Solid fuel use for heating and risks of breast and cervical cancer mortality in China

Exposure to polycyclic aromatic hydrocarbons promotes the progression of low-grade cervical intraepithelial neoplasia: A population-based cohort study in China

Low-grade cervical intraepithelial neoplasia (CIN1) is an early stage of cervical cancer development. Previously, we reported that exposure to polycyclic aromatic hydrocarbons (PAHs) increases the risk of cervical precancerous lesions, especially in females with a high-risk human papillomavirus (HR-HPV) infection. However, the effects of PAHs on CIN1 progression remain unclear. A community-based prospective cohort study was conducted to evaluate the role of exposure to PAHs in the progression of CIN1. A total of 564 patients diagnosed with CIN1 were followed-up at 6, 12, and 24 months, post-diagnosis, to determine CIN1 reversion, persistence, and progression. Exposure to PAHs was determined by the urine 1-hydroxipayrene (1-OHP) level. Our results showed that the 1-OHP level was significantly higher in patients with CIN1 persistence/progression than in those with reversion (P < .05). High exposure to PAHs increased the risk of CIN1 persistence/progression, with hazard ratios (HR), 95% confidence intervals (CI) of (1.62, 1.24-2.67), (1.98, 1.42-2.75), and (2.37, 1.61-3.49) at 6, 12, and 24 months, post-diagnosis, respectively. The effect was enhanced with HR-HPV positivity, as determined at 6 (1.82, 1.24-2.67), 12 (3.02, 1.74-5.23), and 24 (2.51, 1.48-4.26) months, post-diagnosis. Moreover, the predictive value of exposure to PAHs for CIN1 persistence/progression was higher in HR-HPV-positive patients than in HR-HPV-negative patients. The results revealed that exposure to PAHs facilitated the malignant progression of CIN1 and hindered its reversal, particularly in patients with HR-HPV infection. Our findings provide novel insights into early prevention and intervention targeting the initiation and progression of cervical neoplasia.

From smoke to smiles: Quantifying the happiness benefits of household cooking energy transition

Existing studies that assess the impact of cooking with dirty solid fuels on human beings tend to underestimate the adverse impact on welfare. This paper aims to address this research gap by examining the happiness benefits of transitioning from solid fuel to cleaner alternatives. Using an extensive panel dataset from China, which includes 150,248 observations collected from 43,251 survey respondents interviewed between 2010 and 2018, this study employs various complementary methodologies, such as the fixed-effect model, propensity score matching, and time-varying difference-in-differences, to overcome challenges related to treatment selection bias and unobserved time-invariant heterogeneity. Further, life satisfaction approach is used to evaluate the economic benefits of cooking energy transition. Our findings indicate that switching from firewood to LPG/natural gas/gas can significantly enhance individual subjective well-being (SWB). Although the improvement brought about by electricity is slightly lower than that of LPG/natural gas/gas, it remains substantial. Notably, the positive effect is more pronounced among specific demographic groups, including females, rural residents, and low-income families. Moreover, these well-being improvements can manifest quickly and persist many years before any noticeable enhancements in physical health. This effect further amplifies over time. However, biogas shows no significant effect on SWB. These findings underscore the importance of clean fuels that contribute to increased happiness, as they are more likely to be consistently adopted. Finally, we estimate that the economic benefits of the well-being improvements resulting from the use of LPG/natural gas/gas and electricity range between $5.15 and $5.44 per day.

Household cooking fuel and gallbladder cancer risk: a multi-centre case-control study in India

PURPOSE

Gallbladder cancers (GBC), unique to certain geographical regions, are lethal digestive tract cancers, disproportionately affecting women, with limited information on risk factors.

METHODS

We evaluated the association between household cooking fuel and GBC risk in a hospital-based case-control study conducted in the North-East and East Indian states of Assam and Bihar. We explored the potential mediation by diet, fire-vents, 'daily exposure duration' and parity (among women). We recruited biopsy-confirmed GBC (n = 214) men and women aged 30-69 years between 2019 and 2021, and controls frequency-matched by age, sex and region (n = 166). Information about cooking fuel, lifestyle, personal and family history, female reproductive factors, socio-demographics, and anthropometrics was collected. We tested associations using multivariable logistic regression analyses.

