Long-term exposure to urban air pollution and lung cancer mortality: A 12-year cohort study in Northern China.

Cohort evidence that links long-term exposures to air pollution and mortality comes largely from the United States and European countries. We investigated the relationship between long-term exposures to particulate matter <10µm in diameter (PM10), nitrogen dioxide (NO2), and sulfur dioxide (SO2) and mortality of lung cancer in Northern China. A cohort of 39,054 participants were followed during 1998-2009. Annual average concentrations for PM10, NO2, and SO2 were determined based on data collected from central monitoring stations. Lung cancer deaths (n=140) were obtained from death certificates, and hazard ratios (HRs) were estimated using Cox proportional hazards models, adjusting for age, gender, BMI, education, marital status, smoking status, passive smoking, occupation, alcohol consumption, etc. Each 10mg/m(3) increase in PM10 concentrations was associated with a 3.4%-6.0% increase in lung cancer mortality in the time-varying exposure model and a 4.0%-13.6% increase in the baseline exposure model. In multi-pollutant models, the magnitude of associations was attenuated, most strongly for PM10. The association was different in men and women, also varying across age categories and different smoking status. Substantial differences exist in the risk estimates for participants based on assignment method for air pollution exposure.

[Identifying sources of nitrate in surface water of Jiulong River Watershed].

Two representative catchments, Wuchuang catchment and Xiandu catchment, were selected from Jiulong River Watershed as study areas to trace sources of nitrate in surface water by using 15N isotope technique. In the spring of 2005, the surface water samples were twice collected from the catchments and determined for dissolved total nitrogen (DTN), nitrate nitrogen (NO3(-)-N), ammonia nitrogen (NH4+-N) and delta 15N value of nitrate. The results showed that in the samples from Xiandu catchment, the concentration ranges of DTN, NO3(-)-N and NH4+-N were 1.47-5.31 mg/L, 0.83-4.05 mg/L and 0.21-0.36 mg/L respectively, and the delta 15N values of nitrate ranged from 2.54 per thousand to 7.92 per thousand; in the samples from Wuchuang catchment, the concentration ranges of DTN, NO3(-)-N and NH4+-N were 1.14-5.56 mg/L, 0.96-1.46 mg/L and 0.12-1.28 mg/L respectively, and the delta 15N values of nitrate were between -0.19 per thousand and 5.89 per thousand. In contrast with the typical ranges of delta 15N isotopic signature of nitrate from different sources and in consideration of the information of local crop planting circumstances and application of fertilizers, the data indicated that the first, the nitrate in the surface water of Xindu catchment mainly came from inorganic fertilizers and soil organic nitrogen, and some originated from organic fertilizers; the second, the nitrate in the surface water of Wuchuang catchment mostly flowed from inorganic fertilizers and soil organic nitrogen, and few derived from organic fertilizers; the third, the sources of nitrate varied with the sampling location and time and were dependent on the kinds of local crops and their planting seasons.

[Wet deposition of atmospheric nitrogen in Jiulong River Watershed].

Spatio-temporal distributions and sources of atmospheric nitrogen (N) in precipitation were examined for Jiulong River Watershed (JRW), an agricultural-dominated watershed located in southeastern China with a drainage area of 1.47 x 10(4) km2. During 2004-2005, 847 rain samples were collected in seventeen sites and analyzed for ammonium N, nitrate N and dissolved total N (DTN) followed by filtration through 0.45 microm nucleopore membranes. Atmospheric N deposition flux was calculated using GIS interpolation technique (Universal Kriging method for precipitation, Inverse distance weighted technique for N) based on measured N value and precipitation data from eight weather stations located in the JRW. ArcView GIS 3.2 was used for surface analysis, interpolation and statistical work. It was found that mean DTN concentration in all sites ranged between 2.20 +/- 1.69 and 3.26 +/- 1.37 mg x L(-1). Ammonium, nitrate and dissolved organic N formed 39%, 25% and 36% of DTN, respectively. N concentration decreased with precipitation intensity as a result of dilution, and showed a significant difference between dry season and wet season. The low isotope value of nitrate delta 15N ranging between -7.48 per thousand and -0.27 per thousand (mean: -3.61 per thousand) indicated that the increasing agricultural and soil emissions together with fossil combustions contributed to atmospheric nitrate sources. The annual wet deposition of atmospheric N flux amounted to 9.9 kg x hm(-2), which accounts for 66% of total atmospheric N deposition flux (14.9 kg x hm(-2)). About 91% of wet atmospheric deposition occurred in spring and summer. The spatio-temporal variation of atmospheric N deposition indicated that intensive precipitation, higher ammonia volatilization from fertilizer application in the growing season, and livestock productions together provided the larger N source.

