Air pollution, methane super-emitters, and oil and gas wells in Northern California: the relationship with migraine headache prevalence and exacerbation

The human health effects of unconventional oil and gas development (UOGD): A scoping review of epidemiologic studies

OBJECTIVE

Unconventional oil and gas development (UOGD, sometimes termed "fracking" or "hydraulic fracturing") is an industrial process to extract methane gas and/or oil deposits. Many chemicals used in UOGD have known adverse human health effects. Canada is a major producer of UOGD-derived gas with wells frequently located in and around rural and Indigenous communities. Our objective was to conduct a scoping review to identify the extent of research evidence assessing UOGD exposure-related health impacts, with an additional focus on Canadian studies.

METHODS

We included English- or French-language peer-reviewed epidemiologic studies (January 2000-December 2022) which measured exposure to UOGD chemicals directly or by proxy, and where health outcomes were plausibly caused by UOGD-related chemical exposure. Results synthesis was descriptive with results ordered by outcome and hierarchy of methodological approach.

SYNTHESIS

We identified 52 studies from nine jurisdictions. Only two were set in Canada. A majority (n = 27) used retrospective cohort and case-control designs. Almost half (n = 24) focused on birth outcomes, with a majority (n = 22) reporting one or more significant adverse associations of UOGD exposure with: low birthweight; small for gestational age; preterm birth; and one or more birth defects. Other studies identified adverse impacts including asthma (n = 7), respiratory (n = 13), cardiovascular (n = 6), childhood acute lymphocytic leukemia (n = 2), and all-cause mortality (n = 4).

CONCLUSION

There is a growing body of research, across different jurisdictions, reporting associations of UOGD with adverse health outcomes. Despite the rapid growth of UOGD, which is often located in remote, rural, and Indigenous communities, Canadian research on its effects on human health is remarkably sparse. There is a pressing need for additional evidence.

A prospective exploration of the urban exposome in relation to headache in the Dutch population-based Occupational and environmental health cohort study (AMIGO)

OBJECTIVE

Headache is one of the most prevalent and disabling health conditions globally. We prospectively explored the urban exposome in relation to weekly occurrence of headache episodes using data from the Dutch population-based Occupational and Environmental Health Cohort Study (AMIGO).

MATERIAL AND METHODS

Participants (N = 7,339) completed baseline and follow-up questionnaires in 2011 and 2015, reporting headache frequency. Information on the urban exposome covered 80 exposures across 10 domains, such as air pollution, electromagnetic fields, and lifestyle and socio-demographic characteristics. We first identified all relevant exposures using the Boruta algorithm and then, for each exposure separately, we estimated the average treatment effect (ATE) and related standard error (SE) by training causal forests adjusted for age, depression diagnosis, painkiller use, general health indicator, sleep disturbance index and weekly occurrence of headache episodes at baseline.

RESULTS

Occurrence of weekly headache was 12.5 % at baseline and 11.1 % at follow-up. Boruta selected five air pollutants (NO2, NOX, PM10, silicon in PM10, iron in PM2.5) and one urban temperature measure (heat island effect) as factors contributing to the occurrence of weekly headache episodes at follow-up. The estimated causal effect of each exposure on weekly headache indicated positive associations. NO2 showed the largest effect (ATE = 0.007 per interquartile range (IQR) increase; SE = 0.004), followed by PM10 (ATE = 0.006 per IQR increase; SE = 0.004), heat island effect (ATE = 0.006 per one-degree Celsius increase; SE = 0.007), NOx (ATE = 0.004 per IQR increase; SE = 0.004), iron in PM2.5 (ATE = 0.003 per IQR increase; SE = 0.004), and silicon in PM10 (ATE = 0.003 per IQR increase; SE = 0.004).

CONCLUSION

Our results suggested that exposure to air pollution and heat island effects contributed to the reporting of weekly headache episodes in the study population.

Long-term exposure to air pollutants and new-onset migraine: A large prospective cohort study

BACKGROUNDS

Short-term exposure to air pollutants increases the risk of migraine, but the long-term impacts of exposure to multiple pollutants on migraine have not been established. The aim of this large prospective cohort study was to explore these links.

