Journal Article Annotations
2022, 2nd Quarter

Climate Change

Annotations by Mary Burke, MD
July, 2022

Associations of short-term exposure to air pollution and increased ambient temperature with psychiatric hospital admissions in older adults in the USA: a case–crossover study.
Pollution and Health: a Progress Update..

PUBLICATION #1 — Climate Change

Associations of short-term exposure to air pollution and increased ambient temperature with psychiatric hospital admissions in older adults in the USA: a case–crossover study.

Xinye Qiu, Mahdieh Danesh-Yazdi, Yaguang Wei, Qian Di, Allan Just, Antonella Zanobetti, Marc Weisskopf, Francesca Dominici, Joel Schwartz

Abstract: Lancet Planet Health. 2022 Apr;6(4):e331-e341. doi: 10.1016/S2542-5196(22)00017-1.

Background
Little is known about the associations between ambient environmental exposures and the risk of acute episodes of psychiatric disorders. We aimed to estimate the link between short-term exposure to atmospheric pollutants, temperature, and acute psychiatric hospital admissions in adults aged 65 years and older in the USA.

Methods
For this study, we included all people (aged ≥65 years) enrolled in the Medicare programme in the USA who had an emergency or urgent hospital admission for a psychiatric disorder recorded between Jan 31, 2000, and Dec 31, 2016. We applied a case-crossover design to study the associations between short-term exposure to air pollution (fine particulate matter [PM_2·5], ozone, and nitrogen dioxide [NO₂]), ambient temperature, and the risk of acute hospital admissions for depression, schizophrenia, and bipolar disorder in this population. The percentage change in the risk of hospital admission and annual absolute risk differences were estimated.

Findings
For each 5°C increase in short-term exposure to cold season temperature, the relative risk of acute hospital admission increased by 3·66% (95% CI 3·06–4·26) for depression, by 3·03% (2·04–4·02) for schizophrenia, and by 3·52% (2·38–4·68) for bipolar disorder in the US Medicare population. Increased short-term exposure to PM_2·5 and NO₂ was also associated with a significant increase in the risk of acute hospital admissions for psychiatric disorders. Each 5 μg/m³ increase in PM_2·5 was associated with an increase in hospital admission rates of 0·62% (95% CI 0·23–1·02) for depression, 0·77% (0·11–1·44) for schizophrenia, and 1·19% (0·49–1·90) for bipolar disorder; each 5 parts per billion (ppb) increase in NO₂, meanwhile, was linked to an increase in hospital admission rates of 0·35% (95% CI 0·03–0·66) for depression and 0·64% (0·20–1·08) for schizophrenia. No such associations were found with warm season temperature.

Interpretation
In the US Medicare population, short-term exposure to elevated concentrations of PM_2·5 and NO₂ and cold season ambient temperature were significantly associated with an increased risk of hospital admissions for psychiatric disorders. Considering the increasing burden of psychiatric disorders in the US population, these findings suggest that intervening on air pollution and ambient temperature levels through stricter environmental regulations or climate mitigation could help ease the psychiatric health-care burden.

Annotation

The finding:
The relationship between heat waves and increased psychiatric hospitalizations is well-documented. This study amplifies that finding and highlights the vulnerability of older individuals, including in rural areas (who typically are understudied in climate-crisis research). Most of us tend to minimize the gravity of unusual spells of mild weather in the winter. This conclusively shows that we all need to be alert to the higher risk this poses to our patients, not just acutely but also chronically, as we continue to see temperatures rise. The study also points out how multiple pollutants, not just PM2.5, impose a real risk to those with severe mental illness.

Strength and weaknesses:
This study enrolled all individuals enrolled in Medicare in the USA with a primary psychiatric disorder, and all psychiatric admissions due to depression, schizophrenia, or bipolar disorder over 16 years. Levels of heat have only increased since 2016 when the study closed. The study design is rigorous, with a case-crossover design in which persons were matched to themselves on control days (when they were not admitted).

The authors note that they could not account for all potential confounders, and the study only describes correlative data.

Relevance:
The climate and environmental crises are the biggest health issues that we will face in our professional career. Research into mechanisms of environmental/ climate toxicities and mental illness are have also clarified mechanisms of illess for psychiatric disease more generally (such as the role of inflammation or perturbations in glucocorticoid and serotonergic activity). This article reinforces C-L psychiatrists’ role as clinicians who should anticipate worsened outcomes as the environment degrades; patient educators on the risks of heat and pollution; and professional educators who teach that climate and environment, like childhood stress or substance abuse, impact brain health and therefore psychiatric health. More research is needed to inform how typical practice (such as prescribing) may be affected by climate change and how specific interventions may mitigate these adverse outcomes.

