Use of Cooking Fuels and Cataract in a Population-Based Study: The India Eye Disease Study

Association between dietary inflammation index and cataract: a population-based study from NHANES 2005-2008

Importance

Various studies have widely explored the association between index of dietary inflammation (DII) and occurrence of diseases. Accumulating evidence have revealed that a lower DII seems to be protective against a variety of diseases. Nevertheless, the association between DII and age-related cataract remains unclear.

Objective

To investigate the correlation between DII and age-related cataract in a representative sample of the American population.

Design setting and participants

This cross-sectional population-based study comprised 6,395 participants from the National Health and Nutrition Examination Survey (NHANES) conducted in cycles from 2005 to 2008. DII was calculated using dietary recall information, with higher scores indicating greater inflammatory potential of the diet. Age-related cataract was evaluated using cataract surgery as a surrogate measure. Covariates included sociodemographic factors, lifestyle factors, physical measures, and comorbidities. Logistic regression models were employed to assess the association between DII and cataract. The presence of a non-linear relationship was examined using restricted cubic spline analysis. Subgroup analysis was conducted to explore potential interaction effects. Data analysis was performed from September 1 to December 30, 2022.

Main outcomes and measures

Age-related cataract assessed through cataract surgery information obtained from a self-reported questionnaire.

Results

A total of 6,395 participants were included, with a mean (standard deviation, SD) age of 48.7 (15.3) years. Of these, 3,115 (48.7%) were male, 3,333 (52.1%) were non-Hispanic white, and 683 (10.7%) had cataract. The mean (SD) DII was -4.78 (1.74). After adjusting for all included covariates, DII showed a positive association with cataract, both as a continuous variable (odds ratio (OR): 1.054, 95% confidence interval (CI): 1.007-1.103, p = 0.023) and in quartiles, with the highest quartile compared to the lowest (OR: 1.555, 95% CI: 1.233-1.967, p < 0.001). Restricted cubic spline analysis revealed no evidence of a non-linear relationship (p for non-linearity 0.085). Subgroup analysis indicated no interaction effects among the studied covariates.

Conclusions and relevance

These findings suggest that a pro-inflammatory diet serves as a risk factor for the occurrence of cataracts.

Air Pollution and Chronic Eye Disease in Adults: A Scoping Review

PURPOSE

We conducted a scoping review of studies examining ambient air pollution as a risk factor for chronic eye disease influencing the lens, retina, and intraocular pressure in adults.

METHODS

Terms related to air pollution and eye disease outcomes were used to search for publications on Embase, Web of Science Core Collection, Global Health, PubMed, and the Cochrane Central Register of Controlled Trials from January 1, 2010, through April 11, 2022.

RESULTS

We identified 27 articles, focusing on the following non-mutually exclusive outcomes: cataract (n = 9), presbyopia (n = 1), retinal vein occlusion or central retinal arteriolar and venular equivalents (n = 5), intraocular pressure (IOP) (n = 3), glaucoma (n = 5), age-related macular degeneration (AMD) (n = 5), diabetic retinopathy (n = 2), and measures of retinal morphology (n = 3). Study designs included cross-sectional (n = 16), case-control (n = 4), and longitudinal (n = 7). Air pollutants were measured in 50% and 95% of the studies on lens and retina or IOP, respectively, and these exposures were assigned to geographic locations. Most research was conducted in global regions with high exposure to air pollution. Consistent associations suggested a possibly increased risk of cataract and retina-associated chronic eye disease with increasing exposure to particulate matter (PM2.5-PM10), NO2, NOx, and SO2. Associations with O3 were less consistent.

CONCLUSIONS

Accumulating research suggests air pollution may be a modifiable risk factor for chronic eye diseases of the lens and retina. The number of studies on each specific lens- or retina-related outcome is limited. Guidelines regarding the role of air pollution in chronic eye disease do not exist.

Exploring the links between indoor air pollutants and health outcomes in South Asian countries: a systematic review

Indoor air pollution (IAP) has adverse effects on the health of people, globally. The objective of this systematic review was to present the range of health problems studied in association with indoor air pollutants in South Asian countries. We searched five databases, including PubMed, Web of Science, Scopus, Google Scholar, and CAB Direct for articles published between the years 2000 and 2020. We retrieved 5,810 articles, out of which we included 90 articles in our review. Among South Asian countries, only five countries have published results related to relationship between indoor air pollutants and adverse health conditions. All studies have shown adversity of indoor air pollutants on human's health. We found indoor solid fuel burning as a key source of indoor air pollution in the included studies, while women and children were most affected by their exposure to solid fuel burning. More than half of the studies accounted particulate matter responsible for indoor air pollution bearing negative health effects. In the included studies, eyes and lungs were the most commonly affected body organs, exhibiting common symptoms like cough, breathing difficulty and wheezing. This might have developed into common conditions like respiratory tract infection, chronic obstructive pulmonary diseases and eye cataract. In addition to promote research in South Asian countries, future research should focus on novel digital ways of capturing effects of indoor air pollutants among vulnerable segments of the population. As a result of this new knowledge, public health agencies should develop and test interventions to reduce people's exposure levels and prevent them to develop adverse health outcomes.

Time trends and gender disparities of Chinese cataract burden and their predictions

AIM

To evaluate the trends and changes in the number and rates of disability-adjusted life years (DALYs) and prevalence of cataract in China between 1990 and 2019, and to predict the trends of cataract burden from 2020 to 2030.

METHODS

The Global Burden of Diseases (GBD) database was employed to collect the data on DALYs and the prevalence of cataract in China, which was distinguished by age and sex during the past three decades from 1990 to 2019, and then changes in the number and rates of cataract from 2020 to 2030 were predicted. All data were analyzed by the R program (version 4.2.2) and GraphPad Prism 9.0 statistics software.

RESULTS

The number of DALYs of cataract increased from 449 322.84 in 1990 to 1 087 987.61 in 2019, number of cataract cases increased from 5 607 600.94 in 1990 to 18 142 568.96 in 2019. The age-standardized DALY rates (ASDR) generally increased slightly [estimated annual percentage change (EAPC=0.1; 95%CI: -0.24 to 0.45), age-standardized prevalence rates (ASPR) also increased (EAPC=0.88; 95%CI: 0.6 to 1.15). Cataract burden increased with age and female gender. Among the causes of cataract, air pollution was the most important, followed by smoking, high fasting plasma glucose, and high body mass index (BMI). The burden of cataract is predicted to grow persistently from 2020 to 2030, the number of DALYs and prevalence for cataract will rise to 2 336 431 and 43 698 620 respectively by 2030, the ASDR is predicted to be 85/100 000 and ASPR will be 1586/100 000 in 2030, females will still be at greater risk of suffering from cataract than males.

CONCLUSION

The burden of cataract in China kept rising from 1990 to 2019. Increasing age and female gender are risk factors for cataract. Air pollution, smoking, high fasting plasma glucose, and high BMI are associated with cataract. The burden of cataract in China will gradually increase from 2020 to 2030, the elderly women in particular need attention. Our results may be of help for providing reference strategies to reduce cataract burden in the near future.