METHODS

A total of 458,664 participants who were free of migraine at baseline from the UK Biobank were studied. Cox proportional hazards models were used to estimate the risk of new-onset migraine from combined long-term exposure to four pollutants, quantified as an air pollution score using principal component analysis.

RESULTS

During a median (IQR) follow-up of 12.5 (11.8, 13.2) years, a total of 5417 new-onset migraine cases were documented. Long-term exposure to multiple air pollutants was associated with an increased risk of new-onset migraine, as indicated by an increased in the SDs of PM2.5 (hazard ratio (HR): 1.04, 95% CI: 1.01-1.06, P = 0.009), PM10 (HR: 1.07, 95% CI: 1.04-1.10, P < 0.001), NO2 (HR: 1.10, 95% CI: 1.07-1.13, P < 0.001) and NOx (HR: 1.04, 95% CI: 1.01-1.07, P = 0.005) in the main model. The air pollution score showed a doseresponse association with an increased risk of new-onset migraine. Similarly, compared with those of the lowest tertile, the HRs (95% CI) of new-onset migraine were 1.11 (95% CI: 1.04-1.19, P = 0.002) and 1.17 (95% CI: 1.09-1.26, P < 0.001) in tertiles 2 and 3, respectively, according to the main model (P trend < 0.001).

CONCLUSION

Long-term individual and joint exposure to multiple air pollutants is associated with an increased risk of new-onset migraine.

Migraine and air pollution: A systematic review

OBJECTIVE

To systematically synthesize evidence from a broad range of studies on the association between air pollution and migraine.

BACKGROUND

Air pollution is a ubiquitous exposure that may trigger migraine attacks. There has been no systematic review of this possible association.

METHODS

We searched for empirical studies assessing outdoor air pollution and any quantified migraine outcomes. We included short- and long-term studies with quantified air pollution exposures. We excluded studies of indoor air pollution, perfume, or tobacco smoke. We assessed the risk of bias with the World Health Organization's bias assessment instrument for air quality guidelines.

RESULTS

The final review included 12 studies with over 4,000,000 participants. Designs included case-crossover, case-control, time series, and non-randomized pre-post intervention. Outcomes included migraine-related diagnoses, diary records, medical visits, and prescriptions. Rather than pooling the wide variety of exposures and outcomes into a meta-analysis, we tabulated the results. Point estimates above 1.00 reflected associations of increased risk. In single-pollutant models, the percent of point estimates above 1.00 were carbon monoxide 5/5 (100%), nitrogen dioxide 10/13 (78%), ozone 7/8 (88%), PM2.5 13/15 (87%), PM10 2/2 (100%), black carbon 0/1 (0%), methane 4/6 (75%), sulfur dioxide 3/5 (60%), industrial toxic waste 1/1 (100%), and proximity to oil and gas wells 6/13 (46%). In two-pollutant models, 16/17 (94%) of associations with nitrogen dioxide were above 1.00; however, more than 75% of the confidence intervals included the null value. Most studies had low to moderate risks of bias. Where differences were observed, stronger quality articles generally reported weaker associations.

CONCLUSIONS

Balancing the generally strong methodologies with the small number of studies, point estimates were mainly above 1.00 for associations of carbon monoxide, nitrogen dioxide, ozone, and particulate matter with migraine. These results were most consistent for nitrogen dioxide.

Acute effects of ambient air pollution on daily neurology clinic visits for vertigo: a time-series study in Wuhan, China

