Expanded Damage Function of Stratospheric Ozone Depletion to Cover Major Endpoints Regarding Life Cycle Impact Assessment (12 pp)

Background Stratospheric ozone depletion is one of the important environmental issues for LCIA. The National LCA Project of Japan has developed a framework of LCIA since 1998, which tackles the issue employing an endpoint approach. Although the basic components were available in 2000, it was required that the target endpoints should be expanded in particular. Objective This study aimed at expanding the scope of damage function of ozone depletion in the LCIA framework of LIME. Damage function gives potential and quantitative damage for each endpoint per unit emission of ODS. Methods Marginal damage due to the unit emission of ODS was calculated for 13 substances for which quantitative information was available as follows: (1) the increase of UVB radiation at the earth's surface per unit emission of ODS was estimated, (2) the increase of potential damage per unit increase of UVB radiation was estimated, (3) the increase of potential damage per unit emission of ODS was determined by connecting the two relationships, and (4) correcting by the atmospheric lifetime of ODS, so that the damage function was then obtained. For other ODSs regulated by the Montreal Protocol, their damage functions were estimated by multiplying the ratio of ODP compared to the corresponding reference substance by the damage function of this reference substance. Results and Discussion The damage function of ozone depletion included the following endpoints: skin cancer and cataract for human health, crop production and timber production for social assets, and terrestrial NPP and aquatic NPP for primary productivity. And damage factors for each safeguard subject were also obtained. Conclusion The damage function of ozone depletion could cover all ODSs regulated by the Montreal Protocol and also cover important endpoints. Uncertainty of damage function is also an important point to be elucidated. Preliminary studies of uncertainty analysis have begun for the damage function of ozone depletion. However, further analysis is required to comprehensively evaluate the uncertainty of the damage function. - Abbreviations: BCC-Basal Cell Carcinoma; CFC-Chlorofluorocarbon; DALY-Disability Adjusted Life Years; DF-Damage Factor; DI-Damage Indicator; EESC-Equivalent Effective Stratospheric Chlorine; HBFC-Hydrobromofluorocarbon; HCFC-Hydrochlorofluorocarbon; LCA-Life Cycle Assessment; LCIA-Life Cycle Impact Assessment; LIME-Life-cycle Impact assessment Method based on Endpoint modeling; MM-malignant melanoma; NPP-Net Primary Production; ODP-Ozone Depletion Potential; ODS-Ozone Depleting Substance; SCC-Squamous Cell Carcinoma; TCL-Tropospheric Chlorine Loading; UVB-Ultraviolet B; YLD-Years of Life Disabled; YLL-Years of Life Lost.     

Managing Global Atmospheric Change: A U.S. Policy Perspective

There are several air pollution issues that concern the international community at the regional and global level, including acid deposition, heavy metals, persistent organic pollutants, stratospheric ozone depletion, and climate change. Governments at the regional and global levels have entered into various agreements in an effort to deal with these problems. This paper deals with two major global atmospheric change issues: stratospheric ozone depletion and climate change. The focus is on the policy responses of the United States to these global issues. The United States has signed and ratified international agreements to deal with both problems. The Vienna Convention and the Montreal Protocol on Substances that Deplete the Ozone Layer have led to an effort in both developed and developing countries to phase out ozone depleting substances. The United Nations Framework Convention on Climate Change (UNFCCC) has been signed and ratified by over 180 countries. The UNFCC contained no binding targets and timetables for emissions reductions. The Kyoto Protocol (1997) to the UNFCCC did contain targets and timetables for reductions of greenhouse gases on the part of developed countries. The United States has signed but not ratified the Kyoto Protocol. The United States has experienced some movement to reduce greenhouse gas emissions on the part of various levels of government as well as the private sector. The policy process is constantly informed by scientific research. In the case of stratospheric ozone depletion and climate change, much of this work is carried out under the auspices of international scientific panels. From a policy perspective, there is a great deal of interest in the use of indicators for assessing the scope and magnitude of these problems, both for fashioning policy responses as well as assessing the impact of adopted programs to reduce ozone depleting substances, and potentially, greenhouse gases. This paper will discuss some of the indicators used for stratospheric ozone depletion and climate change.     

