Research progress and management strategies of fungal diseases in Camellia oleifera

Camellia oleifera Abel, a woody oil plant, that is endemic to China. Tea oil, also referred to as “oriental olive oil,” is a superior quality plant-based cooking oil. The production of tea oil accounts for 8% of the total edible vegetable oil production in the country. Since 2022, the annual output value of C. oleifera industry has exceeded 100 billion yuan, making it one of the major economic contributors to China’s rural revitalization development strategy. In recent years, demand and production have grown in parallel. However, this has led to an increase in the incidence levels of pest and diseases. Pests and diseases significantly reduce the quality and yield of C. oleifera. C. oleifera diseases are mainly caused by pathogenic fungi. C. oleifera anthracnose, soft rot, leaf spot, coal stain, leaf gall disease, and root rot are the most important fungal diseases affecting the C. oleifera industry. However, the same disease may be caused by different pathogenic fungi. C. oleifera can be found in half of China and is found in several climatic zones. The geographical distribution of woody plant diseases is consistent with the distribution of the tree species and the ecology of the range, which also results in a highly complex distribution of fungal diseases of C. oleifera. The management of fungal diseases in C. oleifera is extremely challenging due to the variety of pathogenic fungal species, multiple routes of transmission, the lack of resistant plants, and the environmental safety of chemical measures. The optimal strategy for addressing fungal diseases in C. oleifera is to develop and apply an integrated disease management plan. This review provides a brief overview of the pathogenic species, pathogenesis, pathogenesis, geographical distribution, current management strategies, and potentially new methods of C. oleifera fungal diseases, to provide direction for the development of comprehensive management measures for C. oleifera fungal diseases in the future

Coal Use, Stove Improvement, and Adult Pneumonia Mortality in Xuanwei, China: A Retrospective Cohort Study

Background: In Xuanwei County, China, unvented indoor coal burning is strongly associated with increased risk of lung cancer and chronic obstructive pulmonary disease. However, the impact of coal burning and stove improvement on risk of pneumonia is not clear. Methods: We conducted a retrospective cohort study among all farmers born 1917 through 1951 and living in Xuanwei as of 1 January 1976. The analysis included a total of 42,422 cohort members. Follow-up identified all deaths in the cohort from 1976 through 1996. Ages at entry into and at exit from follow-up ranged from 24 to 59 years and from 25 to 80 years, respectively. The record search detected 225 deaths from pneumonia, and 32,332 (76%) were alive as of 31 December 1996. We constructed multivariable Cox models (time variable = age) to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Results: Use of coal, especially smokeless coal, was positively associated with pneumonia mortality. Annual tonnage and lifetime duration of smoky and smokeless coal use were positively associated with pneumonia mortality. Stove improvement was associated with a 50% reduction in pneumonia deaths (smoky coal users: HR, 0.521; 95% CI, 0.340-0.798; smokeless coal users: HR, 0.449; 95% CI, 0.215-0.937). Conclusions: Our analysis is the first to suggest that indoor air pollution from unvented coal burning is an important risk factor for pneumonia death in adults and that improving ventilation by installing a chimney is an effective measure to decrease it.published_or_final_versio

Increased Mortality Associated with Well-Water Arsenic Exposure in Inner Mongolia, China

We conducted a retrospective mortality study in an Inner Mongolian village exposed to well water contaminated by arsenic since the 1980s. Deaths occurring between January 1, 1997 and December 1, 2004 were classified according to underlying cause and water samples from household wells were tested for total arsenic. Heart disease mortality was associated with arsenic exposure, and the association strengthened with time exposed to the water source. Cancer mortality and all-cause mortality were associated with well-water arsenic exposure among those exposed 10–20 years. This is the first study to document increased arsenic-associated mortality in the Bayingnormen region of Inner Mongolia

Well Water Arsenic Exposure, Arsenic Induced Skin-Lesions and Self-Reported Morbidity in Inner Mongolia

Residents of the Bayingnormen region of Inner Mongolia have been exposed to arsenic-contaminated well water for over 20 years, but relatively few studies have investigated health effects in this region. We surveyed one village to document exposure to arsenic and assess the prevalence of arsenic-associated skin lesions and self-reported morbidity. Five-percent (632) of the 12,334 residents surveyed had skin lesions characteristics of arsenic exposure. Skin lesions were strongly associated with well water arsenic and there was an elevated prevalence among residents with water arsenic exposures as low as 5 μg/L-10 μg/L. The presence of skin lesions was also associated with self-reported cardiovascular disease

Improvement in household stoves and risk of chronic obstructive pulmonary disease in Xuanwei, China: retrospective cohort study

Objective To test whether improvement in household coal stoves affected the incidence of chronic obstructive pulmonary disease (COPD) in Xuanwei County, China. Design Retrospective cohort study (follow-up 1976-92) comparing incidence of COPD between groups with and without chimneys. Participants 20 453 people born into homes with unvented coal stoves;16 606 (81.2%) subsequently changed to stoves with chimneys. Intervention Installation of a chimney in households in which unvented stoves had been used previously. Results Installation of a chimney was associated with distinct reduction in the incidence of COPD. Compared with people who did not have chimneys, the Cox-modelled risk ratio (relative risk) was 0.58 (95% confidence interval 0.49 to 0.70, P < 0.001) in men and 0.75 (0.62 to 0.92, P = 0.005) in women. Modelled risk ratios were robust to different Cox model specifications. Relative risks decreased with time since stove improvement. In both sexes, the reduction in risk became unequivocal about 10 years after stove improvement. Conclusions In Xuanwei, incidence of COPD decreased markedly after household coal stoves were improved

