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1.
Shouta M. M. Nakayama Yoshinori Ikenaka Kyohei Hamada Kaampwe Muzandu Kennedy Choongo John Yabe Takashi Umemura Mayumi Ishizuka 《Environmental monitoring and assessment》2013,185(6):4907-4918
The lead–zinc (Pb–Zn) mine in Kabwe City and the copper–cobalt (Cu–Co) mine in the Copperbelt Province are major mining areas in Zambia. To examine the effects of metal pollution on wildlife, wild black rats (Rattus rattus and Rattus tanezumi) were captured in Kabwe and Chingola (in the Copperbelt Province), and in Lusaka (a noncontaminated site). Wild black rats in Kabwe accumulated significantly higher concentrations of Pb and Cd in various organs than rats from Lusaka. In Chingola, significantly higher concentrations of Cu, Co, Pb, and Cd were accumulated in wild black rats than in rats from Lusaka. These results were in accordance with metal accumulation patterns in soil. From toxicological aspects, concentrations of Pb and Cd in rats were generally low. However, metallothionein-1 (MT-1) and metallothionein-2 (MT-2) mRNA expression levels in wild black rats from Kabwe were significantly higher than those in rats from Lusaka. A generalized linear model (GLM) showed that concentrations of Zn and Cu had positive effects on the MT-1 and MT-2 mRNA expression. These results suggest that wild black rats in Zambian mining sites were exposed to metals that accumulated in their organs, causing biological responses such as MT mRNA induction. GLM indicated that heme oxygenase-1 (HO-1) mRNA expression could be a marker for Cr exposure. 相似文献
2.
By using fluidized-bed furnace and rotary-kiln+stoker furnace and four different kinds of industrial wastes such as waste wood, coffee mill, waste oils and waste plastics, we have drawn the following conclusions:
(1) A relationship between H6CBz and DXN is acquired, which is DXN=0.34×H6CBz1.1.
(2) The following means of emission reduction can be considered. (a) Reduction of DXN and Cl accumulation within the furnace, (b) control by the incinerated object, (c) control through the precursors of H6CBz, (d) improvement through operational control, (e) ammonia injection into the high-temperature zone of the furnace seems to be effective in reducing DXN and (f) DXN concentration is high with CO above 1800 ppm, though it decreases with CO below ≈10 ppm. 相似文献
3.
The lipid antioxidative activities of polyphenols with high oxygen radical capacities need to be measured at low oxygen tensions. In this study, differences in the reactivity of catechins and resveratrols towards alkyl (R*) and peroxy (PhCOO*) radicals were observed at lower oxygen pressures. The radical scavenging activities for catechin, epicatechin, resveratrol and n-propyl gallate with or without 2-mercapto-1-methylimidazole (MMI), a thiol were investigated by differential scanning calorimetry (DSC) monitoring of the polymerization of methyl methacrylates (MMA) initiated by 2,2'-azobisisobutyronitrile (AIBN, an R* radical) or benzoyl peroxide (BPO, an PhCOO* radical) at 70 degrees C under nearly anaerobic conditions. Catechin, epicatechin and resveratrol with MMI, but not n-propyl gallate showed the less length of induction period than that for corresponding ones without MMI, probably resulting from the reaction of MMI radicals with molecular oxygen in the system. Also, the inhibitory rate of propagation (R(inh)) for catechin and resveratrol in the BPO system was much more greater than that in the AIBN system. The reactivity of catechins and resveratrol with R() or PhCOO* radical was considerably different, whereas n-propyl gallate did not different between radicals under nearly anaerobic conditions. 相似文献
4.
Establishing marine protected areas (MPAs) helps to restore and sustain marine and fishery resources, but in the Philippines only 20% of total MPAs are achieving their management objectives. We conducted a case study of a small MPA in Northern Philippines to understand socio-economic status and livelihoods of the fishermen stakeholders, and examine their attitudes and perceptions on marine resource values and conservation. Using an ordered probit model, we also investigated factors affecting these perceptions. We found a lower fish income ratio in higher income quartiles, a small share of local non-fishery income, and an apparent lack of other livelihood opportunities within the rural economy. The majority of fishermen had positive perceptions of the non-market value of marine resources, agreed with the need for MPAs, and perceived positive potential income benefit from MPAs. Level of education and fishing income were consistent significant positive determinants of these perceptions. Policy implications suggest: involving likely-to-be-displaced reef fishers in the crafting of management plans; conducting intensive research on appropriate and feasible livelihood options, for example, marine culture technologies; and designing explicit strategies to increase the propensity of coastal households to invest in children's education as a strategy for long-term sustainability of resource management. 相似文献
5.