Acute sun damage and photoprotective responses in whales

Rising levels of ultraviolet radiation (UVR) secondary to ozone depletion are an issue of concern for public health. Skin cancers and intraepidermal dysplasia are increasingly observed in individuals that undergo chronic or excessive sun exposure. Such alterations of skin integrity and function are well established for humans and laboratory animals, but remain unexplored for mammalian wildlife. However, effects are unlikely to be negligible, particularly for species such as whales, whose anatomical or life-history traits force them to experience continuous sun exposure. We conducted photographic and histological surveys of three seasonally sympatric whale species to investigate sunburn and photoprotection. We find that lesions commonly associated with acute severe sun damage in humans are widespread and that individuals with fewer melanocytes have more lesions and less apoptotic cells. This suggests that the pathways used to limit and resolve UVR-induced damage in humans are shared by whales and that darker pigmentation is advantageous to them. Furthermore, lesions increased significantly in time, as would be expected under increasing UV irradiance. Apoptosis and melanocyte proliferation mirror this trend, suggesting that whales are capable of quick photoprotective responses. We conclude that the thinning ozone layer may pose a risk to the health of whales and other vulnerable wildlife.     

Value Choices in Life Cycle Impact Assessment of Stressors Causing Human Health Damage

This article investigates how value choices in life cycle impact assessment can influence characterization factors (CFs) for human health (expressed as disability‐adjusted life years [DALYs]). The Cultural Theory is used to define sets of value choices in the calculation of CFs, reflecting the individualist, hierarchist, and egalitarian perspectives. CFs were calculated for interventions related to the following impact categories: water scarcity, tropospheric ozone formation, particulate matter formation, human toxicity, ionizing radiation, stratospheric ozone depletion, and climate change. With the Cultural Theory as a framework, we show that individualist, hierarchist, and egalitarian perspectives can lead to CFs that vary up to six orders of magnitude. For persistent substances, the choice in time horizon explains the differences among perspectives, whereas for nonpersistent substances, the choice in age weighting and discount rate of DALY and the type of effects or exposure routes account for differences in CFs. The calculated global impact varies by two orders of magnitude, depending on the perspective selected, and derives mainly from particulate matter formation and water scarcity for the individualist perspective and from climate change for the egalitarian perspective. Our results stress the importance of dealing with value choices in life cycle impact assessment and suggest further research for analyzing the practical consequences for life cycle assessment results.     

Climate change and health with an emphasis on interactions with ultraviolet radiation: a review

Climate change is increasingly recognized as a major risk to human health, and health concerns are assuming more importance in international debates on mitigation and adaptation strategies. Health consequences of climate change will occur through direct and indirect routes, and as a result of interactions with other environmental exposures. Heatwaves will become more common and are associated with higher mortality particularly in the elderly and those with pre‐existing cardiovascular and respiratory illnesses. Warmer ambient temperatures will result in more dehydration episodes and increased risks of renal disease and, through effects on pollen seasons, there may be an increase in allergic disease such as asthma and hayfever. Other adverse effects including on air quality, food safety and security and an expanding distribution of some infectious diseases, including vector‐borne diseases, are postulated. A related but separate environmental exposure is that of ultraviolet radiation (UVR). Interactions between climate change and stratospheric ozone (and the causes of ozone depletion) will cause changes to levels of ambient UVR in the future and warmer temperatures are likely to change sun exposure behaviour. Co‐occurring effects on aquatic and terrestrial ecosystems have potential consequences for food safety, quality and supply. Climate change‐related exposures are likely to affect the incidence and distribution of diseases usually considered as caused by UVR exposure; and changes in UVR exposure will modulate the climate change effects on human health. For example, in some regions warmer temperatures due to climate change will encourage more outdoor behaviour, with likely consequences for increasing skin cancer incidence. Although many of the health outcomes of both climate change and the interaction of climate change and UVR exposure are somewhat speculative, there are risks to over‐ or under‐estimations of health risks if synergistic and antagonistic effects of co‐occurring environmental changes are not considered.     