PUBLICATION #2 — Climate Change

Pollution and Health: a Progress Update.

Richard Fuller, Philip J Landrigan, Kalpana Balakrishnan, Glynda Bathan, Stephan Bose-O’Reilly, Michael Brauer, Jack Caravanos, Tom Chiles, Aaron Cohen, Lilian Corra, Maureen Cropper, Greg Ferraro, Jill Hanna, David Hanrahan, Howard Hu, David Hunter, Gloria Janata, Rachael Kupka, Bruce Lanphear, Maureen Lichtveld, Keith Martin, Adetoun Mustapha, Ernesto Sanchez-Triana, Karti Sandilya, Laura Schaefli, Joseph Shaw, Jessica Seddon, William Suk, Martha María Téllez-Rojo, Chonghuai

Abstract: Lancet Planet Health. 2022 Jun;6(6):e535-e547. doi: 10.1016/S2542-5196(22)00090-0. Epub 2022 May 18.

The Lancet Commission on pollution and health reported that pollution was responsible for 9 million premature deaths in 2015, making it the world’s largest environmental risk factor for disease and premature death. We have now updated this estimate using data from the Global Burden of Diseases, Injuriaes, and Risk Factors Study 2019. We find that pollution remains responsible for approximately 9 million deaths per year, corresponding to one in six deaths worldwide. Reductions have occurred in the number of deaths attributable to the types of pollution associated with extreme poverty. However, these reductions in deaths from household air pollution and water pollution are offset by increased deaths attributable to ambient air pollution and toxic chemical pollution (ie, lead). Deaths from these modern pollution risk factors, which are the unintended consequence of industrialisation and urbanisation, have risen by 7% since 2015 and by over 66% since 2000. Despite ongoing efforts by UN agencies, committed groups, committed individuals, and some national governments (mostly in high-income countries), little real progress against pollution can be identified overall, particularly in the low-income and middle-income countries, where pollution is most severe. Urgent attention is needed to control pollution and prevent pollution-related disease, with an emphasis on air pollution and lead poisoning, and a stronger focus on hazardous chemical pollution. Pollution, climate change, and biodiversity loss are closely linked. Successful control of these conjoined threats requires a globally supported, formal science-policy interface to inform intervention, influence research, and guide funding. Pollution has typically been viewed as a local issue to be addressed through subnational and national regulation or, occasionally, using regional policy in higher-income countries. Now, however, it is increasingly clear that pollution is a planetary threat, and that its drivers, its dispersion, and its effects on health transcend local boundaries and demand a global response. Global action on all major modern pollutants is needed. Global efforts can synergise with other global environmental policy programmes, especially as a large-scale, rapid transition away from all fossil fuels to clean, renewable energy is an effective strategy for preventing pollution while also slowing down climate change, and thus achieves a double benefit for planetary health.

Annotation

The finding:
Toxic pollution continues to be a major threat to human health. This study estimated that in 2019, 9 million deaths were due to pollution—around 16% of the global total. As with all environmental impacts, morbidity and mortality are felt less in prosperous nations or by wealthier citizens, highlighting how environmental deterioration is a multiplier of determinants of illness. In addition, the study broke down the impact of specific pollutants including lead: “More than 800 million children are estimated to have blood lead concentrations that exceed 5·0 μg/dL…The implications of this finding for children’s intellectual impairment are staggering. Other neurotoxins are abundant and pose developmental threats to children and pregnancies.”

Strength and weaknesses:
This update of a 2015 global survey provides evidence that governments need to act decisively to limit industrial sources of contamination. The article concludes with recommendations for governments and other larger institutions but also emphasized the importance of monitoring toxic exposures—and especially lead—in pregnant women and children.

Relevance:
The authors point out that “The impact of pollution on health remains much greater than that of war, terrorism, malaria, HIV, tuberculosis, drugs, and alcohol, and the number of deaths caused by pollution are on par with those caused by smoking.“ While people can become numb and disconnected in the face of overwhelmingly bad news, in fact, C-L psychiatrists can play an active role in addressing these adverse impacts for patients. Psychiatrists can serve as educators, advocates, and clinicians; at a minimum, we as clinicians can monitor the effect pollutants and heat have on our patients, in particular our pediatric and pregnant patients.