RESULTS

All participants (73.4% women) were categorised based on predominant cooking fuel use. Group-1: LPG (Liquefied Petroleum Gas) users in the previous 20 years and above without concurrent biomass use (26.15%); Group-2: LPG users in the previous 20 years and above with concurrent secondary biomass use (15.9%); Group-3: Biomass users for ≥ 20 years (57.95%). Compared to group-1, accounting for confounders, GBC risk was higher in group-2 [OR: 2.02; 95% CI: 1.00-4.07] and group-3 [OR: 2.01; 95% CI: 1.08-3.73] (p-trend:0.020). These associations strengthened among women that attenuated with high daily consumption of fruits-vegetables but not with fire-vents, 'daily exposure duration' or parity.

CONCLUSION

Biomass burning was associated with a high-risk for GBC and should be considered as a modifiable risk factor for GBC. Clean cooking fuel can potentially mitigate, and a healthy diet can partially reduce the risk among women.

Anthropogenic emissions from coal-water slurry combustion: Influence of component composition and registration methods

The flue gas composition is often measured using a combination of techniques that differ in terms of both physical operation principle and type of output. Gas analyzers, FTIR spectrometers, and mass spectrometers are the most popular tools used for this purpose. In this research, we study the composition of the flue gas from the combustion of fuel slurries and dry composite fuels based on industrial and agricultural waste. It has been established that the use of slurry fuels makes the anthropogenic emissions 2-4 times lower than from the combustion of coal slime. For example, the CO₂ emissions from the combustion of dry coal slime were 2.5-3.7 times higher than from the combustion of slurry fuels. In addition, the combustion of slurry fuels made it possible to cut down the nitrogen oxide emissions by 1.3-1.5 times and sulfur oxide emissions by 1.3-2.7 times. A comparison of the results obtained using different measurement techniques has shown that differences between the CO and CO₂ content in the combustion products measured by a gas analyzer and an FTIR spectrometer did not exceed 20%. The use of FTIR spectroscopy provided new knowledge on the concentrations of hydrocarbons from the combustion of fuels based on promising industrial wastes.

Kitchen ventilation attenuated the associations of solid fuel use and long duration for cooking with the increased prevalence of normocytic anemia

Evidence on the potential risk factors of normocytic anemia, the most prevalent morphology subtype of anemia, was scarce to date. The purpose of this study is to investigate the association of cooking fuel use or daily cooking duration with normocytic anemia and further explore the modification effect of mechanical ventilation. Participants totaling 29,448 from the Henan Rural Cohort were included in this study. Normocytic anemia was defined by hemoglobin (based on the World Health Organization criteria) and mean corpuscular volume. Cooking-related data was collected by questionnaire, and the average daily cooking duration was calculated by the weekly cooking frequency and the cooking duration of each meal. Logistic regression models were employed to derive the combined and independent associations of cooking fuel type and daily cooking duration with normocytic anemia and the modification effect of ventilation. Compared with people who never cooked, both clean fuel and solid fuel users were significantly associated with increased prevalent normocytic anemia [OR (95% CI) = 1.196 (1.014, 1.411) and 1.335 (1.105, 1.614), respectively], and the effect estimates on normocytic anemia risk were 1.260 (1.043, 1.523), 1.320 (1.104, 1.578), and 1.310 (1.081, 1.587) in participants who daily cooked < 1 h/day, 1-2 h/day, and ≥ 2 h/day, respectively. These relationships were attenuated in subjects with mechanical ventilation (All P < 0.05). Cooking with solid fuel or for a long duration are independently associated with prevalent normocytic anemia in rural population, and mechanical ventilation could attenuate these associations. Future efforts to reduce the burden of anemia could target the universal use of ventilation and solid fuel use or cooking duration reduction.Clinical trial registration: The Henan Rural Cohort Study has been registered at Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699). Date of registration: 06 July, 2015. http://www.chictr.org.cn/showproj.aspx?proj=11375.