Changes in tropospheric composition and air quality due to stratospheric ozone depletion and climate change.

It is well-understood that reductions in air quality play a significant role in both environmental and human health. Interactions between ozone depletion and global climate change will significantly alter atmospheric chemistry which, in turn, will cause changes in concentrations of natural and human-made gases and aerosols. Models predict that tropospheric ozone near the surface will increase globally by up to 10 to 30 ppbv (33 to 100% increase) during the period 2000 to 2100. With the increase in the amount of the stratospheric ozone, increased transport from the stratosphere to the troposphere will result in different responses in polluted and unpolluted areas. In contrast, global changes in tropospheric hydroxyl radical (OH) are not predicted to be large, except where influenced by the presence of oxidizable organic matter, such as from large-scale forest fires. Recent measurements in a relatively clean location over 5 years showed that OH concentrations can be predicted by the intensity of solar ultraviolet radiation. If this relationship is confirmed by further observations, this approach could be used to simplify assessments of air quality. Analysis of surface-level ozone observations in Antarctica suggests that there has been a significant change in the chemistry of the boundary layer of the atmosphere in this region as a result of stratospheric ozone depletion. The oxidation potential of the Antarctic boundary layer is estimated to be greater now than before the development of the ozone hole. Recent modeling studies have suggested that iodine and iodine-containing substances from natural sources, such as the ocean, may increase stratospheric ozone depletion significantly in polar regions during spring. Given the uncertainty of the fate of iodine in the stratosphere, the results may also be relevant for stratospheric ozone depletion and measurements of the influence of these substances on ozone depletion should be considered in the future. In agreement with known usage and atmospheric loss processes, tropospheric concentrations of HFC-134a, the main human-made source of trifluoroacetic acid (TFA), is increasing rapidly. As HFC-134a is a potent greenhouse gas, this increasing concentration has implications for climate change. However, the risks to humans and the environment from substances, such as TFA, produced by atmospheric degradation of hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) are considered minimal. Perfluoropolyethers, commonly used as industrial heat transfer fluids and proposed as chlorohydrofluorocarbon (CHFC) substitutes, show great stability to chemical degradation in the atmosphere. These substances have been suggested as substitutes for CHFCs but, as they are very persistent in the atmosphere, they may be important contributors to global warming. It is not known whether these substances will contribute significantly to global warming and its interaction with ozone depletion but they should be considered for further evaluation.     

Global increases in ultraviolet B radiation: potential impacts on amphibian development and metamorphosis

Levels of ultraviolet B radiation (UVBR) reaching the Earth's surface have increased since the 1970s as a result of stratospheric ozone depletion caused by the emission of ozone-depleting substances (ODSs) such as chlorofluorocarbons. Despite international agreements to phase out harmful ODSs, these substances are persistent, and even under the most optimistic scenarios, stratospheric ozone levels will not return to pre-1980 levels for several decades. Furthermore, climate change may enhance chemical stratospheric ozone depletion. Global phenomena such as climate change, ozone depletion, and acidification of aquatic ecosystems interact to modify dissolved organic carbon levels in aquatic systems, thereby increasing the penetration of UVBR. Since amphibians inhabit both aquatic and terrestrial habitats and have unshelled eggs and permeable skin, they are vulnerable to changes in environmental conditions and habitat quality. Increased exposure of amphibians to UVBR can produce lethal and sublethal effects, especially in individuals that do not possess adequate defense mechanisms to protect themselves. In this article, we discuss worldwide increases in UVBR and the adverse effects of UVBR exposure on amphibians. Specifically, studies on the effects of UVBR on amphibian development and metamorphosis are summarized, and possible mechanisms of thyroid system disruption caused by UVBR exposure are considered.     

Climate change and human skin cancer.

