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151.
The aim of this study was to determine the level of 26 polycyclic aromatic hydrocarbons (PAHs) at parking garages and to provide the necessary annual information based on occupational inhalation exposure and non-occupational inhalation exposure, which carry risks for the environment. For this purpose, 22 samples were collected continuously from both gas and particulates phase PAHs from two parking garages at Konya City Center, Turkey. The exposure-based risk of these samples was evaluated using concentrations of the carcinogenic PAH compounds. None of the 26 PAHs measured had values exceeding the recommended exposure limits (RELs) standard values for inhalation rate recommended by the World Health Organization (WHO). Exposure levels of gas and particulate PAHs for the occupational group and the public (children and adults who spend time in shopping centers) were found to be 0.07–28.24 μgm?3 and 0.05–5.753 μgm?3, respectively, representing levels two to four times higher than those at the control site. Maximum daily inhalation of B[a]Py was estimated at 1.33 ngd?1 for exposure of the public and as 274 ngd?1 for the occupational group. It is believed that traffic makes a substantial contribution to the PAH profile, which had relatively high concentrations of naphthalene (Napth) and coronene (Coro). Highly carcinogenic dibenzo(a,l)pyrene (B[al]Pyre) was found in the ambient air at two parking garages. Napth and phenanthrene (Phen) were the main compounds found in nearly all the tested samples. In this study, benzo[e]pyrene (B[e]Py) was used as a reference for PAHs because its concentration is stable and does not change seasonally. Considering the importance of these compounds in relation to human health, the aim of this work was to characterize and quantify the more toxic PAHs in parking garages. Conducting PAH sampling and their chemical analysis is very costly and labor intensive. This study produced data that can be a powerful tool for environmental forensics. 相似文献
152.
Distribution and sources of 16 parent polycyclic aromatic hydrocarbons (PAHs) were investigated in surface sediments from Port Dickson, Malaysia. Total PAHs varied from 481.3 to 976.6 with a mean value of 679.3 ng g?1 dry weight, which can be classified as moderate level of pollution. The toxic assessment suggested that the PAHs in sediments will not cause immediately adverse biological effects. Both petrogenic and pyrogenic PAHs were recorded in the study area with dominance of pyrogenic. The authors believe that effective monitoring and implementation of environmental regulations have resulted in a tremendous improvement of sediment quality in the Malaysian aquatic ecosystem. 相似文献
153.
K. Srogi 《Environmental Chemistry Letters》2007,5(4):169-195
Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic compounds with two or more fused aromatic rings. They
have a relatively low solubility in water, but are highly lipophilic. Most of the PAHs with low vapour pressure in the air
are adsorbed on particles. When dissolved in water or adsorbed on particulate matter, PAHs can undergo photodecomposition
when exposed to ultraviolet light from solar radiation. In the atmosphere, PAHs can react with pollutants such as ozone, nitrogen
oxides and sulfur dioxide, yielding diones, nitro- and dinitro-PAHs, and sulfonic acids, respectively. PAHs may also be degraded
by some microorganisms in the soil. PAHs are widespread environmental contaminants resulting from incomplete combustion of
organic materials. The occurrence is largely a result of anthropogenic emissions such as fossil fuel-burning, motor vehicle,
waste incinerator, oil refining, coke and asphalt production, and aluminum production, etc. PAHs have received increased attention
in recent years in air pollution studies because some of these compounds are highly carcinogenic or mutagenic. Eight PAHs
(Car-PAHs) typically considered as possible carcinogens are: benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene,
benzo(a)pyrene (B(a)P), dibenzo(a,h)anthracene, indeno(1,2,3-cd)pyrene and benzo(g,h,i)perylene. In particular, benzo(a)pyrene
has been identified as being highly carcinogenic. The US Environmental Protection Agency (EPA) has promulgated 16 unsubstituted
PAHs (EPA-PAH) as priority pollutants. Thus, exposure assessments of PAHs in the developing world are important. The scope
of this review will be to give an overview of PAH concentrations in various environmental samples and to discuss the advantages
and limitations of applying these parameters in the assessment of environmental risks in ecosystems and human health. As it
well known, there is an increasing trend to use the behavior of pollutants (i.e. bioaccumulation) as well as pollution-induced
biological and biochemical effects on human organisms to evaluate or predict the impact of chemicals on ecosystems. Emphasis
in this review will, therefore, be placed on the use of bioaccumulation and biomarker responses in air, soil, water and food,
as monitoring tools for the assessment of the risks and hazards of PAH concentrations for the ecosystem, as well as on its
limitations. 相似文献
154.
