Association between sugar cane burning and acute respiratory illness on the island of Maui

Asthma medication usage after environmental exposure to wildfire smoke: A systematic review

Asthma is a chronic respiratory condition exacerbated by exposure to particulate air pollution. Smoke from landscape fires has been associated with increased mortality, asthma-related admissions to emergency and other hospital departments, and uptake in primary care services. With climate change and more frequent landscape fires, healthcare systems must prepare for disaster, including surges in asthma medication demand. Past reviews have not resolved the direction and magnitude of the association between PM2.5 exposure during landscape fires and asthma medication use. The aim of this review was to investigate the relationship between exposure to landscape fire smoke and the use of asthma medications. We conducted a systematic review of PubMed, Scopus, and Web of Science, identifying peer-reviewed articles that examined asthma medication usage following environmental exposure to landscape fire smoke. After a full-text review, we identified twelve articles, three from Canada, three from the USA and six from Australia, with five being retrospective cohort studies. Despite differences in study design, outcome and exposure assessment, the included studies reported a consistent increase in asthma medication use after exposure to wildfires. There is consistent evidence that exposure to wildfire smoke is associated with an increase in the use of reliever medications, particularly salbutamol. Increases in other asthma management medications were also consistently identified. Increases in demand for asthma medications after exposure to wildfire smoke highlight the urgent need to address the growing frequency and intensity of wildfires driven by climate change.

Occupational exposure to respirable and inhalable dust and its components in a Nicaraguan sugarcane plantation

OBJECTIVE

To assess personal exposure to respirable and inhalable dust and its components endotoxin, black carbon and crystalline silica among sugarcane workers in Nicaragua.

METHODS

Individual exposures to respirable (measurements=98) and inhalable (measurements=36) dust were collected in January and March 2020, with the month of March generally being hotter and less humid. Respirable dust and its components black carbon and crystalline silica, as well as inhalable dust and its component endotoxin, were personally measured. Linear mixed models were used to identify the determinants of occupational dust exposure considering different job tasks and meteorological conditions.

RESULTS

Respirable dust and black carbon concentrations were higher in March among burned cane cutters compared with the other job groups (respirable dust geometric mean (GM)=1.9 mg m-3; black carbon GM=13.7 µg m-3), with considerably lower levels in January (respirable dust GM=0.2 mg m-3; black carbon GM=3.4 µg m-3). Almost all respirable crystalline silica measurements were below the limit of detection, except for four measurements, which ranged from 8 µg m-³ to 15 µg m-³. Seed cutters (GM=3.1 mg m-3) and weeders (GM=2.5 mg m-3) had the highest exposure to inhalable dust, while endotoxin concentrations were higher among seed cutters (GM=100 EU m-3) and burned cane cutters (GM=63 EU m-3) than the other work groups.

CONCLUSIONS

Overall, exposure levels to the assessed agents varied across work groups, with higher levels observed among burned cane and seed cutters.

Health burden of sugarcane burning on agricultural workers and nearby communities

Sugarcane is the most widely cultivated crop in the world, with equatorial developing nations performing most of this agriculture. Burning sugarcane is a common practice to facilitate harvest, producing extremely high volumes of respirable particulate matter in the process. These emissions are known to have deleterious effects on agricultural workers and nearby communities, but the extent of this exposure and potential toxicity remain poorly characterized. As the epidemicof chronic kidney disease of an unknown etiology (CKDu) and its associated mortality continue to increase along with respiratory distress, there is an urgent need to investigate the causes, determine viable interventions to mitigate disease andimprove outcomes for groups experiencing disproportionate impact. The goal of this review is to establish the state of available literature, summarize what is known in terms of human health risk, and provide recommendations for what areas should be prioritized in research.

Agricultural burning in Imperial Valley, California and respiratory symptoms in children: A cross-sectional, repeated measures analysis