As part of an inventory of potential interactions between effects of ozone depletion and climate change, a possible effect of ambient temperature on sun-induced skin cancers was suggested. Mouse experiments had shown that increased room temperature enhanced ultraviolet (UV) radiation-induced carcinogenesis; the effective UV dose was increased by 3-7% per degrees C. The present investigation was aimed at studying a possible temperature effect on human skin cancer. Existing data on the incidence of human skin cancer were analyzed, as available from two special surveys of non-melanoma skin cancer in the United States. The incidence of non-melanoma skin cancer in the ten regions surveyed not only correlated significantly with the ambient UV dose but also with the average daily maximum temperature in summer. For squamous cell carcinoma the incidence was higher by 5.5% (SE 1.6%) per degrees C and for basal cell carcinoma by 2.9% (SE 1.4%) per degrees C. These values correspond to an increase of the effective UV dose by about 2% per degrees C. Although the precise nature of this correlation with temperature requires further studies, it can be concluded that the temperature rises coming with climate change can indeed amplify the induction of non-melanoma skin cancers by UV radiation in human populations.     

Was skin cancer a selective force for black pigmentation in early hominin evolution?

Melanin provides a crucial filter for solar UV radiation and its genetically determined variation influences both skin pigmentation and risk of cancer. Genetic evidence suggests that the acquisition of a highly stable melanocortin 1 receptor allele promoting black pigmentation arose around the time of savannah colonization by hominins at some 1–2 Ma. The adaptive significance of dark skin is generally believed to be protection from UV damage but the pathologies that might have had a deleterious impact on survival and/or reproductive fitness, though much debated, are uncertain. Here, I suggest that data on age-associated cancer incidence and lethality in albinos living at low latitudes in both Africa and Central America support the contention that skin cancer could have provided a potent selective force for the emergence of black skin in early hominins.     

Comment on "the effects on human health from stratospheric ozone depletion and its interactions with climate change" by M. Norval, A. P. Cullen, F. R. de Gruijl, J. Longstreth, Y. Takizawa, R. M. Lucas, F. P. Noonan and J. C. van der Leun, Photochem. Photobiol. Sci., 2007, 6, 232.

An increase in solar ultraviolet-B (UVB) radiation reaching the earth's surface is an important consequence of stratospheric ozone depletion. UVB has important effects on human health, both beneficial and harmful. Recent research has found that solar UVB reduces the risk of over 20 types of cancer, respiratory diseases caused by viruses, autoimmune diseases, and, likely, several other diseases, in addition to the well-known effects on bone diseases. On the other hand, solar UVB is an important risk factor for non-melanoma skin cancer and cataracts. Human epidemiological studies have provided evidence that solar UVA may be a more important risk factor for melanoma than UVB. If this result is correct, melanoma risk is not related to ozone depletion. We consider the net effect of solar UVB on human health to be beneficial at or near current levels.     

冬麦田臭氧干沉降过程的观测

地表臭氧作为近地层最主要的大气污染物之一,其不断上升的浓度及其对粮食作物的影响受到越来越多的关注.本研究利用微气象学观测方法,探明自然条件下冬麦田的臭氧沉降过程,分析了影响臭氧沉降过程的环境因子.结果表明: 观测期内(小麦生长旺期)臭氧通量均值为-0.35 μg·m^-2·s^-1(负号表示沉降方向指向地面),臭氧沉降平均速率为0.55 cm·s^-1,空气动力学阻力均值为30 s·m^-1,粘性副层阻力均值为257 s·m^-1,冠层阻力均值为163 s·m^-1,且均存在明显的日变化趋势.臭氧沉降阻力大小受摩擦速度、太阳辐射强度、温度和相对湿度等因素的影响.     