Biomass fuel usage for cooking and frailty among older adults in China: a population-based cohort study

Background

Although outdoor air pollution is reported to have a negative effect on frailty, evidence involving household air pollution is sparse.

Methods

A cohort study on older participants aged ≥65 years from the Chinese Longitudinal Healthy Longevity Survey was conducted between 2011/2012 and 2014. Household cooking fuel types were determined by self-reported questionaries, and were dichotomized into clean or biomass fuels. The frailty status was evaluated via a 46-item frailty index (FI) and the FRAIL scale, respectively. Frailty was identified if FI >0.21 or FRAIL score ≥3. Cox proportional hazards models were employed to examine the relationship between cooking fuels and incident frailty. And the effects of swapping cooking fuels on frailty risk were also explored.

Results

Among 4,643 participants (mean age at baseline 80.9 ± 9.6 years, 53.7% male) totaling 11,340 person-years, 923 (19.9%) incident frailty was identified using FI. Compared to clean fuels, cooking with biomass fuels was intricately linked to a 23% rise in frailty risk (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.06-1.43). A similar association was detected between biomass cooking fuels and frailty measured by the FRAIL scale (HR 1.24, 95% CI 1.04-1.50). Sensitive analyses supported the independent relationship between biomass fuels and frailty. Stratified analyses revealed that the frailty risk was higher among town residents (HR 1.44, 95% CI 1.13-1.84) and participants not exercising regularly (HR 1.35, 95% CI 1.11-1.64). In comparison with persistent biomass fuels usage, switching to clean fuels had a trend to reduce the frailty risk, and the opposite effect was observed when swapping from clean to biomass fuels.

Conclusion

Cooking with biomass fuels was associated with an increased frailty risk in older adults, especially amongst those living in town and those lacking regular exercise. More studies are needed to confirm our findings and to evaluate the potential benefits of reducing indoor biomass fuel usage.

Association between household air pollution and all-cause and cause-specific mortality: a systematic review and meta-analysis

Recently, a growing number of epidemiological studies have examined the relationship between household air pollution (HAP) and all-cause and cause-specific mortality. While the results were not entirely consistent, the current study followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) protocol to conduct a comprehensive review and meta-analysis. Data sources were PubMed, Web of Science, Embase, and Cochrane Library for studies published up to 12 May 2022. The pooled relative risks (RRs) with 95% confidence intervals (CI) were used to estimate the effect of household air pollution on all-cause and cause-special mortality. Then I square value (I²) was used to assess heterogeneity, and random-effects model was used as the pooling method. Seventeen studies were included in the quantitative analysis. Our results showed a significant association between household air pollution and increased risks of all-cause mortality (RR = 1.12, 95% CI = 1.06-1.19) and cardiovascular disease mortality (RR = 1.13, 95% CI = 1.04-1.24). Similarly, the associations between household air pollution and mortality from other specific causes (respiratory, ischemic heart disease, stroke, and total cancer) were positive, although they were not statistically significant. The study suggests that exposure to household air pollution increases the risk of all-cause mortality and cardiovascular disease mortality. In addition, our results found a trend of increased mortality from the respiratory system, ischemic heart disease, stroke, and total cancer, with household air pollution.

Indoor Solid Fuel Use and Non-Neoplastic Digestive System Diseases: A Population-Based Cohort Study Among Chinese Middle-Aged and Older Population

Objectives: We tended to explore the association of indoor air pollution (IAP) and non-neoplastic digestive system diseases (NNDSD) among the Chinese middle-aged and older population. Methods: From 2011 to 2018, we included 7884 NNDSD-free adults from the China Health and Retirement Longitudinal Study (CHARLS). Physician-diagnosed NNDSD was obtained by self-reported information at baseline and updated across follow-up surveys. We investigated the associations between baseline exposure of solid fuel use for cooking and/or heating and NNDSD diagnosed during follow-up through Cox proportional hazard models. Furthermore, we examined the relationship between cooking fuel switching and NNDSD diagnosed during follow-up. Results: Solid fuel use for cooking and/or heating was positively associated with NNDSD after adjusting for potential confounders. The risk of NNDSD among subjects who always use solid fuel for cooking (adjusted hazard ratio [aHR]: 1.42; 95% confidence interval [CI]: 1.09, 1.84) was higher than those with always clean fuels. Moreover, we found a lower NNDSD risk among participants who switched from solid to clean cooking fuel (aHR: 0.65; 95% CI: 0.49, 0.87) than those with always solid fuels. Conclusion: Our present study shows that indoor solid fuel use is a dependent risk factor for NNDSD. Moreover, switching to clean fuel may contribute to the prevention of digestive system illnesses.