Long-Term Exposure to Ambient PM2.5 and Age-Related Cataracts among Chinese Middle-Aged and Older Adults: Evidence from Two National Cohort Studies

Cataract is one key cause of visual disability and blindness. Ambient particulate matter is more likely to increase cataract risk due to eye continuous exposure to the environment. However, less is known about whether long-term exposure to particulate matter 2.5 (PM2.5) is related to age-related cataracts. We conducted a population-based study among 22,298 adults from two multicenter cohort studies [China Family Panel Studies (CFPS) and Chinese Longitudinal Healthy Longevity Survey (CLHLS)]. The associations between PM2.5 and age-related cataracts were analyzed by Cox proportional hazard regression models, which were also stratified according to demographic characteristics. The restricted cubic spline (RCS) model was used to explore the dose-response relationships between PM2.5 and age-related cataracts. The population attributable fraction (PAF) was calculated to assess the burden of age-related cataracts that can be attributed to PM2.5. In the final analysis, 1897 participants reported age-related cataracts during follow-up. Long-term exposure to PM2.5 was associated with age-related cataracts, with HRs of 1.165 (1.130, 1.201), 1.138 (1.103, 1.173), and 1.091 (1.057, 1.126) for per 10 μg/m3 increase at one-, two-, and three-year before the end of follow-up, respectively. Furthermore, associations between PM2.5 and age-related cataracts were also demonstrated in RCS models. The PAF of age-related cataracts to PM2.5 in the total participants was 24.63%. Our research found that long-term exposure to PM2.5 may increase the risk of age-related cataracts, and age-related cataracts should be considered as an important public health issue due to air pollution.

The Association Between Solid Fuel Use and Visual Impairment Among Middle-Aged and Older Chinese Adults: Nationwide Population-Based Cohort Study

BACKGROUND

Indoor air pollution has been reported to have adverse effects on the eye; however, the health effects of exposure to cooking with solid fuels on visual impairment remain unclear in China.

OBJECTIVE

We aimed to examine the association between cooking with solid fuels and visual impairment, including distance visual impairment (DVI) and near visual impairment (NVI).

METHODS

Data were obtained from the China Health and Retirement Longitudinal Study, a nationwide survey of adults aged over 45 years who were enrolled in 2011 (Wave 1) and followed up in Wave 2 (2013), Wave 3 (2015), and Wave 4 (2018). We used Cox proportional hazards models to determine the association between solid fuels use and visual impairment. Additionally, the impact of switching cooking fuel types on vision function were examined through wave-specific data analysis (Wave 1 and Wave 4). Interaction and subgroup analyses were performed to explore the potential effect modifiers. Data were collected using the stratified multistage random sampling method and further analyzed using SPSS 27.0 and R 4.2.1 statistical software packages.

RESULTS

A total of 9559 middle-aged and older Chinese adults without visual impairment at baseline were included in the study, with 51.2% (n=4914) of the participants reporting that they cooked with solid fuels. During the follow-up period, 2644 (27.5%) and 3130 (32.6%) participants developed DVI and NVI, respectively. Compared with the clean fuel users, participants who cooked with solid fuels had a higher risk of DVI (hazards ratio [HR] 1.38, 95% CI 1.28-1.50) and NVI (HR 1.18, 95% CI 1.10-1.27). In addition, switching the cooking fuel type from clean to solid fuels was associated with an elevated risk of DVI (HR 1.51, 95% CI 1.15-1.98) and NVI (HR 1.39, 95% CI 1.06-1.82) compared to persistently using clean fuels during the follow-up period, although no protective effect of switching from solid to clean fuels on NVI was found (P=.52). In subgroup analysis, we found that cooking with solid fuels increased the risk of DVI in participants younger than 65 years (HR 1.41, 95% CI 1.28-1.55), men (HR 1.45, 95% CI 1.28-1.65), urban residents (HR 1.41, 95% CI 1.08-1.75), and smokers (HR 1.43, 95% CI 1.25-1.64). By contrast, negative effects of cooking with solid fuels on NVI were found in nonsmokers (HR 1.21, 95% CI 1.11-1.33) and urban residents (HR 1.20, 95% CI 1.10-1.37).

CONCLUSIONS

Cooking with solid fuels was associated with an increased risk of visual impairment among middle-aged and older Chinese adults. These findings indicate that promoting the utilization of clean fuels is conducive to reducing the burden of visual impairment for the public.

Impact of smokeless cooking fuel use on health status of women in a rural setting of eastern India

The sustainable development goals (SDG 7.1) reinforce to ensure that everyone has access to affordable, safe and renewable energy. In India, women are typically responsible for cooking and are most vulnerable to household air contaminants. We conducted a descriptive cross-sectional comparative study in Odisha, India between exclusive LPG (liquefied petroleum gas) users and non-LPG users. A total of 900 women, 450 from each group, were randomly selected. The LPG-users had a better predictor of physical, psychological, social, and environmental wellbeing than non-LPG users. We found the ophthalmic disorders (adjusted odds ratio (AOR) 2.87, 95% CI 1.16-7.10, p = .023), asthma (AOR 2.05, 95% CI 1.15-3.65, p = .015), and ALRI (acute lower respiratory infections) (AOR 9.19, 95% CI 2.06-40.96, p < .004) were significantly higher in non-LPG users in comparison to LPG users. Access to smokeless cooking fuel will improve women's quality of life by eliminating the consumption of biofuel and thereby providing a healthier cooking environment.

Association of biomass fuel use with the risk of vision impairment among Chinese older adults: a cohort study

Cooking with biomass fuels has been reported to have adverse effects on health. This study aims to explore the association between cooking with biomass fuels and vision impairment among Chinese older adults aged 65 years and above. This cohort study drew on data from the 2011/2012 wave and the 2014 follow-up wave of the Chinese Longitudinal Healthy Longevity Survey. Participants' visual function was examined through a vision screening test. Exposure to indoor biomass fuels was self-reported. Cox proportional hazards models were applied to explore the relationship between biomass fuel use and vision impairment. Additionally, we compared the risk of vision impairment between participants who switched cooking fuel types and those who did not. Subgroup and interaction analyses were conducted to explore the potential effect modifiers. A total of 4711 participants were included in this study. During the follow-up, 1053 (22.35%) participants developed vision impairment. Cooking with biomass fuels increased the risk of vision impairment by 40% (hazard ratio [HR]: 1.40, 95% confidence interval [CI]: 1.21-1.61). Participants who switched from clean fuels to biomass fuels had a greater risk of vision impairment than persistent clean fuel users (HR: 1.44, 95% CI: 1.03-2.00). Greater effect estimates were found in participants who lived in eastern and central China and urban residents. Cooking with biomass fuels resulted in a greater risk of vision impairment among Chinese older adults. This risk also existed in those who changed their cooking fuels from clean fuels to biomass fuels. Further studies with an objective assessment of biomass fuel combustion are required to confirm our findings.

Association of solid fuel use with a risk score capturing dementia risk among middle-aged and older adults: A prospective cohort study

OBJECTIVES

Whether household air pollution is associated with dementia risk remains unknown. This study examined the associations between solid fuel use for cooking and heating (the main source of household air pollution) and dementia risk.

METHODS

This analysis included data on 11,352 participants (aged 45+ years) from the 2011 wave of China Health and Retirement Longitudinal Study, with follow-up to 2018. Dementia risk was assessed by a risk score using the Rotterdam Study Basic Dementia Risk Model (BDRM), which was subsequently standardized for analysis. Household fuel types of cooking and heating were categorized as solid (e.g., coal and crop residue) and clean (e.g., central heating and solar). Multivariable analyses were performed using generalized estimating equations. Moreover, we examined the joint associations of solid fuel use for cooking and heating with the BDRM score.

