首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   166篇
  免费   16篇
  国内免费   63篇
安全科学   15篇
环保管理   10篇
综合类   107篇
基础理论   78篇
污染及防治   14篇
评价与监测   15篇
社会与环境   5篇
灾害及防治   1篇
  2023年   4篇
  2022年   3篇
  2021年   2篇
  2020年   7篇
  2019年   8篇
  2018年   6篇
  2017年   8篇
  2016年   12篇
  2015年   5篇
  2014年   5篇
  2013年   35篇
  2012年   12篇
  2011年   11篇
  2010年   8篇
  2009年   9篇
  2008年   14篇
  2007年   7篇
  2006年   13篇
  2005年   7篇
  2004年   7篇
  2003年   5篇
  2002年   4篇
  2001年   11篇
  2000年   4篇
  1999年   2篇
  1998年   2篇
  1997年   2篇
  1996年   6篇
  1995年   8篇
  1994年   4篇
  1993年   2篇
  1992年   2篇
  1991年   3篇
  1990年   2篇
  1989年   2篇
  1988年   1篇
  1983年   1篇
  1977年   1篇
排序方式: 共有245条查询结果,搜索用时 937 毫秒
1.
A case of type III congenital cystic adenomatoid malformation of the lung was successfully diagnosed prenatally by fetal lung biopsy. We performed this procedure at 22 weeks of gestation, using a biopsy gun system under ultrasound guidance. The pregnancy was undisturbed by the procedure but as the condition was incompatible with life, an abortion was performed. The diagnosis was confirmed at post-mortem examination. Fetal lung biopsy appears to be a useful method for prenatal diagnosis of fetal lung disorders.  相似文献   
2.
南宁城市大气污染对人体健康的危害及治理对策   总被引:6,自引:0,他引:6  
南宁市大气属煤烟型污染 ,大气的主要污染物为SO2 、NOx、TSP、降尘 ,虽然随着环境管理和污染治理工作的加强 ,污染物浓度逐年下降 ,但是工业区大气污染仍然较重。污染物流行病学调查显示 :工业区癌症和呼吸系统疾病死亡率均高于全市平均水平 2倍左右 ,城区又高于郊区 2倍 ,大气污染综合指数与呼吸内科门诊就诊人数呈正相关。用邓聚龙的灰色系统理论分析得知污染物对癌症和呼吸系统疾病死亡率有关联 ,关联度从大到小排序为 :TSP >降尘 >SO2 >NOx ,最后提出了大气污染治理的对策。  相似文献   
3.
中国乳腺癌与土壤环境中化学元素的相关性研究   总被引:12,自引:1,他引:12  
利用土壤元素资料2069448个数据、乳腺癌死亡调查资料31320例,研究了乳腺癌死亡率与人群生存的土壤环境中64个元素的相关性。结果表明,砷、汞、钡、铊、钕、铀、锆、锑等元素与乳腺癌死亡率有相关性。等级相关系数分别为-0.6820(P〈0.0005)、0.4567(P〈0.01)、-0.3773(P〈0.025)、-0.3852(P〈0.025)、0.3179(P〈0.05)、-0.4377(P〈  相似文献   
4.
饮用水中亚硝酸盐及微量元素对癌症发病率的影响研究   总被引:3,自引:0,他引:3  
从环境地理学和环境化学的角度出发,研究了饮用水中亚硝酸盐以及微量元素的分布与癌症发病率的关系。在对江苏省如皋地区饮用水水样检测的基础上,指出研究区的饮用水中虽然亚硝酸盐严重超标,但是并没有与癌.症发病率形成相关性。同时运用方差分析方法时饮用水中的微量元素进行研究,选出了若干种与如皋地区的癌症发病率存在很强相关性的微量元素,并讨论了这些元素的分布特征与癌症发病率的具体关系。  相似文献   
5.
Routine ultrasound examination at 30 weeks gestation revealed an intrapulmonary cystic mass in an otherwise normal fetus. Following delivery at term, the diagnosis of congenital cystic adenomatoid malformation of the right lung was confirmed, and an elective right middle lobectomy successfully performed at nine days of age.  相似文献   
6.
气态甲醛对大鼠肺组织影响的病理学观察   总被引:1,自引:1,他引:0  
为了研究大鼠吸入甲醛后其肺组织病理结构的改变并探讨其损伤机理,以雌性Wisar大鼠为实验材料,采用动式吸入方式染毒15d(暴露组甲醛浓度32~37mg·m-3,每日暴露4h)后,取肺组织进行光镜及透射电镜观察.光镜观察结果表明,甲醛暴露后,大鼠肺组织主要表现为间质性肺炎和肺泡性肺炎的病理学特点,肺泡壁毛细血管扩张、充血、出血严重,个别区域可见大量炎细胞浸润,肺内细支气管和肺泡腔内见大量血细胞,部分肺泡腔内有透明膜形成,内含脱落的肺泡上皮细胞.电镜观察结果表明,甲醛暴露后,大鼠肺泡上皮细胞损伤严重,线粒体嵴断裂、肿胀、空泡化,部分肺泡上皮细胞胞膜溶解,细胞器丢失,细胞坏死、脱落.推测甲醛吸入可致大鼠肺病理损伤,损伤机理可能与自由基损害和醛糖还原酶(AR)表达变化有关.  相似文献   
7.