Cooking or heating with solid fuels increased the all-cause mortality risk among mid-aged and elderly People in China

BACKGROUND

Our study aimed to explore the associations between solid fuels burning for either heating or cooking and all-cause mortality based on 2859 participants from the China Health and Retirement Longitudinal Study during 2011-2018.

METHODS

Logistic regression models were performed to estimate the risk for all-cause mortality between different types of fuels in the current longitudinal study. Furthermore, the combined impacts of applying solid fuels for both cooking and heating and the effect among those who switched types of fuels in cooking or heating during follow-up were also analyzed. Interaction and stratification analysis by covariables was applied further to explore the relationship between fuel burning and all-cause mortality.

RESULTS

After full-adjustment, usage of solid fuels was associated with higher all-cause mortality (for heating: OR = 1.93, 95% CI = 1.25, 3.00; for cooking: OR = 1.76, 95% CI = 1.10, 2.82). Using solid fuels for both cooking and heating (OR = 2.36; 95% CI, 1.38, 4.03) was associated with a higher risk of all-cause mortality, while using solid fuels with a single purpose was not (OR = 1.52; 95% CI, 0.90, 2.55). Protective tendencies were detected in switching solid to clean fuel for cooking (OR = 0.62; 95% CI, 0.32, 1.17) and heating (OR = 0.62; 95% CI, 0.35, 1.10).

CONCLUSION

Either cooking or heating with solid fuels increases the risk of all-cause mortality among Chinese mid-aged and aging people in the urban area of China.

Cervical and Endometrial Cancer Incidence in the Female Population from the Bryansk Region Living in Conditions of Chemical, Radioactive and Combined Environmental Contamination (2000-2020)

At the end of 36 years after the Chernobyl disaster, about 5 million people still live in the radioactively contaminated territories of Russia, Ukraine, and Belarus, and the density of radioactive contamination by Cesium-137 and Strontium-90 will remain radiologically significant for decades. We assessed cervical and endometrial cancer primary incidence (new cases) in the female population from the Bryansk region living in conditions of chemical, radioactive, and combined environmental contamination for 2000−2020. We found a significant increase in the long-term trend in the primary incidence of cervical and endometrial cancer in all the studied groups, regardless of the environmental conditions of residence (p < 0.00001). We did not find statistically significant differences in the incidence of cervical and endometrial cancer in women, regardless of the level of chemical, radioactive, and combined environmental contamination. However, women living in environmentally unfavorable areas (in total, in the territories of chemical, radioactive, and combined contamination) are statistically significantly more likely to develop endometrial cancer in terms of relative risk compared to environmentally safe (control) areas (RR 1.17 (1.08−1.27)). No such pattern was found for cervix cancer. It should be noted, since environmentally safe (control) areas have a certain level of contamination (albeit low), RR is underestimated.

Association between involuntary smoking and risk of cervical cancer in Chinese female never smokers: A prospective cohort study