Burning of agricultural fields is an understudied source of air pollution in rural communities in the United States. Smoke from agricultural burning contains air toxics that adversely impact respiratory health. Imperial County in southeastern California is a highly productive agricultural valley that heavily employs agricultural burning to clear post-harvest crop remnants. We related individual-level exposure to agricultural burns to parent-reported respiratory symptoms in children. We leveraged the Children's Assessing Imperial Valley Respiratory Health and the Environment (AIRE) cohort of 735 predominantly Hispanic low-income elementary school students in Imperial County. Parents reported children's respiratory health symptoms and family demographic characteristics in questionnaires collected at enrollment and in annual follow-up assessments from 2017 to 2019. Permitted agricultural burns in Imperial County from 2016 to 2019 were spatially linked to children's geocoded residential addresses. We used generalized estimating equations to evaluate prevalence differences (PDs) in respiratory symptoms with increasing exposure to agricultural burning within 3 km in the 12 months prior to each assessment. Nearly half of children (346, 49 %) lived within 3 km of at least one agricultural burn in the year prior to study enrollment. In adjusted models, each additional day of agricultural burning in the prior year was associated with a one percentage point higher prevalence of wheezing (PD 1.1 %; 95 % CI 0.2 %, 2.0 %) and higher bronchitic symptoms (PD 1.0 %; 95 % CI -0.2 %, 2.1 %). Children exposed to four or more days of burning had an absolute increased prevalence of wheezing and bronchitic symptoms of 5.9 % (95 % CI -0.3 %, 12 %) and 5.6 % (95 % CI -1.8 %, 13 %), respectively, compared to no burn exposure. Associations with wheezing were stronger among children with asthma (PD 14 %; 95 % CI -1.4 %, 29 %). To our knowledge, this is the first U.S. study of agricultural burning and children's respiratory health. This work suggests that reducing agricultural burning could improve children's respiratory health.

[Burning of sugarcane biomass and hospitalizations of children and older adults for respiratory problems in Pernambuco State, Brazil]

This study aimed to analyze the relationship between hospitalizations for respiratory problems and the regular burning of sugarcane in Pernambuco State, Brazil. This is an ecological time series study corresponding to the period from 2008 to 2018. The rates of hospitalizations for respiratory diseases in children aged under 5 years and in adults older than 60 years in sugarcane-producing and non-producing municipalities were compared using nonparametric Mann-Whitney statistical analysis. Together, we observed the monthly distribution of the hot spots occurrences in the case and control municipalities and applied Pearson's correlation to analyze the association between both variables. For both age groups, hospitalization rates are higher in sugarcane-producing municipalities, with a statistically significant difference p < 0.005. The rate of hospitalization in older adults is 28% higher in the case municipalities, and is even higher in children aged under 5 years whose ratio of the medians is 40%. However, the seasonal behavior of hospitalizations for respiratory diseases differs from that observed in the monthly distribution of hot spots, without statistically significant correlation. These findings suggest a possible association with chronic exposure to particulates emitted by biomass burning, compromising the health of vulnerable groups, and endorse the need to replace fires in the monoculture of sugarcane and to structure public policies to protect human and environmental health.

Impacts of Sugarcane Fires on Air Quality and Public Health in South Florida

BACKGROUND

Preharvest burning of sugarcane is a common agricultural practice in Florida, which produces fine particulate matter [particulate matter (PM) with aerodynamic diameter ≤2.5μm (PM2.5)] that is associated with higher mortality.

OBJECTIVES

We estimated premature mortality associated with exposure to PM2.5 from sugarcane burning in people age 25 y and above for 20 counties in South Florida.

METHODS

We combined information from an atmospheric dispersion model, satellites, and surface measurements to quantify PM2.5 concentrations in South Florida and the fraction of PM2.5 from sugarcane fires. From these concentrations, estimated mortalities attributable to PM2.5 from sugarcane fires were calculated by census tract using health impact functions derived from literature for six causes of death linked to PM2.5. Confidence intervals (CI) are provided based on Monte Carlo simulations that propagate uncertainty in the emissions, dispersion model, health impact functions, and demographic data.

RESULTS

Sugarcane fires emitted an amount of primary PM2.5 similar to that of motor vehicles in Florida. PM2.5 from sugarcane fires is estimated to contribute to mortality rates within the Florida Sugarcane Growing Region (SGR) by 0.4 death per 100,000 people per year (95% CI: 0.3, 1.6 per 100,000). These estimates imply 2.5 deaths per year across South Florida were associated with PM2.5 from sugarcane fires (95% CI: 1.2, 6.1), with 0.16 in the SGR (95% CI: 0.09, 0.6) and 0.72 in Palm Beach County (95% CI: 0.17, 2.2).

DISCUSSION

PM2.5 from sugarcane fires was estimated to contribute to mortality risk across South Florida, particularly in the SGR. This is consistent with prior studies that documented impacts of sugarcane fire on air quality but did not quantify mortality. Additional health impacts of sugarcane fires, which were not quantified here, include exacerbating nonfatal health conditions such as asthma and cardiovascular problems. Harvesting sugarcane without field burning would likely reduce PM2.5 and health burdens in this region. https://doi.org/10.1289/EHP9957.