A simple system to evaluate the 222Rn (radon) exhalation rate from soil has been improved. A sampling cuvette of 2.1 L is placed so that it covers the targeted ground soil, and radon emanating from the soil accumulates within the cuvette for 24 h. Its internal radon concentration is measured by the combination of an activated charcoal (PICO-RAD) and a liquid scintillation counting system. This study shows variations of the conversion factor (CF: unit Bq m(-3)/cpm) of PICO-RAD. The range of CF due to temperature (10-30 degrees C) was between -21% and +69%, and this due to humidity (30-90%) was between 0% and -15%. Humidity and radon concentration in the cuvette covering soil tended to saturate in a few hours. The above information was used to correct the CF for the evaluation. The improved system shows high reliability and can be easily applied to natural environments. 相似文献
6.
Yohannes Yared Beyene Nakayama Shouta M. M. Yabe John Toyomaki Haruya Kataba Andrew Nakata Hokuto Muzandu Kaampwe Ikenaka Yoshinori Choongo Kennedy Ishizuka Mayumi 《Environmental science and pollution research international》2022,29(5):6622-6632
Environmental Science and Pollution Research - Interindividual genetic variations determine human’s susceptibility to heavy metal-induced toxicity. Thus, we analyzed blood concentrations of... 相似文献
7.
Ikenaka Y Eun H Watanabe E Kumon F Miyabara Y 《Environmental pollution (Barking, Essex : 1987)》2005,138(3):529-537
To elucidate the historical changes in polychlorinated dibenzo-p-dioxin (PCDD), polychlorinated dibenzofuran (PCDF), coplanar polychlorinated biphenyl (co-PCB), and polycyclic aromatic hydrocarbon (PAH) inflows in Lake Suwa, their concentrations in the sediment core were analyzed in 5 cm interval. The maximum concentrations (depth cm) of PCDDs/DFs, co-PCBs, and PAHs were 25.2 ng/g dry (30-35 cm), 19.0 ng/g dry (30-35 cm), and 738, 795 ng/g dry (50-55 cm, 30-35 cm), respectively. Age and sedimentation rate of the sediment were estimated from the vertical changes in apparent density. Deposition rate of dioxins and PAHs were calculated from the concentration and sedimentation rate of the sediment. The results indicate that large amounts of dioxins and PAHs flowed into the lake in flood stage compared to normal stage. 相似文献
8.
Whether communities respond smoothly or discontinuously to changing environmental conditions has important consequences for the preservation and restoration of ecosystems. Theory shows that communities may exhibit a variety of responses to environmental change, including abrupt transitions due to the existence of alternate states. However, there have been few opportunities to look for such transitions in nature. Here, we examine the impact of a two-orders-of-magnitude decrease and then increase in planktivore abundance in Wintergreen lake (Michigan, USA), caused by the extinction and reintroduction of two dominant fish species (largemouth bass, Micropterus salmoides, and bluegill, Lepomis macrochirus). Over a 16 + yr period of slow change from high planktivory to low planktivory back to high planktivory, the zooplankton community changed smoothly and predictably between states. In years of low planktivory, the zooplankton assemblage was dominated by a single, large, cladoceran species, Daphnia pulicaria, whereas in years of high planktivory, D. pulicaria disappeared and was replaced by a suite of small-bodied cladocerans. We quantified the multivariate change in zooplankton community dissimilarity and found that community state smoothly tracked changes in planktivore density in both a forward and backward direction. Thus, there was little evidence of discontinuity in this system where transitions are strongly driven by planktivory. 相似文献
9.
Nakayama SM Ikenaka Y Hamada K Muzandu K Choongo K Teraoka H Mizuno N Ishizuka M 《Environmental pollution (Barking, Essex : 1987)》2011,159(1):175-181
Metal (Cr, Co, Cu, Zn, Cd, Pb, Ni) and metalloid (As) accumulation was studied in roadside soil and wild rat (Rattus sp.) samples from near a Pb-Zn mine (Kabwe, Zambia) and the capital city of Zambia (Lusaka). The concentrations of the seven metals and As in the soil samples and Pb in the rat tissue samples were quantified using atomic absorption spectroscopy. The concentrations of Pb, Zn, Cu, Cd, and As in Kabwe soil were much higher than benchmark values. Geographic Information System analysis indicated the source of metal pollution was mining and smelting activity. Interestingly, the area south of the mine was more highly contaminated even though the prevailing wind flow was westward. Wild rats from Kabwe had much higher tissue concentrations of Pb than those from Lusaka. Their body weight and renal Pb levels were negatively correlated, which suggests that mining activity might affect terrestrial animals in Kabwe. 相似文献
10.
Yoshiro Ono Hidehito Uemura Yoshinori Kanjo Osami Kawara Toshiki Ayano 《Journal of Material Cycles and Waste Management》2000,2(1):38-42
Construction waste such as road pavement and concrete is estimated to constitute about 50% of the total industrial waste in
Japan, and the recycling of such material has recently become a prominent topic among construction engineers. It has also
been suggested that various types of industrial waste be utilized as components of construction materials. This paper investigates
the environmental safety of certain materials in terms of the elutions and genotoxicities of these substances. The substances
extracted from some materials, such as emulsifier, ash, and sediment, were found to have genotoxic characteristics. The dose-related
responses of the various materials and their genotoxic strengths are shown.
Received: June 16, 1998 / Accepted: September 7, 1999 相似文献