Involuntary smoking was a major public health problem for women in China. Previous studies mainly focused on secondhand smoke (SHS), which referred to direct exposure to smoke from burning cigarettes. Little evidence existed about the relationship between thirdhand smoke (THS), the residual tobacco smoke remaining in the environment after tobacco had been smoked, and cervical cancer. The China Kadoorie Biobank (CKB) study recruited 0.3 million female participants from 10 areas across China during 2004-2008. After an 11.2-year median follow-up, we documented 1094 cervical cancer cases. Multivariable Cox regression yielded adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations of SHS and THS with cervical cancer incidence, respectively and jointly. Overall, 60.3% reported weekly SHS exposure, and 83.2% had been exposed to THS. Daily SHS exposure and THS exposure at the enrollment were associated with elevated risks of cervical cancer incidence, with adjusted HRs (95% CI) of 1.22 (1.06,1.42) and 1.24 (1.03,1.49), respectively. The longer the exposure duration, the higher the risks (P for trend = 0.006, 0.035, respectively). Compared with those who were neither exposed to SHS nor THS, those exposed to both SHS and THS had the highest risk, with adjusted HRs (95% CI) of 1.29 (1.05,1.58). Area of residence, breastfeeding duration and heating fuel types are potential effect modifiers. Among Chinese females, both SHS and THS were associated with higher risks of cervical cancer incidence, and a dose-response relationship was found between the exposure duration and cervical cancer risk. Our findings reinforce the need for proactive strategies for tobacco control, to protect women health.

Burden of lung cancer along with attributable risk factors in China from 1990 to 2019, and projections until 2030

OBJECTIVE

This study aimed to identify and project the epidemiological trends and the burden of lung cancer in China.

METHODS

We extracted incidence, mortality, disability-adjusted life-years (DALYs) and age-standardized rates of lung cancer in China, between 1990 and 2019, from the Global Burden of Disease Study (2019). The estimated annual percentage change (EAPC) was applied to quantify the trends of lung cancer burden. Furthermore, we used the Bayesian age-period-cohort model to project the incidence and mortality in the next decade.

RESULTS

From 1990 to 2019, the estimated national number of lung cancer incident cases increased by 224.0% to 832,920, deaths increased by 195.4% to 757,170 and DALYs increased by 146.1% to 17,128,580, respectively. Meanwhile, the ASIR, ASMR and ASDR showed an upward trend (EAPC of 1.33, 0.94 and 0.42, respectively). The ASIR and ASMR among males were about 2 times more than females, but the increase in ASIR in females (EAPC = 2.24) was more obvious than those in males (EAPC = 0.10) from 2020 to 2030. In China, smoking remained responsible for the highest burden of lung cancer, but the contribution of ambient particulate matter pollution to DALYs increased from 10.6% in 1990 to 22.5% in 2019 in total population. Moreover, we predicted that the number of deaths from lung cancer will increase by 42.7% in China by 2030.

CONCLUSION

In China, the burden of lung cancer has been increasing over the past three decades, which highlights more targeted intervention measures are needed to reduce the burden of lung cancer.

Global trends and age-specific incidence and mortality of cervical cancer from 1990 to 2019: an international comparative study based on the Global Burden of Disease

OBJECTIVE

To describe the trends of incidence and mortality of cervical cancer in different age groups and regions from 1990 to 2019.

DESIGN

An international comparative study based on the Global Burden of Disease (GBD) study estimates.

PARTICIPANTS

Data were publicly available and individuals were not involved.

METHODS

We collected detailed information on cervical cancer from the GBD study between 1990 and 2019. Average annual percentage changes (AAPCs) of age-standardised incidence and mortality rate (ASIR and ASMR) in cervical cancer, by age group and region, were calculated to quantify the temporal trends.

RESULTS

Globally, the absolute numbers of incident cases and deaths were increasing, with the most cervical cancer cases and deaths being reported in China, India and Brazil. Although the ASIR and ASMR have declined overall from 1990 to 2019, an increasing or stable trend was also observed in East Asia and Southern sub-Saharan Africa. Particularly, we found that the age-specific AAPC of incidence showed an increasing trend in the age group of 15-49 years globally, and the high Sociodemographic Index region increased the most.

CONCLUSIONS

Cervical cancer remains a concerning disease that affects women all over the world, although the ASIR and ASMR are decreasing. Efforts to control the younger trend and to reduce the disparity between regions are imminent.