Not just about sunburn – the ozone hole's profound effect on climate has significant implications for Southern Hemisphere ecosystems

Climate scientists have concluded that stratospheric ozone depletion has been a major driver of Southern Hemisphere climate processes since about 1980. The implications of these observed and modelled changes in climate are likely to be far more pervasive for both terrestrial and marine ecosystems than the increase in ultraviolet‐B radiation due to ozone depletion; however, they have been largely overlooked in the biological literature. Here, we synthesize the current understanding of how ozone depletion has impacted Southern Hemisphere climate and highlight the relatively few documented impacts on terrestrial and marine ecosystems. Reviewing the climate literature, we present examples of how ozone depletion changes atmospheric and oceanic circulation, with an emphasis on how these alterations in the physical climate system affect Southern Hemisphere weather, especially over the summer season (December–February). These potentially include increased incidence of extreme events, resulting in costly floods, drought, wildfires and serious environmental damage. The ecosystem impacts documented so far include changes to growth rates of South American and New Zealand trees, decreased growth of Antarctic mosses and changing biodiversity in Antarctic lakes. The objective of this synthesis was to stimulate the ecological community to look beyond ultraviolet‐B radiation when considering the impacts of ozone depletion. Such widespread changes in Southern Hemisphere climate are likely to have had as much or more impact on natural ecosystems and food production over the past few decades, than the increased ultraviolet radiation due to ozone depletion.     

A life history perspective on skin cancer and the evolution of skin pigmentation

The ancestral state of human skin pigmentation evolved in response to high ultraviolet radiation (UVR) stress. Some argue that pigmentation evolved to limit folate photolysis, therein limiting neural tube defects. Pigmentation also protects against sunburn which decreases the efficiency of sweating and potentiates skin infection. Pigmentation increases the efficacy of skin as a barrier to infection. Skin cancer has been rejected or minimized as a selective pressure because it is believed to have little or no effect on mortality during reproductive years. This argument ignores evidence of human longevity as a derived life history trait and the adaptive value of investment in offspring and kin, particularly during the post‐reproductive lifespan. Opponents argue that lifespan in prehistoric hunter‐gatherers was too short to be relevant to the evolution of skin pigmentation. This argument is flawed in that it relies on estimates of longevity at birth rather than adolescence. When appropriate estimates are used, it is clear that human longevity has a deep evolutionary history. We use a life history perspective to demonstrate the value of skin pigmentation as an adaptation to skin cancer with the following points: UVR exposure increases dysregulation of gene expression in skin cells leading to immortal cell lines; cutaneous malignant melanoma (CMM) affects individuals throughout reproductive years; and lifespan was longer than has previously been acknowledged, providing the opportunity for kin selection. This hypothesis is not at odds with the folate or barrier hypotheses. We stress that the evolution of skin pigmentation is complex and is an ongoing process. Am J Phys Anthropol 153:1–8, 2014. © 2013 Wiley Periodicals, Inc.     

Sensitivity Analysis of U.S. EPA's Estimates of Skin Cancer Risk from Inorganic Arsenic in Drinking Water

The current U.S. Environmental Protection Agency's (USEPA's) risk analysis on the Integrated Risk Information System (IRIS) for arsenic in drinking water is based on an epidemiological study of skin cancer in Taiwan. Assumptions used in the USEPA application of the multistage-Weibull model for risk estimation were varied to assess the effect on predicted risk of skin cancer to the U.S. population at arsenic concentrations of 1 to 50?µg/L in drinking water. Among the assumptions tested, the only notable change in risk estimates was a reduction when the arsenic concentration used as representative for Taiwan villages in the low range (<300?µg/L) was increased to the 75th percentile (245?µg/L) in place of the mean used in the USEPA analysis (170?µg/L), but the representative value for Taiwan villages in the high range (≥600?µg/L) was not increased simultaneously to the 75th percentile. Additionally, a simulation study was conducted using records of arsenic measurements in wells from the same period and region of Taiwan as the original study. The exposure-response curve estimated from 60 villages (60 data points) differed only marginally from the outcome when data were summarized into four data points (as in the USEPA skin cancer analysis). Briefly discussed are differences between the study area of Taiwan and the U.S. in nutritional status and consumption of inorganic arsenic in food that might bias predicted U.S. skin cancer risks.     