This study aimed to disclose the relationship between ambient air pollution and neurology clinic visits (NCVs) for vertigo. A time-series study was conducted to examine relationships between six different criteria air pollutants (SO₂, NO₂, PM_2.5, PM₁₀, CO, and O₃) and daily NCVs for vertigo in Wuhan, China, from January 1st, 2017 to November 30th, 2019. Stratified analyses were computed according to gender, age, and season. A total of 14,749 records of NCVs for vertigo were enrolled in this study. Data showed that the increase in daily NCVs for vertigo corresponding to 10 μg/m³ increase of respective pollutants are: SO₂ (- 7.60%; 95% CI: - 14.25 to - 0.44%), NO₂ (3.14%; 95% CI: 0.23 to 6.13%), PM_2.5 (0.53%; 95% CI: - 0.66 to 1.74%), PM₁₀ (1.32%; 95% CI: - 0.36 to 3.06%), CO (0.00%; 95% CI: - 0.12 to 0.13%), and O₃ (0.90%; 95% CI: - 0.01% to 1.83%). Males were more susceptible to acute exposure to SO₂ and NO₂, compared to females (SO₂: - 11.91% vs. - 4.16%; NO₂: 3.95% vs. 2.92%), whereas the acute effect of O₃ exposure was more significantly obvious in females than males (0.94% vs. 0.87%). Moreover, correlations between daily NCVs for vertigo and acute exposure to SO₂, NO₂, and O₃ were all stronger in individuals under 50 years old (SO₂: - 12.75% vs. - 4.41%; NO₂: 4.55% vs. 2.75%; O₃: 1.27% vs. 0.70%). Short-term exposure to PM_2.5 was more significantly associated with daily NCVs for vertigo in cool seasons (1.62% vs. - 0.68%), while the correlation between CO exposure and daily NCVs for vertigo was stronger in warm seasons (0.21% vs. - 0.03%). Our study demonstrated acute exposure to ambient NO₂ and O₃ positively associated with daily NCVs for vertigo. Acute effects of air pollution on daily NCVs for vertigo varied according to gender, age, and season.

Association of obesity with headache among US children and adolescents: Evidence from NHANES 1999-2004

Background

Children and adolescents increasingly commonly suffer from obesity and headache. It has been confirmed that there is an association between obesity and headache in adults; however, evidence of such an association in paediatric populations is still controversial. Therefore, this study examined the relationship between obesity and headache among children and adolescents in the US.

Methods

The cross-sectional data of 3948 participants were obtained from the National Health and Nutrition Examination Survey 1999-2004. Weighted logistic regression models were applied to investigate the association between obesity and headache. Subgroup analysis stratified by sex and age was performed to explore the potential difference in the association of paediatric obesity with headache. The performance of paediatric obesity on headache was assessed by receiver operating characteristic (ROC) curve.

Results

The present study involved 3948 participants, of whom 713 (18.1%) had headache. Compared to those without headache, participants with headache tended to be girls and adolescents, have less calcium intake, and have higher levels of body mass index (BMI), C-reactive protein (CRP), serum ferritin and triglycerides (TGs) (all P < 0.05). After fully adjusting for potential confounders, the ORs with 95% CIs for headache were 1.03 (0.58-1.54) and 1.25 (0.68-2.30) for overweight and obese participants in comparison with normal-weight controls, respectively, implying no association of paediatric obesity with headache independent of other potential confounding factors. In addition, although higher odds of headache were noted in girls and adolescents (aged 10-17 years), no statistically significant difference was found across any subgroups. The area under the ROC (AUC) of paediatric obesity on headache was 0.634.

Conclusions

In summary, our study indicated that obesity is not associated with headache among US children and adolescents. Further prospective studies with larger sample size are needed to validate our findings.

Association Between Asthma and Migraine: A Systematic Review and Meta-Analysis of Observational Studies

Objectives: The purpose of this study was to determine the association between asthma and migraine and assess the risk for migraine in patients with asthma.

Methods: We systematically searched the Cochrane Library, PubMed, Medical Literature Analysis and Retrieval System Online (MEDLINE), and Excerpta Medica dataBASE (EMBASE) databases from inception to September 26, 2021, for indexed observational studies that examined either the odds or risk of migraine in subjects with asthma. The qualities of the included studies were evaluated using the Newcastle–Ottawa Scale. A random-effects meta-analysis was performed to calculate the odds ratio for case-control and cross-sectional studies and the risk ratio for cohort studies.

Results: Seven observational studies (four cross-sectional and three cohort studies) with a total of 549,534 study subjects were included in this systematic review and meta-analysis and selected for data extraction. Four articles were considered to be of moderate quality; other studies were considered to be of high quality. Asthma was associated with increased odds (OR, 1.85; 95%CI, 1.39–2.45) and risk of migraine (RR, 1.70; 95%CI, 1.52–1.90).

Conclusions: The available evidence that supports the existence of an association between asthma and migraine is limited. Clinicians should be aware that patients with asthma show both increased prevalence and incidence of migraine. Further studies are warranted to further clarify the relationship between asthma and migraine.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=185881, identifier: CRD42020185881.