Input Quantity and Distribution of Hexachlorocyclohexane (HCH) in the Jiaozhou Bay Waters

Based on data from the investigation in Jiaozhou bay waters in May, July and November in 1987, the distribution, source and seasonal variation of HCH in Jiaozhou Bay are analyzed. The results showed that in Jiaozhou bay HCH content was very low and less than 0.100 μg/L in this year, and better than the national Category I of the sea water quality standard, and the water quality about HCH was very clean;and that The seasonal variation of the HCH content in Jiaozhou bay waters has already vanished, namely, the seasonal variation of the HCH content in this year was not influenced by the rainfall, the runoffs or rivers. The horizontal distributions of the HCH content in the whole bay waters showed that the HCH content in the bay was not only directly input from both runoffs but also from rivers, the HCH source was area-source and came from land. The vertical distributions of the HCH content in the whole bay waters showed that the change of the HCH content at surface was not consistent with the corresponding one at bottom, and that the trend of the HCH distribution at surface was not consistent with that at bottom, and that only the HCH contents at surface and bottom were very close. From the year of four years ago of the prohibition (1979), to the prohibition year of HCH use (1983), and finally to the year after the four years of the prohibition (1987), The change of the HCH input into the bay waters unveiled that the by four years before the prohibition, the pollution of the HCH on land was very grave, and by four years after the prohibition, the HCH content in waters was very low, whose process represented that the process of human being having broken up the earth and the process of the earth having naturally restored. Therefore, Human being would consider not only for own benefits but also for the sustainable development of environment.

Human Discharge and Phytoplankton Takeup for The Atmospheric Carbon Balance

By the data of the Jiaozhou Bay (Shandong, China) from May 1991 to February 1994 and those of Hawaii from March 1958 to December 2007, with the statistics and differential equations analyzed were the seasonal variations in atmospheric carbon in the Northern Pacific Ocean (NPO), and in phytoplankton primary production in the Jiaozhou Bay, and its relationship in the study regions. The study unveiled that the seasonal change of the atmosphere carbon and primary production has the same period. In a year, the primary production and atmosphere carbon had two balance points: the points of May and October, during which the amount of atmosphere carbon decreased. As phytoplankton absorbed atmosphere carbon, When primary production in spring > 181.60 (mg/m2 d) ~ 297.57 (mg/m2 d) or 754.74 (mg/m2 d) ~ 1160.13 (mg/m2 d) in Sept. or 552.94 (mg/m2 d) ~ 890.69 (mg/m2 d) in Oct, the atmosphere carbon fell. Therefore, it is considered that from May to Oct. every year, phytoplankton growing in bloom controlled the increase of atmosphere carbon. From Dec. to next April, human discharging the carbon controlled its increase. The results supported the viewpoint shown by Yang (2010): the variation in atmospheric carbon was determined by human discharge and phytoplankton growth. The result in this paper showed that the earth ecosystem kept the percentage of the decrease amount of atmospheric carbon to its amount taken up by phytoplankton as 1.60% ~ 0.34% and maintained the dynamic balance of carbon by emitted by human being into the atmosphere and absorption of phytoplankton to atmosphere carbon. Therefore, the ecosystem was considered to be of the great power and accuracy.

Distribution of Diuron in Coastal Seawater and Sediments from West Sea Area of Zhoushan Island

The pollution level of diuron in seawater and sediments in the west coastal sea area of Zhoushan Island from 2011 to 2013 was investigated. Results revealed that the concentration of diuron in seawater varies from less than (3.0 to 52.1) ng·L-1, with an average level of less than 11.1 ng.L-1. The annual average content was less than 7.9 ng.L-1, 13.9 ng.L-1, and 12.3 ng.L-1 in 2011, 2012, and 2013, respectively. The concentrations of diuron in marine sediments also varied from less than (0.3 to 3.9) ng.g-1 (dry weight), with an average concentration of less than 1.13 ng g-1 (dry weight). The annual average concentration was less than 0.851 ng.g-1, 1.328 ng.g-1, and 1.202 ng.g-1 in 2011, 2012, and 2013, respectively. The accumulation of diuron in seawater and sediments may pose a potential risk to the marine ecosystem of the investigated sea area.

An innovative three-layer strategy in response to a quartan malaria outbreak among forest goers in Hainan Island,China:a retrospective study

Background:An outbreak of Plasmodium malariae infection among forest goers in Sanya City of Hainan Island,China was reported in 2015.In response to this outbreak,an innovative three-layer strategy(TLS)targeted forest goers was adapted based on the 1-3-7 approach.Main text:Key elements of TLS are:(i)The village with fve malaria cases and adjacent villages were set as the frst layer.All residents including forest goers were taken as the high-risk population(HRP).Active case detection(ACD)by blood smear microscopy and PCR was selected as the primary measure,and passive case detection(PCD)as complementary measure.One case was identifed under TLS implementation.(ii)The township with cases(Gaofeng Town)and the nearby towns were chosen as the second layer.Only forest goers were screened by ACD,while PCD as a routine screening method.7831 blood smears collected by ACD and PCD and tested with negative results.(iii)The city with cases(Sanya City)and others 12 counties/county-level cities were selected as the third layer.Malaria cases were monitored passively.A total of 77,555 blood slides were screened by PCD with zero positive sample.For each layer,the malaria vector mosquitoes were monitored using light traps,cattle-baited/human-bait traps.Anopheles minimus(dominant species),An.sinensis and An.dirus were captured.Vector control measures mainly include insecticide residual spraying and long-lasting insecticide nets.The capacity of clinicians,public health practitioners and laboratory technicians has been improved through training.During 2016‒2018,TLS and chemoprophylaxis were implemented in the same areas.In the frst layer,all residents were monitored by ACD,and malaria chemoprophylaxis were distributed,89.5%of forest goers were using chemoprophylaxis against malaria.The blood smears(3126 by ACD plus 1516 by PCD)were with zero positive results.Chemoprophylaxis and ACD were ofered to forest goers once a year,and PCD in residents as a complementary measure in the second and third layer,77.8%and 95.1%of forest goers received chemoprophylaxis.In each layer,vector surveillance and control of malaria and trainings for medical staf Conclusions:TLS was efective in blocking the outbreak by P.malariae among forest goers in Hainan in malaria elimination stage.However,whether it could prevent the malaria resurgence in the post-elimination phase needs to be further assessed.