Defining hybrid poplar (Populus deltoides × Populus trichocarpa) tolerance to ozone: identifying key parameters

This study examined whether two genotypes of hybrid poplar ( Populus deltoides  ×  Populus trichocarpa ), previously classified as ozone tolerant and ozone sensitive, had differing physiological and biochemical responses when fumigated with 120 nL L⁻¹ ozone for 6 h per day for eight consecutive days. Isoprene emission rate, ozone uptake and a number of physiological and biochemical parameters were investigated before, during and after fumigation with ozone. Previous studies have shown that isoprene protects plants against oxidative stress. Therefore, it was hypothesized that these two genotypes would differ in either their basal isoprene emission rates or in the response of isoprene to fumigation by ozone.
Our results showed that the basal emission rates of isoprene, physiological responses and ozone uptake rates were all similar. However, significant differences were found in visible damage, carotenoids, hydrogen peroxide (H₂O₂), thiobarbituric acid reactions (TBARS) and post-fumigation isoprene emission rates. It is shown that, although the classification of ozone tolerance or sensitivity had been previously clearly and carefully defined using one particular set of parameters, assessment of other key variables does not necessarily lead to the same conclusions. Thus, it may be necessary to reconsider the way in which plants are classified as ozone tolerant or sensitive.     

A test of the effect of supplemental UV-B radiation on the common frog, Rana temporaria L., during embryonic development

The release of certain man-made chemicals has led to recurrent, seasonal destruction of ozone in the upper atmosphere, allowing more solar radiation in the UV-B waveband to reach the Earth. Consequently, many amphibians may suffer increased exposure to UV-B at various stages in their lives. Embryonic stages of species which spawn in the spring, in shallow, open water, are at high risk of increased exposure. We exposed newly fertilized eggs of one such species, Rana temporaria L., to sunlight with and without supplemental UV-B. We used outdoor arrays of lamps to simulate the increase in UV-B which might result from previously documented ozone depletion. From immediately after fertilization to when hatchlings began feeding, ambient solar UV-B, weighted for DNA-damaging potential, was supplemented by ≈ 81% in 1995 and 113% in 1996. These levels of supplementation approximated the increase in solar UV-B expected to result from losses of 21% and 25%, respectively, of the total amount of ozone in the atmospheric column, relative to pre-ozone-depletion values. We found no evidence that these additions of UV-B radiation increased the incidence of mortality or overt developmental abnormality among embryos. We stress the need for appropriate dosimetry in studies of effects of UV-B on organisms.     

The impact of skin colour on human photobiological responses

Terrestrial solar ultraviolet radiation (UVR) exerts both beneficial and adverse effects on human skin. Epidemiological studies show a lower incidence of skin cancer in people with pigmented skins compared to fair skins. This is attributed to photoprotection by epidermal melanin, as is the poorer vitamin D status of those with darker skins. We summarize a wide range of photobiological responses across different skin colours including DNA damage and immunosuppression. Some studies show the generally modest photoprotective properties of melanin, but others show little or no effect. DNA photodamage initiates non‐melanoma skin cancer and is reduced by a factor of about 3 in pigmented skin compared with white skin. This suggests that if such a modest reduction in DNA damage can result in the significantly lower skin cancer incidence in black skin, the use of sunscreen protection might be extremely beneficial for susceptible population. Many contradictory results may be explained by protocol differences, including differences in UVR spectra and exposure protocols. We recommend that skin type comparisons be done with solar‐simulated radiation and standard erythema doses or physical doses (J/m²) rather than those based solely on clinical endpoints such as minimal erythema dose (MED).     