RESULTS

After adjusting for potential confounders, we found an independent and significant association of solid (vs. clean) fuel use for cooking and heating with a higher BDRM score (e.g., β = 0.17 for solid fuel for cooking; 95% confidence interval [CI]: 0.15-0.19). Participants who used solid (vs. clean) fuel for both cooking and heating had the highest BDRM score (β = 0.32; 95% CI: 0.29-0.36). Subgroup analysis suggested stronger associations in participants living in rural areas.

CONCLUSIONS

Solid fuel use for cooking and heating was independently associated with increased dementia risk in Chinese middle-aged and older adults, particularly among those living in rural areas. Our findings call for more efforts to facilitate universal access to clean energy for dementia prevention.

Indoor air pollution and human ocular diseases: Associated contaminants and underlying pathological mechanisms

People spend a long time indoors, especially young children. The risk of indoor pollution on human health is one of the current hotspots in environmental and public health. The human ocular surface is highly susceptible to indoor environment quality. Epidemiological data have linked human ophthalmological disorders with exposure to indoor pollution. In this review, we summarized the adverse impacts of indoor pollution on the human ocular surface. Several studies demonstrated that indoor contaminants including particulate matter, volatile/semi-volatile organic compounds, heavy metals, and fuel combustion and cigarette smoke exposure were associated with the incidence of human dry eye, conjunctivitis, glaucoma, cataracts, age-related macular degeneration, and keratitis. In addition, toxicological investigations revealed that indoor pollution-induced induced chronic inflammation, oxidative damage, and disruption of tight junctions are the main underlying pathological mechanisms for ocular surface diseases. Taken together, this review may expand the understanding of pollution-induced eye disorder and highlight the importance of reducing associated contaminants to decrease their detrimental effects on human eyes.

Biomass use and its health effects among the vulnerable and marginalized refugee families in the Gaza Strip

Introduction

Biomass fuel remains the most common type of fuel used in many developing countries, leading to indoor air pollution and serious health impacts.

Objective

The objective of this study was to compile evidence on the impact household fuel combustion has on child and adult health, with an emphasis on solid fuel use in Gaza.

Methods

In this cross-sectional study, 110 structured self-administered questionnaires were distributed in April 2019 among families living in the Al-Maghazi refugee camp.

Results

Participants reported that the main fuel used were wood, coal, cardboard, and a mix of wood, cardboard, and plastic, which were used for cooking, heating, baking, boiling water, and lighting. The most common symptoms were nasal irritation (71.8%), followed by headache (66.4%) and dizziness (65.4%). The results of logistic regression showed that the participants who used wood fuel had a higher chance of feeling eye irritation than those who used a mix of wood, cardboard, and dried grass (OR = 1.316; 95% CI = 1.54-8.99). The participants who opened windows during the burning process of biomass fuel were five times more likely to develop pneumonia than those who closed windows (OR = 5.53; 95%CI = 11.60-19.0).

Conclusion

there is an urgent need for community awareness campaigns designed to inform people about the risks of exposure to biomass fuel smoke and how to better implement household ventilation.

Changing Trends in the Disease Burden of Cataract and Forecasted Trends in China and Globally from 1990 to 2030

Aim

To explore the trends in the prevalence and disease burden of cataract from 1990 to 2019, evaluate attributable risk factors, and predict trends over the next decade in China and globally.

Methods

Data was obtained from Global Burden of Disease Study 2019. We calculated the age-standardized prevalence rate (ASR) and annual percentage change (EAPC) to show the trends of cataract in China and different regions. We calculated and reported the proportion of disability adjusted life years (DALYs) attributable to risk factors by sex in China and different regions. Then, the Bayesian age-period-cohort (BAPC) analysis model was also used to predict the prevalence trends from 2020 to 2030 in China and globally.

Results

The ASR increased from 867.09 in 1990 to 991.56 in 2019 per 100,000 with an EAPC of 0.88 in China. The age-standardized DALY rate of females was higher than males. DALY rates were correlated to household air pollution from solid fuels, tobacco, high fasting plasma glucose and high body-mass index. The projective model indicates that the ASR for cataracts will rise to 1101.35×10⁶ for male and 1616.63×10⁶ for female by 2030.

Conclusion

The trends from 1990 to 2030 suggested that the burden of cataract remains high in China. Maintaining good lifestyle habits such as switching to clean energy, reducing cigar intake, controlling blood glucose and weight can reduce the risk of cataracts. As aging increases, China should pay more attention to cataract-induced low vision and blindness and develop public policies to reduce the disease burden.

Exposure to indoor air pollution and the cognitive functioning of elderly rural women: a cross-sectional study using LASI data, India

BACKGROUND

The majority of people in rural developing counties still rely on unclean and solid fuels for cooking, putting their health at risk. Adult and elderly women are most vulnerable due to prolonged exposure in cooking areas, and Indoor Air Pollution (IAP) may negatively impact their health and cognitive function. This study examines the effect of IAP on the cognitive function of middle-aged and elderly rural women in India.

METHODS

The study utilized the data from the Longitudinal Ageing Study in India (LASI 2017-18, Wave-1). Bivariate analysis and multilevel linear regression models were applied to show the association between IAP and the cognitive abilities of rural women and results from regression were presented by beta coefficient (β) with 95% confidence interval (CI). Confounding factors such as age, education, health risk behaviours, marital status, monthly per capita consumption expenditure (MPCE), religion etc. were adjusted in the final model.

RESULTS

The study found that 18.71 percent of the rural women (n = 3,740) lived in Indoor Air Pollution exposed households. IAP was significantly found to be associated with the cognitive functional abilities among the middle and older aged rural women. Middle and older aged rural women exposed to IAP had lower cognitive functional abilities than non-exposed women. Comparing to the non-exposed group, the cognitive score was worse for those exposed to IAP in both the unadjusted (β = -1.96; 95%CI: -2.22 to -1.71) and the adjusted (β = -0.72; 95%CI: -0.92 to -0.51) models. Elderly rural women from lower socioeconomic backgrounds were more likely to have cognitive impairment as a result of IAP.

CONCLUSION

Findings revealed that IAP from solid fuels could significantly affect the cognitive health of elderly rural women in India, indicating the need for immediate intervention efforts to reduce the use of solid fuels, IAP and associated health problems.

Association between cooking fuels and mild cognitive impairment among older adults from six low- and middle-income countries

There is a small body of evidence suggesting that unclean cooking fuel use may be associated with cognitive decline. However, to date, no study has investigated the association between unclean cooking fuel and mild cognitive impairment (MCI). Thus, we investigated the association between cooking fuel type or ventilation type and MCI among adults aged ≥ 65 years using nationally representative datasets from six low- and middle-income countries. Cross-sectional, community-based data from the World Health Organization (WHO) Study on global Ageing and adult health (SAGE) were analyzed. MCI was defined using the National Institute on Aging-Alzheimer's Association criteria. Unclean cooking fuel referred to kerosene/paraffin, coal/charcoal, wood, agriculture/crop, animal dung, and shrubs/grass. Multivariable logistic regression analysis was conducted to assess associations. Data on 13,623 individuals were analyzed [mean (SD) age 72.8 (11.0) years; 45.5% males]. Unclean cooking fuel (vs. clean cooking fuel) was associated with a significant 1.48 (95% CI = 1.08–2.03) times higher odds for MCI. Having no chimney or hood for cooking ventilation was also associated with significantly higher odds for MCI (OR = 1.88; 95% CI = 1.25–2.84). Unclean cooking fuel use and lack of chimney or hood for cooking ventilation were associated with higher odds for MCI. Findings support the implementation of the United Nations Sustainable Goal 7, which advocates affordable, reliable, sustainable, and modern energy for all, as this may also help reduce MCI and ultimately dementia.

