Letters to The Editor

Abstract

Since 1990, basic knowledge of the “chemical climate” of fine particles, has greatly improved from Junge’s compilation from the 1960s. A worldwide baseline distribution of fine particle concentrations on a synoptic scale of approximately 1000 km can be estimated at least qualitatively from measurements. A geographical distribution of fine particle characteristics is deduced from a synthesis of a variety of disparate data collected at ground level on all continents, especially in the northern hemisphere. On the average, the regional mass concentrations range from 1 to 80 μg/m³, with the highest concentrations in regions of high population density and industrialization. Fine particles by mass on a continental and hemispheric spatial scale are generally dominated by non-sea salt sulfate (0.2 to ～20 μg/m³, or ～25%) and organic carbon (0.2->10 μg/m³, or ～25%), with lesser contributions of ammonium, nitrate, elemental carbon, and elements found in sea salt or soil dust. The crustal and trace metal elements contribute a varied amount to fine particle mass depending on location, with a larger contribution in marine conditions or during certain events such as dust storms or volcanic disturbances. The average distribution of mass concentration and major components depends on the proximity to areal aggregations of sources, most of which are continental in origin, with contributions from sea salt emissions in the marine environment. The highest concentrations generally are within or near very large population and industrial centers, especially in Asia, including parts of China and India, as well as North America and Europe. Natural sources of blowing dust, sea salt, and wildfires contribute to large, intermittent spatial-scale particle loadings beyond these ranges. A sampling of 10 megacities illustrates a range of characteristic particle composition, dependent on local and regional sources. Long-range transport of pollution from spatially aggregated sources over hundreds of kilometers creates persistent regional- and continental-scale gradients of mass concentration, sulfate, and carbon species especially in the northern hemisphere. Data are sparse in the southern hemisphere, especially beyond 45° S, but are generally very low in mass concentrations.     

浅谈环境信访增多的成因及对策

剖析了海门市环境信访增多的主要表现及形成原因，阐述了领导重视是做好环境信访的基础，针对企业违法行为屡禁不止是环境信访多、查处难的主要矛盾，从环境信访和环境日常监察的关系方面，对坚持“两手抓治本控源”方法进行了初探，强调了必须全面落实环境信访责任制和提高信访调处队伍素质，就切实做好环境信访提出了建议与对策。     

Estimation of dioxin risk to Japanese from the past to the future

The transport processes of seventeen 2,3,7,8-chlorinated congeners of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from their major sources to humans were modeled to estimate the time course, from the past to the future, of the human health risk to the Japanese population. The comparison between measured and estimated values showed that the present modeling approach represented the background levels of congeners in the environment, daily intake, and body burden reasonably well, except for in the case of 2,3,7,8-TCDF. Although PCDD/Fs in herbicides have contributed greatly to the daily intake and body burden to the Japanese population in the past, the main sources of the present intake and burden of PCDD/Fs is estimated to be incinerators. The margin of exposure (MOE) for the risk of morphological reproductive alteration in female offspring exposed prenatally was calculated based on the estimated maternal body burden. The results indicated that the MOE values were in the single digits, implying that these values may not be sufficiently large to guarantee the safety of female offspring of mothers born in the 1950s, whereas the MOE values for female offspring born in and after the latter half of the 1990s may be sufficiently large to guarantee safety.     

Reconnecting to the Biosphere

Humanity has emerged as a major force in the operation of the biosphere, with a significant imprint on the Earth System, challenging social-ecological resilience. This new situation calls for a fundamental shift in perspectives, world views, and institutions. Human development and progress must be reconnected to the capacity of the biosphere and essential ecosystem services to be sustained. Governance challenges include a highly interconnected and faster world, cascading social-ecological interactions and planetary boundaries that create vulnerabilities but also opportunities for social-ecological change and transformation. Tipping points and thresholds highlight the importance of understanding and managing resilience. New modes of flexible governance are emerging. A central challenge is to reconnect these efforts to the changing preconditions for societal development as active stewards of the Earth System. We suggest that the Millennium Development Goals need to be reframed in such a planetary stewardship context combined with a call for a new social contract on global sustainability. The ongoing mind shift in human relations with Earth and its boundaries provides exciting opportunities for societal development in collaboration with the biosphere--a global sustainability agenda for humanity.