Household Air Pollution From Solid Cooking Fuel Combustion and Female Breast Cancer

Background: Women bear a large share of disease burden caused by household air pollution due to their great involvement in domestic activities. Pollutant emissions are believed to vary by exposure patterns such as cooking and space heating. Little is known about the independent effect of solid cooking fuel combustion on breast cancer risk. We aimed to examine the association of indoor coal and wood combustion for cooking with breast cancer risk. Methods: During June 2004-July 2008, participants aged 30-79 from 10 diverse regions across China were enrolled in the China Kadoorie Biobank. Primary cooking fuel use information in up to three residences was self-reported at baseline. Multivariable logistic regression models yielded adjusted odds ratios (ORs) and 95% confidence intervals (CIs). Results: A total of 290,396 female participants aged 30-79 were included in the main analysis. Compared with long-term clean fuel users, the fully adjusted ORs were 2.07 (95%CI: 1.37-3.13) for long-term coal users, 1.12 (95% CI: 0.72-1.76) for long-term wood users, and 0.98 (95% CI: 0.55-1.74) for those who used mixed solid fuels to cook. Those who had switched from solid to clean fuels did not have an excess risk of breast cancer (OR: 0.88, 95%CI 0.71-1.10). Conclusion: Long-term solid fuel combustion for cooking may increase the risk of breast cancer. The strength of association is stronger among coal users than wood users. Targeted interventions are needed to accelerate the access to clean and affordable energy.

Effects of domestic solid fuel combustion emissions on the biomarkers of homemakers in rural areas of the Fenwei Plain, China

BACKGROUND

The health effects of heavy solid fuel use in winter in rural China are of concern. The effects of air pollution resulting from domestic solid fuel combustion in rural households on rural homemakers' biomarkers were revealed in this study.

METHODS

In total, 75 female homemakers from rural areas of Guanzhong Basin, the Fenwei Plain, People's Republic of China, were randomly selected and divided into three groups (biomass users, coal users, and nonusers of solid fuel user [control group]). The differences in biological indicators, including 8-hydrox-2'-deoxyguanosine (8-OHdG), interlukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) in urine samples as well as blood pressure (BP, including systolic BP [SBP] and diastolic BP [DBP]) and heart rate (HR) among the groups in winter and summer were investigated using statistical analysis.

RESULTS

IL-6, 8-OHdG, HR, SBP, and DBP were significantly higher in winter than in summer (P < 0.05) owing to the poor air quality resulted from the excessive use of solid fuels in winter. Significant seasonal differences in 8-OHdG were observed for both coal and biomass users. After the influence of confounders was removed, only IL-6 levels in the urine of solid fuel users were significantly higher than that of the control group.

CONCLUSIONS

IL-6 is a sensitive biomarker representing inflammatory responses to particulate matter emitted through household solid fuel combustion. Locally, excessive use of solid fuels in winter posed serious PM_2.5 pollution in this area and adverse effects on inflammatory biomarkers in these rural homemakers and induced DNA damage related to oxidative stress.

The potential co-benefits for health, economy and climate by substituting raw coal with waste cooking oil as a winter heating fuel in rural households of northern China

The toxic emissions from coal combustion associated with domestic winter heating requirements are an important public health issue. Waste cooking oil (WCO) holds promise as a means of reducing pollutant emissions thereby improving human health with the co-benefit of decreasing climate-forcing gas emissions by avoiding the combustion of mineral coal. With an annual production of ~2.17 Mt of WCO in Northern China, it could be used to meet the winter heating demand of ~3.25 million rural households, offsetting ~9.83 Mt of raw coal consumption. Through the adoption of coal-to-WCO shift in rural regions of 15 provinces, approximately 15.0%, 15.6%, 15.9% and 13.7%, respectively of CO, PM_2.5, SO₂ and NO_X emissions would be eliminated. It is estimated that such a change would remove the respective contributions of these pollutants to the premature deaths of respectively, 63,400, 29,300, 173,00 and 31,300 rural residents. Such a positive health impact on the labor cohort would reduce the loss of labor supply and work time, as well as producing billions of RMB in economic benefits. WCO-based heating technology has the same effect on the reduction of GWC₁₀₀ value as other modern energy carriers while also being cheaper and sustainable, long term. Reducing household emissions by substituting raw coal with green energy is a vital strategy to support pathways for sustainable environment design. The results of this work for the coal-to-WCO shift can reinforce the support for coal phase-out in China.