Relationship between cooking fuel and lens opacities in South India: a 15-year prospective cohort study

PURPOSE

Unclean cooking fuels such as wood and kerosene have been associated with cataract in cross-sectional studies. This study sought to determine whether exposure to unclean cooking fuels was associated with subsequent cataract progression.

DESIGN

Prospective cohort study.

METHODS

This is a secondary observational analysis of the community-based Antioxidants in Prevention of Cataracts trial (ClinicalTrials.gov ID NCT01664819). The exposure of interest was cooking fuel type, measured at baseline. Main outcome measures were baseline cataract severity and self-reported cataract surgery at a 15-year visit.

RESULTS

Baseline and 15-year follow-up data were available for 798 and 579 participants, respectively. Wood or kerosene was used by 711/798 (89.1%) baseline participants, including 539/579 (93.1%) participants with complete follow-up. Cooking fuel type was not associated with cataract severity at baseline (p=0.443). Out of 8,334 person-years of follow up, 90 cataract surgeries were observed over 15 years (1.08 surgeries per 100 person-years; 95%CI 0.87-1.32). Use of wood or kerosene was not associated with 15-year incidence of cataract surgery relative to individuals using propane (adjusted p=0.154). Cataract surgery was more common in older individuals (HR 1.1 per year, 95%CI 1.1-1.2, p<0.001), those with baseline myopia (HR 2.1, 95%CI 1.2-3.5, p=0.009) and women (HR 3.5, 95%CI 1.2 to 10.1, p=0.019).

CONCLUSIONS

This study found no association between unclean cooking fuels and cataract progression over a 15-year period. No other modifiable risk factors were associated with incident self-reported cataract surgery.

Use of unclean cooking fuels and visual impairment of older adults in India: A nationally representative population-based study

Despite widespread use of unclean cooking fuels (UCF) in India, evidence from nationally representative data on its association with visual impairment was lacking. We used a population-based nationwide survey of adults aged 45 years and older that included reported UCF and measured visual impairment. We estimated that 44.8% (95% CI: 42.6, 47.1) of older adults in India lived in households that used UCF. Age- and sex-adjusted prevalence of visual impairment was estimated to be 33.0% (95% CI: 31.0, 34.9) in the older population that did not use UCF and 9.0 percentage points (pp) (95% CI: 8.9, 9.1) higher among those who did. Among those who used UCF, age- and sex-adjusted prevalence of low distance vision was 4.3 pp (95% CI: 4.2, 4.4) higher, prevalence of low near vision was 8.0 pp (95% CI: 7.9, 8.1) higher, and prevalence of blindness was 1.0 pp (95% CI: 0.9, 1.0) higher. After controlling for a rich array of sociodemographic characteristics and state fixed effects, we estimated that use of UCF was associated with higher prevalence of visual impairment by 3.2 pp (95% CI: 1.4, 5.0), low distance vision by 1.8 pp (95% CI: 0.7, 2.9), and low near vision by 3.2 pp (95% CI: 1.3, 5.0). Doubly robust estimates of these differences were slightly larger. Blindness was not significantly partially associated with use of UCF (95% CI: -0.4, 0.6). We did not find support for the hypotheses that the visual impairment risk associated with use of UCF was even larger for females and in households without a separate kitchen or ventilation. The older population of India is highly reliant on UCF that is very strongly associated with visual impairment. Impaired vision should not be overlooked among the harms associated with UCF.

The Association of Ambient Air Pollution With Cataract Surgery in UK Biobank Participants: Prospective Cohort Study

Purpose

Air pollution is associated with chronic diseases of later life. Cataract is the most common cause of blindess globally. It is biologically plausible that cataract risk is increased by pollution exposure. Therefore, the relationship between air pollution and incident cataract surgery was examined.

Methods

This was a prospective, observational study involving 433,727 UK Biobank participants. Ambient air pollution measures included particulates, nitrogen dioxide (NO2) and nitrogen oxides (NOx). Outdoor air pollution was estimated based on land use regression models. Participants undergoing cataract surgery in either eye were ascertained via data linkage to the National Health Service procedure statistics. Those undergoing cataract surgery within 1 year of baseline assessment and those reporting cataract at baseline were excluded. Cox proportional hazards models were used to examine the associations between air pollutants and incident cataract surgery, adjusting for sociodemographic and lifestyle factors.

Results

There were 16,307 incident cases of cataract surgery. Higher exposure to PM2.5 was associated with a 5% increased risk of incident cataract surgery (per interquartile range [IQR] increase). Compared to the lowest quartile, participants with exposures to PM2.5, NO2, and NOx in the highest quartile were 14%, 11%, and 9% more likely to undergo cataract surgery, respectively. A continuous exposure-response relationship was observed, with the likelihood of undergoing cataract surgery being progressively higher with greater levels of PM2.5, NO2, and NOx (P for trend P < 0.001).

Conclusions

Although the results of our study showed a 5% increased risk of future cataract surgery following an exposure to PM2.5, NO2, and NOx, the effect estimates were relatively small. Further research is required to determine if the associations identified are causal.

The association of cooking fuels with cataract among adults aged 50 years and older in low- and middle-income countries: Results from the WHO Study on global AGEing and adult health (SAGE)

Reducing household air pollution and protecting eye health are essential to achieve the Sustainable Development Goals (SDGs). There is contradictory evidence about the association between cooking fuels and cataract among adults aged 50 years and older. WHO Study on global AGEing and adult health (SAGE) was conducted in six low- and middle-income countries (LMICs). We used propensity-score method (inverse probability of weighting) and logistic regression to examine the association between cooking fuels and self-reported cataract. Odds ratio (OR) estimates and 95% confidence intervals (CIs) were calculated. Overall, use of unclean fuels was associated with an adjusted OR of cataract of 1.42 (95%CIs, 1.29-1.56). In subgroup analysis, unclean cooking fuels increased 1.71 (95%CI, 1.46-2.01) and 1.53 (95%CI, 1.30-1.79) times the risk of cataract in India and China, respectively, whereas no association was found in other countries. In gender-stratified analyses, unclean fuel use was associated with a 1.27 (95%CI, 1.13-1.44) times risk for males and 1.67 (95%CI, 1.44-1.94) times risk for females. Higher cataract risk attributed to unclean fuels was observed among those aged over 60 (1.45; 95%CI, 1.28-1.64) than people aged under 60 (1.39; 95%CI, 1.20-1.62). OR was higher in rural area (1.74; 95%CI, 1.51-2.00) than urban area (1.24; 95%CI, 1.09-1.41). Our results indicate that unclean fuels may be associated with self-reported cataract, but it varied among different LMICs. Higher risk was found in females, people older than 60 years old and those who live in rural areas. The result of this study provides useful information to support transition to clean household energy and eye health promotion in LMICs. Greater efforts should be taken to protect vulnerable populations.

Seven-year trends in cataract surgery indications and quality of outcomes at Aravind Eye Hospitals, India

PURPOSE

To report trends in cataract surgery indications, visual acuity outcomes, complication rates and reoperation rates at ten Aravind Eye Hospitals in Tamil Nadu, India.

METHODS

In this retrospective database study we analyzed seven years of data of cataract surgeries at Aravind during January 1, 2012 to December 31, 2018. Our main outcome measures were preoperative and 1-month postoperative uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA); and rates of intraoperative complications and reoperations. We performed Cochran-Armitage trend tests.