Household stove improvement and risk of lung cancer in Xuanwei, China

Background: Lung cancer rates in rural Xuanwei County, Yunnan Province, are among the highest in China. Residents traditionally burned "smoky" coal in unvented indoor firepits that generated very high levels of air pollution. Since the 1970s, most residents have changed from firepits to stoves with chimneys. This study assessed whether lung cancer incidence decreased after this stove improvement. Methods: A cohort of 21232 farmers, born from 1917 through 1951, was followed retrospectively from 1976 through 1992. All subjects were users of smoky coal who had been born into homes with unvented firepits. During their lifetime, 17 184 subjects (80.9%) changed permanently to stoves with chimneys. A hospital record search detected 1384 cases of lung cancer (6.5%) during follow-up. Associations of stove improvement with lung cancer incidence were analyzed with product-limit plots and multivariable Cox models. In 1995, indoor concentrations of airborne particles and benzo[a]pyrene were compared in Xuanwei homes during smoky coal burning in stoves with chimneys and in unvented stoves or firepits. Results: A long-term reduction in lung cancer incidence was noted after stove improvement. In Cox models, risk ratios (RRs) for lung cancer after stove improvement were 0.59 (95% confidence interval [CI] = 0.49 to 0.71) in men and 0.54 (95% CI = 0.44 to 0.65) in women (for both, P<.001). Incidence reduction became unequivocal about 10 years after stove improvement. Levels of indoor air pollution during burning with chimneys were less than 35% of levels during unvented burning. Conclusion: Changing from unvented to vented stoves appears to benefit the health of people in China and may do so in other developing countries as well.link_to_subscribed_fulltex

Molecular Epidemiology Study in Xuanwei: the Relationship among Coal Type, Genotype and Lung Cancer Risk

Background and objective It has been proven that the lung cancer mortality rate in Xuanwei County, China was among the highest in the country and has been associated with exposure to indoor smoky coal emissions that contain high levels of polycyclic aromatic hydrocarbons. This risk may be modified by variation in genetic polymorphisms and coal subtypes. Our objective was to use molecular epidemiological techniques to investigate the relationship among genetic polymorphisms, coal subtype and lung cancer risk in Xuanwei County. Methods On the basis of two population-based case-control studies in residents of Xuanwei County, China, questionnaires covering demographic information, smoking history, family and personal medical history, and information on other variables were administered and buccal cells and sputum samples were collected separately from each subject enrolled to extract DNA. GST superfamily, AKR1C3 superfamily, OGG1 superfamily and other genotype were scanned by useing PCR method. ORs and 95%CIs were used to estimate the association between genotypes, coal subtypes and lung cancer risk factors by conditional Logistic regression using Statistical Analysis Software. Results Compared with subjects who using smokeless coal or wood, smoky coal use was statistically significantly associated with lung cancer risk (OR=7.7, 95%CI: 4.5-13.3). There was marked heterogeneity in risk estimates for specific subtypes of smoky coal. Estimates were highest for coal from the Laibin (OR=24.8), Longtan (OR=11.6) and Baoshan (OR=6.0) coal types, and lower for coal from other types; the risk within the same subtype of coal in male and female were similar. The GSTM1-null genotype, the AKR1C3 (Ex1-70C>G), OGG1 (Ex6-315C>G) genotypes were closely associated with increased risk of lung cancer in Xuanwei County, and their odds ratios (95%CI) were 2.3 (1.3-4.2), 1.8 (1.0-3.5) and 1.9 (1.1-3.3), respectively. Compared to subjects who with GSTM1-positive and used less than 130 tons of smoky coal during their lifetime, higher risks were closely associated with GSTM1-null and heavier users (≥130 tons), with the OR was 4.9 (95%CI: 1.3-18.2) and 2.7 (95%CI: 1.0-7.4) for female and male, respectively. However, higher risks were only found within female for AKR1C3 (Ex1-70C>G) and OGG1 (Ex6-315C>G), with OR (95%CI)=12.9 (2.2-107.8) and 5.7 (1.1-34.2), respectively. Conclusion Lung cancer risks varied among coal subtypes; however, risks were similar between men and women exposed to the same type of coal. The GSTM1-null genotype may enhance susceptibility to air pollution from indoor smoky coal combustion emissions. AKR1C3 and OGG1 genotypes were significantly associated with higher risk of lung cancer, especially among heavily exposed women

Effect of chimneys on indoor air concentrations of PM10 and benzo[a]pyrene in Xuan Wei, China

This paper reports the effect of chimneys in reducing indoor air pollution in a lung cancer epidemic area of rural China. Household indoor air pollution concentrations were measured during unvented burning (chimneys blocked) and vented burning (chimneys open) of bituminous coal in Xuan Wei, China. Concentrations of particulate matter with an aerodynamic diameter of 10 μm or less (PM10) and of benzo[a]pyrene (BaP) were measured in 43 homes during normal activities. The use of chimneys led to significant decreases in indoor air concentrations of particulate matter with an aerodynamic diameter of 10 μm or less (PM10) by 66% and of benzo[a]pyrene (BaP) by 84%. The average BaP content of PM10 also decreased by 55% with the installation of a chimney. The reduction of indoor pollution levels by the installation of a chimney supports the epidemiology findings on the health benefits of stove improvement. However, even in the presence of a chimney, the indoor air concentrations for both PM10 and BaP still exceeded the indoor air quality standards of China. Movement up the energy ladder to cleaner liquid or gaseous fuels is probably the only sustainable indoor air pollution control measure. © 2009 Elsevier Ltd.link_to_subscribed_fulltex