A cross-sectional analysis of associations between environmental indices and asthma in U.S. counties from 2003 to 2012

Emerging evidence for the impact of Electric Vehicle sales on childhood asthma: Can ZEV mandates help?

Growing epidemiological studies indicate a significant fraction of asthma cases can be attributed to traffic-related air pollution (TRAP). Zero emission vehicle (ZEV) mandates - one of the most forward-looking climate policies in the United States - aim to reduce TRAP by mandating automakers to sell a certain fraction of Electric Vehicles (EVs) annually; however, their public health benefits are largely unknown. We conduct the screening step of the health impact assessment (HIA) of real-world EV sales to estimate the impact of ZEV mandates in reducing childhood asthma. Using publicly available US state and national datasets, we isolate the burden of childhood asthma attributable to TRAP from 2013 to 2019 and examine the influence of EV and non-EV vehicle sales and fleets on asthma incidence and prevalence using a generalized linear mixed model. Our analyses indicate that new EV sales have reduced asthma, with one asthma case prevented for every 264 (95% CI: 113-401) new EVs on the road. The rise of new childhood asthma cases from new car sales can be prevented when non-EV sales are replaced with EV sales at an annual market share of 21.4% (7.1-41.6%). Extending our analysis to the entire vehicle fleet, we project that when EVs reach 53.0% (35.5%-76.9%), childhood asthma due to tailpipe emissions can be eradicated completely. Screening results conclude that ZEV mandates implemented over the past decade are already exhibiting measurable public health benefits, suggesting that a broader adoption could significantly reduce the asthma burden, thus we recommend a full HIA for ZEV mandates to fully assess their potential.

Mediation of the JNC/ILC2 pathway in DBP-exacerbated allergic asthma: A molecular toxicological study on neuroimmune positive feedback mechanism

BACKGROUND

Dibutyl phthalate (DBP), a commonly used plasticizer, has been found to be strongly linked to a consistently high prevalence of allergic diseases, particularly allergic asthma. Previous animal experiments have demonstrated that exposure to DBP can worsen asthma by triggering the production of calcitonin gene-related peptide (CGRP), a neuropeptide in the lung tissue. However, the precise neuroimmune mechanism and pathophysiology of DBP-exacerbated allergic asthma with the assistance of CGRP remain unclear.

OBJECTIVE

The present study was to investigate the potential pathophysiological mechanism in DBP-exacerbated asthma from the perspective of neural-immune interactions.

METHODS AND RESULTS

C57BL/6 mice were orally exposed to different concentrations (0.4, 4, 40 mg/kg) of DBP for 28 days. They were then sensitized with OVA and nebulized with OVA for 7 consecutive excitations. To investigate whether DBP exacerbates allergic asthma in OVA induced mice, we analyzed airway hyperresponsiveness and lung histopathology. To investigate the activation of JNC and TRPV1 neurons and the release of CGRP by JNC cells, we measured the levels of TRPV1 channels, calcium inward flow, and downstream neuropeptide CGRP. Results showed that TRPV1 expression, inward calcium flux, and CGRP levels were significantly elevated in the lung tissues of the 40DBP + OVA group, suggesting the release of CGRP by JNC cells. To counteract the detrimental effects of DBP mediated by CGRP, we employed olcegepant (also known as BIBN-4096), a CGRP receptor specific antagonist. Results revealed that 40DBP + OVA + olcegepant led to notable decreases in TRPV1, calcium inward flow, and CGRP expression in lung tissues compare with 40DBP + OVA, further supporting the efficacy of olcegepant. Additionally, we also conducted ILC2 flow sorting and observed that neuropeptide CGRP-activated ILC2 cells have a crucial role as key effector cells in DBP-induced neuroimmune positive feedback regulation. Finally, we examined the protein expression of CGRP, GATA3 and P-GATA3, and found that significant upregulations of CGRP and P-GATA3 in the 40DBP + OVA group, suggest that GATA3 acted as a key regulator of CGRP-activated ILC2.

CONCLUSION

The aforementioned studies indicate that exposure to DBP can exacerbate allergic asthma, leading to airway inflammation. This exacerbation occurs through the activation of TRPV1 in JNC, resulting in the release of CGRP. The excessive release of CGRP further promotes the release of Th2 cytokines by inducing the activation of ILC2 through GATA phosphorylation. Consequently, this process contributes to the development of airway inflammation and allergic asthma. The increased production of Th2 cytokines also triggers the production of IgE, which interacts with FcεRI on JNC neurons, thereby mediating neuro-immune positive feedback regulation.