RESULTS

In 1.86 million eyes that underwent cataract surgery, the percentage of eyes undergoing phacoemulsification (PE) showed an increasing trend (p < 0.0001), from 26.8% in 2012 to 33.5% in 2018. The percentage of eyes undergoing manual small incision cataract surgery (SICS) showed a decreasing trend (p < 0.0001), from 70.0% in 2012 to 65.1% in 2018. For SICS, the percentages of eyes with good postoperative UCVA and BCVA showed increasing trends (p < 0.0001 for each), and the percentages of eyes with poor postoperative UCVA and BCVA showed decreasing trends (p < 0.0001 for each). Results for PE surgeries were mixed. For both PE and SICS rates of intraoperative complications showed a declining trend (p < 0.0001 for each) and a slight increasing trend for reoperations (PE p < 0.02; SICS p < 0.0001).

CONCLUSIONS

During this seven-year period there were noticeable trends in cataract surgeries performed at Aravind in terms of the mix of surgical procedures, preoperative vision, and cataract surgical outcomes.

Long-term solid fuel use and risks of major eye diseases in China: A population-based cohort study of 486,532 adults

BACKGROUND

Over 3.5 billion individuals worldwide are exposed to household air pollution from solid fuel use. There is limited evidence from cohort studies on associations of solid fuel use with risks of major eye diseases, which cause substantial disease and economic burden globally.

METHODS AND FINDINGS

The China Kadoorie Biobank recruited 512,715 adults aged 30 to 79 years from 10 areas across China during 2004 to 2008. Cooking frequency and primary fuel types in the 3 most recent residences were assessed by a questionnaire. During median (IQR) 10.1 (9.2 to 11.1) years of follow-up, electronic linkages to national health insurance databases identified 4,877 incident conjunctiva disorders, 13,408 cataracts, 1,583 disorders of sclera, cornea, iris, and ciliary body (DSCIC), and 1,534 cases of glaucoma. Logistic regression yielded odds ratios (ORs) for each disease associated with long-term use of solid fuels (i.e., coal or wood) compared to clean fuels (i.e., gas or electricity) for cooking, with adjustment for age at baseline, birth cohort, sex, study area, education, occupation, alcohol intake, smoking, environmental tobacco smoke, cookstove ventilation, heating fuel exposure, body mass index, prevalent diabetes, self-reported general health, and length of recall period. After excluding participants with missing or unreliable exposure data, 486,532 participants (mean baseline age 52.0 [SD 10.7] years; 59.1% women) were analysed. Overall, 71% of participants cooked regularly throughout the recall period, of whom 48% used solid fuels consistently. Compared with clean fuel users, solid fuel users had adjusted ORs of 1.32 (1.07 to 1.37, p < 0.001) for conjunctiva disorders, 1.17 (1.08 to 1.26, p < 0.001) for cataracts, 1.35 (1.10 to 1.66, p = 0.0046) for DSCIC, and 0.95 (0.76 to 1.18, p = 0.62) for glaucoma. Switching from solid to clean fuels was associated with smaller elevated risks (over long-term clean fuel users) than nonswitching, with adjusted ORs of 1.21 (1.07 to 1.37, p < 0.001), 1.05 (0.98 to 1.12, p = 0.17), and 1.21 (0.97 to 1.50, p = 0.088) for conjunctiva disorders, cataracts, and DSCIC, respectively. The adjusted ORs for the eye diseases were broadly similar in solid fuel users regardless of ventilation status. The main limitations of this study include the lack of baseline eye disease assessment, the use of self-reported cooking frequency and fuel types for exposure assessment, the risk of bias from delayed diagnosis (particularly for cataracts), and potential residual confounding from unmeasured factors (e.g., sunlight exposure).

CONCLUSIONS

Among Chinese adults, long-term solid fuel use for cooking was associated with higher risks of not only conjunctiva disorders but also cataracts and other more severe eye diseases. Switching to clean fuels appeared to mitigate the risks, underscoring the global health importance of promoting universal access to clean fuels.

Incidence, Incident Causes, and Risk Factors of Visual Impairment and Blindness in a Rural Population in India: 15-Year Follow-up of the Andhra Pradesh Eye Disease Study

PURPOSE

To report 15-year incidence rate of visual loss (blindness and visual impairment [VI]), causes, and risk factors for participants in Andhra Pradesh Eye Disease Study III (APEDS III).

DESIGN

Population-based cohort study.

METHODS

From 2012 to 2016, all rural participants were interviewed and underwent a comprehensive eye examination, including dilated fundus examination and imaging. Presenting visual acuity (PVA) and best-corrected visual acuity (BCVA) were measured using a standard logarithm of Minimum Angle of Resolution chart at 3 meters. World Health Organization (WHO) and United States of America (USA) categories of VI and blindness were used. Incident visual loss was defined as the development of or worsening of visual loss of one or more categories.

RESULTS

In APEDS I, 7,771 rural participants were examined using stratified, random-cluster systematic sampling; in APEDS III, 5,395 participants (69.4% of rural or 52.4% of total participants) were re-examined. Using WHO categories, the crude incidence rate of any visual loss based on PVA and BCVA were 14.6 (95% confidence interval [CI]:13.6-15.7) and 6.3 (95% CI: 6.1-6.4) per 100 person-years, respectively. Using USA criteria, the values were 22.6 (95% CI: 22.3-23.0) and 10.6 (95% CI: 10.3-10.8) per 100 person-years, respectively. More than 90% of visual loss was attributable to cataract and uncorrected refractive error. Using WHO categories, significant independent risk factors for the incident visual loss were increasing age, female gender, illiteracy, past or current smoker, and current use of alcohol. Using the USA definition, an additional risk factor was lower level of education.

CONCLUSIONS

The high incidence likely reflects poor access to eye care in this population, which needs to be taken into account when planning eye care programs.

Adverse Birth Outcomes Due to Exposure to Household Air Pollution from Unclean Cooking Fuel among Women of Reproductive Age in Nigeria

Exposure to household air pollution (HAP) from cooking with unclean fuels and indoor smoking has become a significant contributor to global mortality and morbidity, especially in low- and middle-income countries such as Nigeria. Growing evidence suggests that exposure to HAP disproportionately affects mothers and children and can increase risks of adverse birth outcomes. We aimed to quantify the association between HAP and adverse birth outcomes of stillbirth, preterm births, and low birth weight while controlling for geographic variability. This study is based on a cross-sectional survey of 127,545 birth records from 41,821 individual women collected as part of the 2018 Nigeria Demographic and Health Survey (NDHS) covering 2013-2018. We developed Bayesian structured additive regression models based on Bayesian splines for adverse birth outcomes. Our model includes the mother's level and household characteristics while correcting for spatial effects and multiple births per mother. Model parameters and inferences were based on a fully Bayesian approach via Markov Chain Monte Carlo (MCMC) simulations. We observe that unclean fuel is the primary source of cooking for 89.3% of the 41,821 surveyed women in the 2018 NDHS. Of all pregnancies, 14.9% resulted in at least one adverse birth outcome; 14.3% resulted in stillbirth, 7.3% resulted in an underweight birth, and 1% resulted in premature birth. We found that the risk of stillbirth is significantly higher for mothers using unclean cooking fuel. However, exposure to unclean fuel was not significantly associated with low birth weight and preterm birth. Mothers who attained at least primary education had reduced risk of stillbirth, while the risk of stillbirth increased with the increasing age of the mother. Mothers living in the Northern states had a significantly higher risk of adverse births outcomes in 2018. Our results show that decreasing national levels of adverse birth outcomes depends on working toward addressing the disparities between states.