Short-term health effects from outdoor exposure to biomass burning emissions: A review

Biomass burning (BB) including forest, bush, prescribed fires, agricultural fires, residential wood combustion, and power generation has long been known to affect climate, air quality and human health. With this work we supply a systematic review on the health effects of BB emissions in the framework of the WHO activities on air pollution. We performed a literature search of online databases (PubMed, ISI, and Scopus) from year 1980 up to 2020. A total of 81 papers were considered as relevant for mortality and morbidity effects. High risk of bias was related with poor estimation of BB exposure and lack of adjustment for important confounders. PM10 and PM2.5 concentrations originating from BB were associated with all-cause mortality: the meta-analytical estimate was equal to 1.31% (95% CI 0.71, 1.71) and 1.92% (95% CI -1.19, 5.03) increased mortality per each 10 μg m^-3 increase of PM10 and PM2.5, respectively. Regarding cardiovascular mortality 8 studies reported quantitative estimates. For smoky days and for each 10 μg m^-3 increase in PM2.5 concentrations, the risk of cardiovascular mortality increased by 4.45% (95% CI 0.96, 7.95) and by 3.30% (95% CI -1.97, 8.57), respectively. Fourteen studies evaluated whether respiratory morbidity was adversely related to PM2.5 (9 studies) or PM10 (5 studies) originating from BB. All found positive associations. The pooled effect estimates were 4.10% (95% CI 2.86, 5.34) and 4.83% (95% CI 0.06, 9.60) increased risk of total respiratory admissions/emergency visits, per 10 μg m^-3 increases in PM2.5 and PM10, respectively. Regarding cardiovascular morbidity, sixteen studies evaluated whether this was adversely related to PM2.5 (10 studies) or PM10 (6 studies) originating from BB. They found both positive and negative results, with summary estimates equal to 3.68% (95% CI -1.73, 9.09) and 0.93% (95% CI -0.18, 2.05) increased risk of total cardiovascular admissions/emergency visits, per 10 μg m^-3 increases in PM2.5 and PM10, respectively. To conclude, a significant number of studies indicate that BB exposure is associated with all-cause and cardiovascular mortality and respiratory morbidity.

Meteorological and Air Quality Modeling for Hawaii, Puerto Rico, and Virgin Islands

A photochemical model platform for Hawaii, Puerto Rico, and Virgin Islands predicting O₃, PM_2.5, and regional haze would be useful to support assessments relevant for the National Ambient Air Quality Standards (NAAQS), Regional Haze Rule, and the Prevention of Significant Deterioration (PSD) program. These areas have not traditionally been modeled with photochemical transport models, but a reasonable representation of meteorology, emissions (natural and anthropogenic), chemistry, and deposition could support air quality management decisions in these areas. Here, a prognostic meteorological model (Weather Research and Forecasting) and photochemical transport (Community Multiscale Air Quality) model were applied for the entire year of 2016 at 27, 9, and 3 km grid resolution for areas covering the Hawaiian Islands and Puerto Rico/Virgin Islands. Model predictions were compared against surface and upper air meteorological and chemical measurements available in both areas. The vertical gradient of temperature, humidity, and winds in the troposphere was well represented. Surface layer meteorological model performance was spatially variable, but temperature tended to be underestimated in Hawaii. Chemically speciated daily average PM_2.5 was generally well characterized by the modeling system at urban and rural monitors in Hawaii and Puerto Rico/Virgin Islands. Model performance was notably impacted by the wildfire emission methodology. Model performance was mixed for hourly SO₂, NO₂, PM_2.5, and CO and was often related to how well local emissions sources were characterized. SO₂ predictions were much lower than measurements at monitors near active volcanos on Hawaii, which was expected since volcanic emissions were not included in these model simulations. Further research is needed to assess emission inventory representation of these areas and how microscale meteorology influenced by the complex land-water and terrain interfaces impacts higher time resolution performance.

Crop burning and the prevalence of asthma and COPD emergency department treatments in a rural Arkansas county

OBJECTIVE

To evaluate the impact of crop burning on the prevalence of asthma and COPD emergency department (ED) treatments in a rural Arkansas county.

METHODS

Administrative datasets listing ED treatments for asthma and COPD obtained from the Arkansas Hospital Discharge Dataset System for the calendar years 2014-2016 were used in this semi-ecological study. Primary diagnosis codes (ICD-9: 490-496 and ICD-10: J40-J47) were used to identify patients who were diagnosed with asthma and COPD. Patients with a reported county of residence in Craighead County were determined as case county residents and those in Sebastian County were control county residents. Month of visit was used to determine seasonal variation. PM 2.5 air quality data were obtained from the EPA AQS Data Mart.