急性臭氧暴露对大鼠肺部细胞遗传毒性的影响*

目的: 探讨不同浓度臭氧急性暴露对大鼠肺部细胞的遗传毒性的影响。方法: 36只wistar大鼠随机分为对照组(过滤空气暴露)、臭氧暴露组(0.12 ppm、0.5 ppm、1.0 ppm、2.0 ppm、4.0 ppm)共6组,每组6只。以不同浓度的臭氧对大鼠进行动态染毒4 h后,取肺组织并分离单细胞,采用酶联免疫吸附法检测8-羟基脱氧鸟苷(8-OHdG),利用彗星实验、微核试验和DNA-蛋白质交联实验进行DNA和染色体损伤分析。结果: 与对照组相比,肺组织中8-OHdG含量从臭氧暴露浓度为0.12 ppm起即显著增加,在0.5 ppm时达到最高值。随着臭氧暴露浓度升高,彗星拖尾率逐渐上升,且存在明显的剂量-效应关系;DNA-蛋白质交联率有先升高后下降的趋势,且在2.0 ppm时达到最大值;而肺部细胞微核率尽管呈现出上升趋势,但与对照组相比无显著性差异。结论: 急性臭氧暴露在较低浓度(0.12 ppm)时即可导致大鼠肺部细胞的DNA损伤;而在较高浓度(4 ppm)时却未见显著的染色体损伤。     

Isoprene decreases the concentration of nitric oxide in leaves exposed to elevated ozone

Isoprene reduces visible damage (necrosis) of leaves caused by exposure to ozone but the mechanism is not known. Here we show that in Phragmites leaves isoprene emission was stimulated after a 3-h exposure to high ozone levels. The photosynthetic apparatus of leaves in which isoprene emission was inhibited by fosmidomycin became more susceptible to damage by ozone than in isoprene-emitting leaves. Three days after ozone fumigation, the necrotic leaf area was significantly higher in isoprene-inhibited leaves than in isoprene-emitting leaves. Isoprene-inhibited leaves also accumulated high amounts of nitric oxide (NO), as detected by epifluorescence light microscopy. Our results confirm that oxidative stresses activate biosynthesis and emission of chloroplastic isoprenoid, bringing further evidence in support of an antioxidant role for these compounds. It is suggested that, in nature, the simultaneous quenching of NO and reactive oxygen species by isoprene may be a very effective mechanism to control dangerous compounds formed under abiotic stress conditions, while simultaneously attenuating the induction of the hypersensitive response leading to cellular damage and death.     

Incidence,prevalence, mortality,disability-adjusted life years and risk factors of cancer in Australia and comparison with OECD countries, 1990–2015: findings from the Global Burden of Disease Study 2015

BackgroundComparative evidence on the burden, trend, and risk factors of cancer is limited. Using data from the Global Burden of Disease (GBD) study, we aimed to assess cancer burden – incidence, prevalence, mortality, disability-adjusted life years (DALYs) – and attributable risk factors for Australia between 1990 and 2015, and to compare them with those of 34 members of the Organisation for Economic Co-operation and Development (OECD).MethodsThe general GBD cancer estimation methods were used with data input from vital registration systems and cancer registries. A comparative risk assessment approach was used to estimate the population-attributable fractions due to risk factors.ResultsIn 2015 there were 198,880 (95% uncertainty interval [UI]: 183,908–217,365) estimated incident cancer cases and 47,562 (95% UI: 46,061–49,004) cancer deaths in Australia. Twenty-nine percent (95% UI: 28.2–29.8) of total deaths and 17.0% (95% UI: 15.0–19.1) of DALYs were caused by cancer in Australia in 2015. Cancers of the trachea, bronchus and lung, colon and rectum, and prostate were the most common causes of cancer deaths. Thirty-six percent (95% UI: 33.1–37.9) of all cancer deaths were attributable to behavioral risks. The age-standardized cancer incidence rate (ASIR) increased between 1990 and 2015, while the age-standardized cancer death rate (ASDR) decreased over the same period. In 2015, compared to 34 other OECD countries Australia ranked first (highest) and 24^th based on ASIR and ASDR, respectively.ConclusionThe incidence of cancer has increased over 25 years, and behavioral risks are responsible for a large proportion of cancer deaths. Scaling up of prevention (using strategies targeting cancer risk factors), early detection, and treatment of cancer is required to effectively address this growing health challenge.