Nitrate contamination of water sources is a concern where large amounts of nitrogen fertilizers are regularly applied to soils. Ingested nitrate from dietary sources and drinking water can be converted to nitrite and ultimately to N-nitroso compounds, many of which are known carcinogens. Epidemiologic studies of drinking water nitrate and cancer report mixed findings; a criticism is the use of nitrate concentrations from retrospective drinking water data to assign exposure levels. Residential point-of-use nitrate data are scarce; gaps in historical data for municipal supply finished water hamper exposure classification efforts. We used generalized linear regression models to estimate and compare historical raw water and finished water nitrate levels (1960s--1990s) in single source Iowa municipal supplies to determine whether raw water monitoring data could supplement finished water data to improve exposure assessment. Comparison of raw water and finished water samples (same sampling date) showed a significant difference in nitrate levels in municipalities using rivers; municipalities using other surface water or alluvial groundwater had no difference in nitrate levels. A regional aggregation of alluvial groundwater municipalities was constructed based on results from a previous study showing regional differences in nitrate contamination of private wells; results from this analysis were mixed, dependent upon region and decade. These analyses demonstrate using historical raw water nitrate monitoring data to supplement finished water data for exposure assessment is appropriate for individual Iowa municipal supplies using alluvial groundwater, lakes or reservoirs. Using alluvial raw water data on a regional basis is dependent on region and decade.  相似文献   
8.
Food crops such as cassava, cocoyam and other tuber crops grown in mining communities uptake toxic or hazardous chemicals such as arsenic, and cadmium, from the soil. Cassava is a stable food for Ghanaians. This study evaluated human health risk from eating cassava grown in some mining communities in Ghana such as Bogoso, Prestea, Tarkwa and Tamso, which are important mining towns in the Western Region of Ghana. The study evaluated cancer and non-cancer health effects from eating cassava grown in the study areas in accordance with US Environmental Protection Agency’s Risk Assessment guidelines. The results of the study revealed the following: cancer health risk for Tamso, 0.098 (RME – Reasonable Maximum Exposure) and 0.082 (CTE – Central Tendency Exposure). This means that approximately 10 and 8 out of 100 resident adults are likely to suffer from cancer related cases by RME and CTE parameters respectively. For Prestea, we have 0.010 and 0.12, which also means that approximately 1 out of 100 and 10 resident adults out of 100 are also likely to suffer from cancer related diseases by RME and CTE parameters. The results of the study obtained were found to be above the acceptable cancer risk range of 1× 10−6 to 1× 10−4, i.e., 1 case of cancer out of 1 million or 100,000 people respectively.  相似文献   
9.
In Vietnam, Nicotex's site is perhaps the most infamous case of illegal disposal of toxic pesticides near residential areas. In 2013, affected villagers discovered illegal burials of around 1,000 tons of expired pesticides in the Nicotex factory. Organic pesticides were detected in illegal burial areas (IBAs) around 60 times greater than acceptable levels, but no attention was paid to contamination of metals, metalloids, and other classes of organic contaminants, which could be co-contaminants in pesticide formulation. This study assessed the contaminants remaining in the IBAs and surrounding residential areas two years after the source removal conducted in 2014. Additionally, a preliminary health risk assessment from residual contaminants was performed. Nine classes of chemicals including parental pesticides, inorganic and organic degradation byproducts, and metals and metalloids, comprising 123 chemicals were quantified in soil, sediment, and water samples from Nicotex and surrounding residential areas. Although concentrations of organic pesticides were below acceptable levels, arsenic contamination in the soil in a Nicotex IBA named NCT5 and Nap village (NV) exceeded the acceptable level. The enrichment factor and log-probability plot indicate that arsenic enrichment at NV is not from natural sources but is associated with arsenic contamination in NCT5. Arsenic may be a co-contaminant in pesticide manufacturing or an arsenical pesticide, such as monosodium methanearsonate. Arsenic found in NV was toxic arsenate for which the preliminary risk assessment yielded an unacceptable excess carcinogenic risk (1 × 10?4). While all attention was paid to investigate and treat contamination of organic pesticides, it turns out that arsenic is the major existing threat which poses an unacceptable cancer risk in good agreement with the high cancer rate claimed by villagers near Nicotex. This justifies the need for further investigation of the extent of the arsenic contamination and restoration of the contaminated land.  相似文献   
10.
为评估由我国大气中α HCH所导致的人体健康风险,利用CanMETOP 模拟的2005年日均α HCH大气浓度,基于吸入因子和致癌风险进行研究。结果表明年吸入因子呈东部>西部,北部>南部的特征,东中和东北部地区的吸入因子分别主要由人口密度和α HCH大气浓度贡献,东中和东南部地区的个体健康损失小于东北地区,东中和东南部地区年内逐月吸入因子分配较为均匀,而东北地区主要集中的夏季,东北地区个体致癌风险系数明显高于中部和南部。推测由其它污染物所形成的暴露风险具有类似的时空分布。加之夏季东北地区集中降水所形成的湿沉降以及气温升高等因素,使摄食暴露和皮肤接触暴露增大,东北地区人群的复合暴露风险将显著大于其它地区  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号