[The analysis and comparison of different edge detection algorithms in ultrasound B-scan images].

In this paper, some familiar algorithms of edge detection in ultrasound B-scan images are analyzed and studied. The results show that Sobel, Prewitt and Laplacian operators are sensitive to noise, Hough transform adapts to the whole detection, while LoG algorithm's average is zero and it couldn't change the whole dynamic area. Accordingly LoG algorithm is preferable.

[Modelling pollutant loads and management alternatives in Jiulong River watershed with AnnAGNPS].

The modelling package Annualized Agricultural Nonpoint Source Model (AnnAGNPS) was used to predict pollutant loads, and simulate catchment processes and management practices in Jiulong River watershed, a medium-sized mountainous watershed in southeast of China. Four typical sub-watersheds were primarily chosen to calibrate AnnAGNPS model by data collected from storm events during the period of April to September, 2003. The model was further validated in the two biggest branches of Jiulong River watershed, i.e. West river and North river by the data regarding climate, and land using condition in 2002 - 2003. The simulation results show that annual total nitrogen load was 24.76kg/(hm2 x a) and 10.28kg/(hm2 x a) in the West river and North river, respectively, and annual total phosphorus load was 0.67 kg/(hm2 x a) and 0.40 kg/(hm2 x a) in the West river and North river, respectively. With the support of AnnAGNPS model, several management alternatives were separately simulated in the typical sub-watersheds, West river and North river. In the specific cell with cell-ID of 92 in Tianbao and Xiandu sub-watershed, after reforesting in sloping field, runoff surface, sediment yield, total nitrogen load and total phosphorus load cut down with 21.6%, 25.9%, 96% and 79.2%, respectively. In West river, with the cultivation plant changing from banana into rice, the total nitrogen, dissolved nitrogen, total phosphorus and dissolved phosphorus cut down with 23.83%, 25.44%, 9.08% and 19.84%, respectively. In North river, when removing all the hoggerys, nitrogen and dissolved nitrogen cut down with 63.54% and 76.92% , respectively.

Heavy metals in surface sediments from Minjiang Estuary-Mazu and Xiamen-Jinmen Sea areas.

The concentrations of Cu, Pb, Zn and Cd in surface sediments from Minjiang Estuary-Mazu and Xiamen-Jinmen sea areas of China were investigated during 1995-1996. The concentration ranges of Cu, Pb, Zn and Cd in the Minjiang Estuary-Mazu sea area were 16.4-37.2, 33.4-69.6, 92.1-128, 0.087-0.336 mg/kg(dry wt.), respectively; those for Xiamen-Jinmen sea area were 11.0-24.5, 36. 0-80.3, 77.5-161, 0.135-0.285 mg/kg(dry wt.), respectively. The concentrations and distributions of Cu, Pb, Zn and Cd in surface sediments of Minjiang Estuary-Mazu and Xiamen-Jinmen sea areas were analyzed and evaluated. The results showed that the values of Zn and Pb exceeded those of sediment quality criteria. The average concentration of Cu in Minjiang Estuary-Mazu sea area was higher than that in Xiamen-Jinmen sea area. The obviously higher concentrations of Cu, Pb, Zn and Cd were found at outlets of Minjiang and Jiulong River. From the estuaries to open sea, the concentrations of Cu, Pb, Zn and Cd had a decreasing trend, and then elevated in the sea areas near Mazu and Jinmen, suggesting that Cu, Pb, Zn and Cd in Minjiang Estuary-Mazu and Xiamen-Jinmen sea areas may come from both the mainland and Taiwan of China.