiate between persistent technical efficiency and firm effects underestimates the estimates of persistent and overall technical efficiency. This underestimation may result in misguided policy recommendations for improving the technical performance of farm businesses. We also find that persistent efficiency dominates overall technical efficiency. The significant determinants of persistent overall technical efficiency include the regional rainfall zone where a farm business is located, the managerial competency of the farm operator denoted by their age and off‐farm activities. Off‐farm income plays a crucial role in determining transient technical efficiency.

Estimating vegetation structure and aboveground carbon storage in Western Australia using GEDI LiDAR, Landsat and Sentinel data

Abstract Worsening climate change impacts are amplifying the need for accurate estimates of vegetation structure and aboveground biomass density (AGBD) to assess changes in biodiversity and carbon storage. In Australia, increasing wildfire frequency and interest in the role of forests in the carbon cycle necessitates biomass mapping across large geographic extents to monitor forest change. The availability of spaceborne Light Detection and Ranging (LiDAR) optimised for vegetation structure mapping through the Global Ecosystem Dynamics Investigation (GEDI) provides an opportunity for large-scale forest AGBD estimates of higher accuracy. This study assessed the use of the GEDI canopy height product to predict woody AGBD across five vegetation types in Western Australia: tall eucalypt forests, eucalypt open‒woodlands, low-lying heathland, tropical eucalypt savannas, and tussock and hummock grasslands. Canopy height models were developed using random forest regressions trained on GEDI canopy height discrete point data. Predictor variables included spectral bands and vegetation indices derived from synthetic aperture radar (SAR) Sentinel‒1 data, and multispectral Landsat and Sentinel‒2 data. AGBD was subsequently estimated using power-law models derived by relating the predicted canopy heights to field AGBD plots. Mapping was conducted for 2020 and 2021. The accuracy of canopy height predictions varied with height quantiles; models underestimated the height of taller trees and overestimated the height of smaller trees. A similar underestimation and overestimation trend was observed for the AGBD estimates. The mean carbon stock was estimated at 69.0 ±12.0 MgCha-1 in the tall eucalypt forests of the Warren region; 33.8 ± 5.0 MgCha-1 for the open eucalypt woodlands in the South Jarrah region; 7.1 ± 1.4 MgCha-1 for the heathland and shrublands in the Geraldton Sandplains region; 43.9 ± 4.9 MgCha-1 for the Kimberley eucalypt savanna; and 3.9 ± 1.0 MgCha-1 for the Kimberley savanna grasslands. This approach provides a useful framework for the future development of this process for fire management, and habitat health monitoring.

It “bendy dis one”: recognising and building upon Australian Aboriginal students’ linguistic repertoires as educational resources

There is a considerable body of research documenting the languages First Nations children bring to school. However, despite language being a key factor impacting on educational outcomes, there is little research focussing on the students’ language use within schools outside specific learning contexts. Therefore, in this study we sought to explore the language resources used by Australian Aboriginal children at school, particularly those underexamined cohorts living in regional and remote locations. We examined how they used language in the classroom and in the playground, and with different audiences (e.g. peers vs teachers). Naturalistic language data were collected in seven schools located in different settings within Western Australia. 230 children and their teachers were recorded. The data show these students draw on their full linguistic repertoire when at school – moving between lighter or heavier varieties of Australian Aboriginal English (AAE), their traditional languages (e.g. Martu and Kija), SAE, as well as Kriol (an Australian creole) in some remote locations. We also found they adjusted their language choices according to the audience and content of their discussions and they utilised processes of translanguaging as part of these school interactions.

Club convergence in regional labor productivity: how do Australian states and territories compare to the US, UK, and Canadian subnational regions?

AbstractDeveloping strategies to enhance productivity growth requires identifying leading and lagging regions, industries, and growth drivers. However, there are limited cross-country studies using subnational data. Our study goes beyond the traditional country convergence approach and estimates labor productivity convergence using Philips and Sul’s club convergence approach and subnational data from 2004 to 2020. We aim to determine whether labor productivity growth rates in Australian states and territories are equal, converging, or divergent as compared to United States, United Kingdom, and Canadian subnational regions. The results show that five Australian jurisdictions, including Western Australia and New South Wales, are in the high labor productivity group (Club 1), while the remaining three i.e., Australian Capital Territory, Victoria, and Queensland, are in the moderate growth group (Club 2). We also used fixed effects models with least squares dummy variable estimators to identify the club’s characteristics. The results show that regions with a high proportion of employees in information and communications technology, energy, mining, and resources experienced higher labor productivity growth than those with a manufacturing sector. Human capital, innovation, and household disposable income were associated with high labor productivity, whereas high old-age dependency and children-to-women ratios were associated with lower growth. These results are consistent with the macroeconomic phenomenon that economic development leads to inequality and polarization in certain regions of a country. Nonetheless, the findings are useful for decision-makers and researchers to use in benchmarking and improving regional strategies by identifying regional peers and factors that influence convergence or divergence that can be improved. The results provide insightful findings for consideration by policymakers seeking to boost labor productivity or to bridge regional gaps in productivity.