Association between Exposure to Ambient Air Pollution and Age-Related Cataract: A Nationwide Population-Based Retrospective Cohort Study

This study aimed to investigate the association between ambient air pollutants and cataracts in the general population aged 50 years or older using data from the Korean National Insurance Service-National Sample Cohort. Cataract patients were defined as those diagnosed by a physician and having undergone cataract surgery. After matching the average concentrations of PM2.5, PM10, NO2, CO, SO2, and O3 in residential areas, the association between quartile level of air pollutants and incidence of cataract was analyzed using a multivariate Cox-proportional hazard risk model. Among the 115,728 participants, 16,814 (14.5%) were newly diagnosed with cataract and underwent related surgery between 1 January 2004, and 31 December 2015. Exposure to PM10, NO2, and SO2 was positively associated with cataract incidence, while O3 was negatively associated. The adjusted hazard ratio (HR) with 95% confidence interval was 1.069 (1.025-1.115) in PM10 and 1.080 (1.030-1.133) in NO2. However, the association between cataract and the quartile of PM2.5 measured during one year in 2015 was not clear. The HR of female participants aged 65 or older was significantly increased according to quartile of air pollutants. We identified exposure to PM10, NO2, SO2, and O3 associated with cataract development in Korean adults aged ≥ 50 years. This information may be helpful for policymaking to control air pollution as a risk factor for eye health.

The Association between Socioeconomic Factors and Visual Function among Patients with Age-Related Cataracts

Background

With the development of the economy, socioeconomic factors, such as inequalities in the status of regional economies and the subsequent effects on health systems, have influenced the status of health. We explored the association between age-related cataracts and socioeconomic indicators, including the regional economy, health systems, and energy industries.

Methods

This was a prospective, multicenter, Chinese population-based, cross-sectional study. A total of 830 participants from seven centers were enrolled. Data on the best-corrected visual acuity (BCVA), Lens Opacities Classification System III (LOCS III) score, Visual Function Index-14 (VF-14) score, total and subscale scores of the 25-item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25), per capita disposable income (PCDI), medical resource-related indicators, and investments in the energy industry were obtained. Associations among these parameters were analyzed.

Results

The PCDI ranking was correlated with the VF-14 score (R = -0.426, P < 0.01), total score of NEI-VFQ-25 (r = -0.500, P < 0.01), and BCVA (r = 0.278, P < 0.01). The number of health agencies (r1 = 0.267, r2 = -0.303, r3 = -0.291,), practicing or assistant practicing doctors (r1 = -0.283, r2 = 0.427, r3 = 0.502,), registered nurses (r1 = -0.289, r2 = 0.409, r3 = 0.469, P < 0.01), and health technicians (r1 = -0.278, r2 = 0.426, r3 = 0.500, P < 0.01) per 10,000 of the population was each correlated with the BCVA, VF-14 score, and total score of NEI-VFQ-25, respectively. Health expenditure per capita was correlated with the VF-14 score (r = 0.287, P < 0.01) and total score of NEI-VFQ-25 (r = 0.459, P < 0.01). The LOCS III P score was correlated with investments in the energy industry (r = 0.485, P < 0.001).

Conclusions

Patients in higher economic regions with greater medical resources show a greater demand to undergo cataract surgery at a better subjective and objective visual function. The energy industry has a significant effect on cataracts, especially the posterior subcapsular cataract, and thus more attention should be paid to people in regions with abundant energy industries.

Prediction Model for Dry Eye Syndrome Incidence Rate Using Air Pollutants and Meteorological Factors in South Korea: Analysis of Sub-Region Deviations

Here, we develop a dry eye syndrome (DES) incidence rate prediction model using air pollutants (PM₁₀, NO₂, SO₂, O₃, and CO), meteorological factors (temperature, humidity, and wind speed), population rate, and clinical data for South Korea. The prediction model is well fitted to the incidence rate (R² = 0.9443 and 0.9388, p < 2.2 × 10⁻¹⁶). To analyze regional deviations, we classify outpatient data, air pollutant, and meteorological factors in 16 administrative districts (seven metropolitan areas and nine states). Our results confirm NO₂ and relative humidity are the factors impacting regional deviations in the prediction model.

Association between biomass fuel use and risk of hypertension among Chinese older people: A cohort study

BACKGROUNDS

Previous studies linking biomass fuel use to hypertension have been inconsistent. We investigated the association between biomass fuel use and the risk of hypertension and blood pressure measures in older Chinese people.

METHODS

The prospective cohort study of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) included participants aged 65 years and older in 2011/2012 who were followed up until 2014 in 23 provinces in China. We explored the association between biomass fuel use and hypertension using the Cox proportional hazards model and examined the relationship of biomass fuel use with blood pressure measures using the generalized estimating equation. Additionally, we examined the effect of switching cooking fuels on hypertension during the follow-up.

RESULTS

Among 3754 participants who were without hypertension at baseline, the mean age was 86 years old, and 47.5% of participants were men. Reported use of biomass fuel for cooking (50.2%) was associated with a higher risk of hypertension (incidence rate (IR) per 100 person-years: 13.15 versus 12.99, hazard ratio (HR) = 1.15, 95% confidence interval (CI) = 1.01-1.31). Biomass fuel use was related to systolic blood pressure (SBP) (β 1.10 mmHg, 95% CI: 0.48-1.72), diastolic blood pressure (DBP) (β 1.02 mmHg, 95% CI: 0.61-1.43) and mean arterial pressure (MAP) (β 1.03 mmHg, 95% CI: 0.63-1.43) elevation. Compared with persistent clean fuel users, participants who reported switching from clean to biomass fuels for cooking had a noticeably higher risk of hypertension (IR per 100 person-years: 14.27 versus 12.81, HR 1.49, 95% CI: 1.16-1.90) and higher SBP (3.71 mmHg), DBP (2.44 mmHg) and MAP (2.86 mmHg). Interaction and stratified analyses showed greater effect estimates of SBP and MAP in the oldest oldpeople (≥85).

CONCLUSIONS

The use of biomass fuel for cooking was associated with greater hypertension risk, and the risk may be higher among those who switched from clean fuels to biomass fuels in the Chinese elderly population. Biomass fuel use was associated with a statistically significant but small absolute increase in blood pressure measures.

Household cooking fuel use and its health effects among rural women in southern India-A cross-sectional study

The use of biomass fuel is associated with the deterioration of human health and women are more likely to develop health conditions due to their exposure to indoor air pollution during cooking. This study was conducted to assess the pattern of fuel used for cooking in households as well as to determine the association between the types of fuel used with respect to socio-demographic characteristics and health status of women. A community based cross-sectional survey was conducted between August 2016 and September 2018 in four rural areas and one semi-urban area of Udupi district, Karnataka, India. The study comprised 587 families including 632 women. A pre-tested semi-structured questionnaire was used to collect data on the type of fuel as well as self-reported health conditions. Overall, 72.5% of the families used biomass, where 67.2% families were currently using both biomass and liquefied petroleum gas while only biomass was used in 5.3% of the families for cooking. Among women, being ever exposed to biomass fuel was significantly associated with their age, literacy level, occupation and socio-economic status (p < 0.001). Those who were exposed to biomass fuel showed a significant association with self-reported ophthalmic (AOR = 3.85; 95% CI: 1.79–8.29), respiratory (OR = 5.04; 95% CI: 2.52–10.07), cardiovascular (OR = 6.07; 95% CI: 1.88–19.67), dermatological symptoms /conditions (AOR = 3.67; 95% CI: 1.07–12.55) and history of adverse obstetric outcomes (AOR = 2.45; 95% CI: 1.08–5.57). A positive trend was observed between cumulative exposure to biomass in hour-years and various self-reported health symptoms/conditions (p < 0.001). It was observed that more than two-thirds of women using biomass fuel for cooking were positively associated with self-reported health symptoms. Further longitudinal studies are essential to determine the level of harmful air pollutants in household environment and its association with various health conditions among women in this region.