RESULTS

Between 2014 through 2016, there were a combined total of 2,536 ED treatments due to asthma and 8,530 due to COPD in Craighead and Sebastian counties. The odds of being treated in the ED during the fall months for asthma and COPD are associated with a 20.9% increase and 16.9% increase respectively in Craighead County as compared to Sebastian Country after adjusting for potential confounders (p = 0.04, p = 0.003). PM 2.5 concentrations were higher in Craighead County than Sebastian County during the fall season (p = 0.005).

CONCLUSION

Fall ED treatments for asthma and COPD were higher in Craighead County, Arkansas compared to Sebastian County, Arkansas for the years 2014-2016. PM 2.5 levels were also higher in Craighead County in the fall during these years. These differences may be attributable to crop burning.​.

Occupational effect of sugarcane biomass burning on the conjunctival mucin profile of harvest workers and residents of an adjacent town - A Brazilian panel study

Pre-harvest burning of sugarcane fields produces large amounts of air pollutants which are known to cause health problems, including ocular surface abnormalities. In this study, we evaluated the effect of biomass burning on mucus quality and mucin gene expression (MUC1, MUC5AC, MUC16) in the conjunctiva of sugarcane workers (SWs) and residents of an adjacent town (RTs). Impression cytology samples of the inferior tarsal and bulbar conjunctiva of 78 SWs and 32 RTs were collected before (T1) and immediately after (T2) a 6-month harvest period. The neutral, acid and total mucus content of goblet cells was determined by PAS and AB staining. The levels of MUC5AC, MUC1 and MUC16 mRNA in the conjunctiva were measured by real-time PCR. Compared to RTs, SWs had higher levels of bulbar acid mucus and MUC16 mRNA and tarsal MUC5AC mRNA at T2 and lower levels of neutral mucus at T1 and T2. In the SW group, MUC1 mRNA levels were higher at T2 than at T1, but the levels of neutral and acid mucus were similar. In the RT group, acid mucus decreased and neutral mucus increased in the bulbar and tarsal conjunctiva at T2. In conclusion, our findings show that sugarcane harvesting is associated with abnormalities in mucus quality and content and changes in mucin mRNA levels on the ocular surface. This may help explain the ocular inflammatory signs and symptoms observed in subjects exposed to air pollutants and high temperatures from sugarcane biomass burning.

Asthma prevalence disparities and differences in sociodemographic associations with asthma, between Native Hawaiian/Other Pacific Islander, Asian, and White adults in Hawaii - Behavioral Risk Factor Surveillance System (BRFSS), 2001-2010

OBJECTIVES

Despite high asthma prevalence, relatively little is known about the epidemiology of asthma in Hawaii or among Native Hawaiian/Other Pacific Islanders (NHOPI). We sought to better characterize racial/ethnic differences in asthma prevalence and in sociodemographic factors associated with asthma among Hawaii adults.

DESIGN

We conducted multivariable logistic regression using 2001-2010 Behavioral Risk Factor Surveillance System data from Hawaii, and computed adjusted prevalence and ratios.

RESULTS

Asthma prevalence markedly varied between self-identified census categories of race in Hawaii, with NHOPI having the highest estimates of both lifetime (20.9%, 95% confidence interval [CI]: 19.5%-22.4%) and current (12.2%, CI: 11.2%-13.3%) asthma. Highest asthma prevalence among NHOPI persisted after controlling for potential confounders and within most sociodemographic categories. Among females Asians reported the lowest asthma prevalence, whereas among males point estimates of asthma prevalence were often lowest for Whites. Females often had greater asthma prevalence than males of the same race, but the degree to which gender modified asthma prevalence differed by both race and sociodemographic strata. Gender disparities in asthma prevalence were greatest and most frequent among Whites, and for current asthma among all races. Sociodemographic factors potentially predictive of adult asthma prevalence in Hawaii varied by race and gender.

CONCLUSION

Asthma disproportionately affects or is recognized more often among women and NHOPI adults in Hawaii, and occurs less or is under-reported among Asian women. The sociodemographic characteristics included in this study's model did not explain asthma disparities between races and/or gender. This investigation provides a baseline with which to plan additionally needed prevention programs, epidemiological investigations, and surveillance for asthma in Hawaii.