Investigating environmental and geographical factors affecting iodine concentrations in Australian wheat (Triticum aestivum L.) grain

Iodine is an essential micronutrient for human nutrition, though it is found in relatively low concentrations in many important crop species. Wheat (Triticum aestivum L.) is a common staple crop worldwide, and as such could be an important source of dietary iodine due to its widespread consumption. However, little is known about iodine concentrations in wheat grain grown under rainfed field conditions, nor the impact of growing region or environment on these concentrations. Therefore, this paper had three objectives; (1) quantify the iodine concentration in a popular variety of wheat cultivated across the wheat belt of three Australian States (Western Australia, South Australia and Victoria) over two winter seasons (2) determine the influence of distance from the coast, rainfall, elevation, soil type and pH and grain yield on wheat grain iodine concentrations and (3) identify geographical areas where iodine concentrations of wheat grains are low enough that biofortification with iodine would be advantageous for human health outcomes. We sampled iodine concentrations of a single cv. Scepter at 125 sites from the winter season 2020 (65 sites) and 2021(60 sites), to investigate environmental and geographical effects on wheat grain iodine concentrations. Iodine concentrations were measured using triple quadrupole inductively coupled plasma mass spectrometer (ICP MS/MS). We found that the elevation and the region (State) of growing sites were the most significant predictors of iodine concentration, along with the interaction between rainfall and topsoil texture. However, very low concentrations of iodine (5–24 μg/kg) were detected in all samples tested, indicating that even wheat grown under advantageous environmental and geographic conditions in southern Australia would be unlikely to represent an important source of dietary iodine. This emphasises the need to consider biofortification strategies to improve iodine concentrations in Australian grown wheat to improve the dietary uptake of this essential micronutrient by human consumers.

Notification of acute rheumatic fever and rheumatic heart disease in hospitalised people in the Midwest region of Western Australia, 2012-2022: retrospective administrative data analysis.

Notification of acute rheumatic fever and rheumatic heart disease in hospitalised people in the Midwest region of Western Australia, 2012-2022: retrospective administrative data analysis.

Critical periods of maternal exposure to ambient fine particulate matter and the risks of stillbirth and spontaneous preterm birth in Western Australia

Few studies have investigated weekly or monthly exposure-lag-response association between fine particulate matter (PM2.5) and preterm birth, and there has been no known such study for stillbirth. We aimed to identify potential critical susceptible periods of the association between monthly PM2.5 exposure during pregnancy and stillbirth and spontaneous preterm birth (sPTB). A total of 414,771 singleton births, of which 0.5% and 3.9% were stillbirth and sPTB respectively, between 1st January 2000 and 31st December 2015 in Western Australia were linked to fine spatiotemporal monthly PM2.5 concentrations. Monthly distributed lag linear and non-linear Cox regressions were performed to investigate PM2.5 exposure during pregnancy and covariate-adjusted hazards of stillbirth and sPTB. The mean PM2.5 exposure during pregnancy was 8.1 μg/m3. Pregnancy PM2.5 exposure showed small dose-response associations with stillbirth and sPTB with critical susceptible periods spanning the 3rd–6th gestational months. Relative to 5 μg/m3, the strongest hazards of PM2.5 exposure were 1.04 (95% CI 0.99, 1.08) and 1.03 (95% CI 1.02, 1.05) during the 4th gestational month for stillbirth and sPTB, respectively. Monthly exposures at late pregnancy were associated with lower hazards. The average pregnancy exposure hazards were 1.08 (95% CI 0.88, 1.32) and 1.07 (95% CI 0.99, 1.15) per 5 μg/m3 increment for stillbirth and sPTB, respectively. The average entire pregnancy exposure showed potential attributable burden, synergistic interaction effects with biothermal stress, and comparatively higher hazards for female births and births to mothers who were Caucasian, < 35 years old, high SES, nulliparous, and smoked during pregnancy.