Incidence of ocular conditions associated with perfluoroalkyl substances exposure: Isomers of C8 Health Project in China

The detrimental effects of perfluoroalkyl substances (PFASs) on several physiological systems have been reported, but the association of PFASs with eye, one of the most sensitive and exposed organ, has never been explored. To investigate the association between eye diseases including visual impairment (VI) and PFASs isomers, a cross-sectional stratified study was conducted in 1202 Chinese population, aged 22-96 years, from Shenyang, China. A standard protocol including Snellen vision chart, slit-lamp microscopy and direct ophthalmoscopy was used to examine eye diseases/conditions relating to anterior and posterior segment of eyes. In addition, we measured the blood concentrations of 19 linear and branched PFASs at one-time point. Results indicated that blood levels of PFASs were significantly higher in eye disease group than normal group. PFASs exposure were positively associated with both combined eye diseases and individual eye diseases. Among other PFASs, linear perfluorooctane sulfonate (n-PFOS; odds ratio [OR] = 3.37, 95% confidence interval [CI]: 2.50, 4.56), branched perfluorooctane sulfonate (Br-PFOS; OR = 2.25, 95% CI: 1.72, 2.93) and linear perfluorooctanoic acid (n-PFOA; OR = 1.79, 95% CI: 1.36, 2.37) significantly increases the odds of VI. Vitreous disorder was adversely associated with long-chain PFASs exposure. For example, perfluorotridecanoic acid (PFTrDA; OR = 1.86, 95% CI: 1.51, 2.29) and perfluorodecanoic acid (PFDA; OR = 1.79, 95% CI: 1.36, 2.36) showed the most significant association. In conclusion, this study suggests higher serum PFASs levels were associated with increase odds of VI and vitreous disorder in Chinese adults.

Household Air Pollution from Cooking Fires Is a Global Problem

Over the past several decades, important advances have been made in the United States to ensure that our residents breathe clean air. Still, nearly 12 million homes in this country burn wood for heating. Globally, 3 billion people, or close to half of the world's population, depend on polluting solid fuels such as wood for daily cooking and heating. Unlike in the United States where stoves used for heating are vented, many homes in low-income countries use simple stoves that often lack chimneys, leading to toxic amounts of smoke inside and outside the home. Household air pollution from these fires is the 16th leading risk factor for death and disability worldwide. Childhood pneumonia, chronic obstructive pulmonary disease, and cardiovascular disease have all been associated with household air pollution globally, yet many nurses are not aware of this burden when caring for immigrants and refugees residing in the United States. Global organizations are working to provide access to clean cookstoves (those that run on electricity, solar power, or liquid fuel), and nurses can get involved. This is one step toward improving the lives of vulnerable populations in the United States and worldwide. This series is in collaboration with the Alliance of Nurses for Healthy Environments (https://envirn.org).

Depression in the house: The effects of household air pollution from solid fuel use among the middle-aged and older population in China

BACKGROUND

Although the adverse health effects of ambient air pollution are well documented, evidence on the depression effects of household air pollution (HAP) are scarce.

OBJECTIVES

We investigated the effects of HAP exposure from the use of solid fuel on depression using a nationally representative dataset of middle-aged and older population in China.

METHODS

By employing the propensity score matching method, we first matched the type of household fuel based on background information, including demographic characteristics, lifestyles, health status, and household economic levels. Based on the matched data, we conducted OLS and logistic regressions with cluster standard error at community level to examine the effects of household solid fuel use on depression and adjusted for potential confounders. Heterogeneous effects for vulnerable population were also considered.

RESULTS

We found a significantly higher Center for Epidemiologic Studies Depression Scale (CES-D) score and depression risk among current household solid fuel users. After matching and adjusting for potential confounders, current solid fuel users had a higher CES-D score of 0.59 (95% confidence interval [CI]: 0.31, 0.89) than clean fuel users. The OR of depression risk were 1.26 (95% CI: 1.14, 1.41). Solid fuel users had the highest CES-D scores (β = 0.99, 95% CI: 0.62, 1.36) and depression risk (OR = 1.49, 95% CI: 1.30, 1.73) for over five years. These associations were generally higher in females, participants aged 65 years and older, with a BMI ≥ 25, with low education, with low household economic levels, and those suffer from chronic diseases, including diabetes, chronic lung diseases, and cardiovascular diseases.

CONCLUSIONS

Exposure to HAP from solid fuel combustion was linked with strong depression outcomes. Findings suggested a need to strengthen public health efforts, such as controlling the social, health, and economic costs of depression by taking the physical environment, including HAP exposure, into account.

Association of cataract and sun exposure in geographically diverse populations of India: The CASE study. First Report of the ICMR-EYE SEE Study Group

Purpose

To determine the prevalence of cataract and its association with sun exposure and other environmental risk factors in three different geographically diverse populations of India.

Design

Population based cross sectional study during 2010–2016

Participants

People aged ≥ 40 years residing in randomly sampled villages were enumerated (12021) and 9735 (81%) underwent ophthalmic evaluation from plains, hilly and coastal regions (3595, 3231, 2909 respectively)

Methods

A detailed questionnaire-based interview about outdoor activity in present, past and remote past, usage of sun protective measures, exposure to smoke, and detailed ophthalmic examination including assessment of uncorrected and best corrected visual acuity, measurement of intraocular pressure, slit lamp examination, lens opacities categorization using LOCS III and posterior segment evaluation was done. Lifetime effective sun exposure was calculated using Melbourne formula and expressed as quintiles. These were supplemented with physical environmental measurements.

Main outcome measures

Lifetime sun exposure hours, smoking, indoor kitchen smoke exposure and their association with cataract and subtypes. Prevalence of cataract calculated based on lens opacities or evidence of cataract surgery.

Results

Cataract was identified in 3231 (33.3%) participants. Prevalence of cataract in males (32.3%) and females (34.1%) was similar. Nuclear cataract was the commonest sub-type identified in 94.7% of affected eyes. Sun exposure had a significant association with cataract with odds ratio (OR) increasing from 1.6 (95% Confidence Intervals [CI]: 1.4, 1.9) in 3^rd quintile, to 2.6 (CI: 2.2, 3.1) in 4^th quintile and 9.4 (CI: 7.9, 11.2) in 5^th quintile (p<0.0001). Cataract also showed a significant association with smoking (OR: 1.4, CI: 1.2, 1.6) and indoor kitchen smoke exposure (OR: 1.2, CI: 1.0–1.4). Nuclear cataract showed a positive association with increasing sun exposure in 3^rd (β coefficient 0.5, CI:0.2–0.7), 4^th (β: 0.9, CI: 0.7–1.1) and 5^th (β: 2.1, CI:1.8–2.4) quintiles of sun exposure, smoking (β: 0.4, CI: 0.2–0.6) and indoor kitchen smoke exposure (β: 0.3, CI: 01–0.5) while cortical cataract showed a positive association with sun exposure only in 5^th quintile (β: 2.6, CI:1.0–4.2). Posterior subcapsular cataract was not associated with any of the risk factors.

Conclusion

Cataract is associated with increasing level of sun exposure, smoking and exposure to indoor kitchen smoke.

Cataract Services are Leaving Widows Behind: Examples from National Cross-Sectional Surveys in Nigeria and Sri Lanka

The Sustainable Development Goals aim to leave no one behind. We explored the hypothesis that women without a living spouse—including those who are widowed, divorced, separated, and never married—are a vulnerable group being left behind by cataract services. Using national cross-sectional blindness surveys from Nigeria (2005–2007; n = 13,591) and Sri Lanka (2012–2014; n = 5779) we categorized women and men by marital status (married/not-married) and place of residence (urban/rural) concurrently. For each of the eight subgroups we calculated cataract blindness, cataract surgical coverage (CSC), and effective cataract surgical coverage (eCSC). Not-married women, who were predominantly widows, experienced disproportionate cataract blindness—in Nigeria they were 19% of the population yet represented 56% of those with cataract blindness; in Sri Lanka they were 18% of the population and accounted for 54% of those with cataract blindness. Not-married rural women fared worst in access to services—in Nigeria their CSC of 25.2% (95% confidence interval, CI 17.8–33.8%) was far lower than the best-off subgroup (married urban men, CSC 80.0% 95% CI 56.3–94.3); in Sri Lanka they also lagged behind (CSC 68.5% 95% CI 56.6–78.9 compared to 100% in the best-off subgroup). Service quality was also comparably poor for rural not-married women—eCSC was 8.9% (95% CI 4.5–15.4) in Nigeria and 37.0% (95% CI 26.0–49.1) in Sri Lanka. Women who are not married are a vulnerable group who experience poor access to cataract services and high cataract blindness. To “leave no one behind”, multi-faceted strategies are needed to address their needs.

Cooking smoke exposure and respiratory symptoms among those responsible for household cooking: A study in Phitsanulok, Thailand

Cooking smoke affects the health of millions of people worldwide. In Thailand, however, information in regard to household cooking and the effects of cooking smoke is scarce. The objective of this descriptive study was to explore the risk factors and respiratory symptoms in household members responsible for household cooking. Participants from 1,134 rural households in Phitsanulok province, Thailand were randomly selected, using multistage sampling. Data on cooking activities and chronic respiratory problems, and symptoms identified in the past 30 days were collected using a modified questionnaire from the British Medical Research. Most of the participants were women aged over 40 years, who were responsible for food preparation in the household, and who usually cook with vegetable oil, using LPG gas, without a ventilation hood, according to the responses that we received, and our particular knowledge of household cooking facilities in rural areas in Thailand.

The most common chronic respiratory symptoms were runny nose (24.5% males, 21.8% females), dyspnea (26.1% females, 19.0% males) and chronic cough (9.2% females, 6.4% males). The most common respiratory symptoms experienced in the past 30 days were having a cold (28.3% females, 18.7% males), coughing (25.5% females, 21.1% ,males) and having sputum (13.0% females, 8.2% males). These symptoms were associated with tears while cooking, the number of hours present in the kitchen grilling food, and the number of stir-fried and deep-fried dishes prepared. This study demonstrated that cooking even with a clean fuel can quantitatively increase the risk of respiratory difficulties and symptoms. Since cooking is undertaken in every household in Thailand, this is a serious public health matter that demands more attention.

Investigating the Effects of Stove Emissions on Ocular and Cancer Cells

More than a third of the world’s population relies on solid fuels for cooking and heating, with major health consequences. Although solid fuel combustion emissions are known to increase the prevalence of illnesses such as chronic obstructive pulmonary disease and lung cancer, however, their effect on the eyes is underexplored. This study assesses the acute toxicity of solid fuel combustion emissions on healthy ocular cells and a cancer cell line. Three healthy ocular cell lines (corneal, lens, and retinal epithelial cells) and a cancer cell line (Chinese hamster ovary cells) were exposed to liquid and gas phase emissions from applewood and coal combustion. Following the exposure, real-time cell attachment behavior was monitored for at least 120 hours with electrical cell impedance spectroscopy. The viability of the cells, amount of apoptotic cells, and generation of reactive oxygen species (ROS) were quantified with MTT, ApoTox-Glo, and ROS-Glo H₂O₂ assays, respectively. The results showed that coal emissions compromised the viability of ocular cells more than applewood emissions. Interestingly, the cancer cells, although their viability was not compromised, generated 1.7 to 2.7 times more ROS than healthy cells. This acute exposure study provides compelling proof that biomass combustion emissions compromise the viability of ocular cells and increase ROS generation. The increased ROS generation was fatal for ocular cells, but it promoted the growth of cancer cells.

Air Pollution and Noncommunicable Diseases: A Review by the Forum of International Respiratory Societies' Environmental Committee, Part 2: Air Pollution and Organ Systems

Although air pollution is well known to be harmful to the lung and airways, it can also damage most other organ systems of the body. It is estimated that about 500,000 lung cancer deaths and 1.6 million COPD deaths can be attributed to air pollution, but air pollution may also account for 19% of all cardiovascular deaths and 21% of all stroke deaths. Air pollution has been linked to other malignancies, such as bladder cancer and childhood leukemia. Lung development in childhood is stymied with exposure to air pollutants, and poor lung development in children predicts lung impairment in adults. Air pollution is associated with reduced cognitive function and increased risk of dementia. Particulate matter in the air (particulate matter with an aerodynamic diameter < 2.5 μm) is associated with delayed psychomotor development and lower child intelligence. Studies link air pollution with diabetes mellitus prevalence, morbidity, and mortality. Pollution affects the immune system and is associated with allergic rhinitis, allergic sensitization, and autoimmunity. It is also associated with osteoporosis and bone fractures, conjunctivitis, dry eye disease, blepharitis, inflammatory bowel disease, increased intravascular coagulation, and decreased glomerular filtration rate. Atopic and urticarial skin disease, acne, and skin aging are linked to air pollution. Air pollution is controllable and, therefore, many of these adverse health effects can be prevented.

The toxicology of air pollution predicts its epidemiology

The epidemiologic investigation has successively delineated associations of air pollution exposure with non-malignant and malignant lung disease, cardiovascular disease, cerebrovascular disease, pregnancy outcomes, perinatal effects and other extra-pulmonary disease including diabetes. Defining these relationships between air pollution exposure and human health closely parallels results of an earlier epidemiologic investigation into cigarette smoking and environmental tobacco smoke (ETS), two other particle-related exposures. Humic-like substances (HULIS) have been identified as a chemical component common to cigarette smoke and air pollution particles. Toxicology studies provide evidence that a disruption of iron homeostasis with sequestration of host metal by HULIS is a fundamental mechanistic pathway through which biological effects are initiated by cigarette smoke and air pollution particles. As a result of a common chemical component and a shared mechanistic pathway, it should be possible to extrapolate from the epidemiology of cigarette smoking and ETS to predict associations of air pollution exposure with human disease, which are currently unrecognized. Accordingly, it is anticipated that the forthcoming epidemiologic investigation will demonstrate relationships of air pollution with COPD causation, peripheral vascular disease, hypertension, renal disease, digestive disease, loss of bone mass/risk of fractures, dental disease, eye disease, fertility problems, and extrapulmonary malignancies.