Summary. Individuals in an insect colony need to identify one another according to caste. Nothing is known about the sensory process
allowing nestmates to discriminate minute variations in the cuticular hydrocarbon mixture. The purpose of this study was to
attempt to model caste odors discrimination in four species of Reticulitermes termites for the first time by a non-linear mathematical approach using an "artificial neural network" (ANN). Several rounds
of testing were carried out using 1 – the whole hydrocarbon mixtures 2 – mixtures containing the hydrocarbons selected by
principal component analysis (PCA) as the most implicated in caste discrimination. Discrimination between worker and soldier
castes was tested in all four species. For two species we tested discrimination of four castes (workers, soldiers, nymphs,
neotenics). To test cuticular pattern similarity in two sibling species (R. santonensis and R. flavipes), we performed two experiments using one species for training and the other for query. Using whole hydrocarbons mixtures,
worker/soldier discrimination was always successful in all species. Network performance decreased with the number of hydrocarbons
used as inputs. Four-caste discrimination was less successful. In the experiment with the sibling species, the ANN was able
to distinguish soldiers but not workers. The results of this study suggest that non-linear mathematical analysis is a good
tool for classification of castes based on cuticular hydrocarbon mixture. In addition this study confirms that hydrocarbon
mixtures observed are real chemical entities and constitute a true chemical signature or odor. Whole mixtures are not always
necessary for discrimination.
Received 23 July 1998; accepted 9 October 1998. 相似文献
155.
复合人工湿地对有机污染物的去除效果初步研究 总被引:1,自引:0,他引:1
研究了由不同植物配置(驯化和未驯化)的两组下行和上行植物床组成的复合人工湿地对生活污水的净化效果。结果表明,CODCr和BOD5的去除率达67.3%,68.1%,总氮(TN)的去除率为26.9%,总磷(TP)的去除主要发生在上行床,去除率为81.6%。环芳烃(PAHs)中苊(Ace)、荧蒽(Flu)、芘(Py)、苯并[a]蒽(BaA)、屈(Chr)、苯并[b]荧蒽(BbF)、苯并[a]芘(BaP)、茚并[1,2,3-cd]芘(InP)和苯并[g,h,i](BPR)经下行床后,去除率超过80%,上行床去除较少。驯化床和未驯化床对PAHs的去除效果差异不显著。邻苯二甲酸酯(PAEs)中邻苯二甲酸二乙酯(DEP)和邻苯二甲酸二异丁酯(DiBP)经驯化床后,质量浓度显著升高,经未驯化床后邻苯二甲酸二(2-乙基)己酯(DEHP)含量显著降低。蚕豆根尖微核实验表明,不同植物配置对微核率影响差异并不显著,毒害物质经下行床后大部分被去除。 相似文献
156.
In ant societies, workers do not usually reproduce but gain indirect fitness benefits from raising related offspring produced
by the queen. One of the preconditions of this worker self-restraint is sufficient fertility of the queen. The queen is, therefore,
expected to signal her fertility. In Camponotus floridanus, workers can recognize the presence of a highly fertile queen via her eggs, which are marked with the queen's specific hydrocarbon
profile. If information on fertility is encoded in the hydrocarbon profile of eggs, we expect workers to be able to differentiate
between eggs from highly and weakly fertile queens. We found that workers discriminate between these eggs solely on the basis
of their hydrocarbon profiles which differ both qualitatively and quantitatively. This pattern is further supported by the
similarity of the egg profiles of workers and weakly fertile queens and the similar treatment of both kinds of eggs. Profiles
of queen eggs correspond to the cuticular hydrocarbon profiles of the respective queens. Changes in the cuticular profiles
are associated with the size of the colony the queen originates from and her current egg-laying rate. However, partial correlation
analysis indicates that only colony size predicts the cuticular profile. Colony size is a buffered indicator of queen fertility
as it is a consequence of queen productivity within a certain period of time, whereas daily egg-laying rate varies due to
cyclical oviposition. We conclude that surface hydrocarbons of eggs and the cuticular profiles of queens both signal queen
fertility, suggesting a major role of fertility signals in the regulation of reproduction in social insects. 相似文献
157.
158.
Abdallah Dahbi Alain Lenoir Alberto Tinaut Timo Taghizadeh Wittko Francke Abraham Hefetz 《Chemoecology》1996,7(4):163-171
Summary A comparative morphological and chemical study of six endemic species ofCataglyphis from the Iberian Peninsula:C. ibericus, C. rosenhaueri, C. hispanicus, C. humeya, C. velox andC. floricola and the Moroccan speciesC. bombycinus is described. The morphological study relied primarily on genitalia characteristics, whereas the chemical study concentrated on the postpharyngeal gland constituents. Cladograms based on the morphological and chemical data were performed using Ward's method. The dendrogram based on morphological features revealed that the IberianCataglyphis can be classified into three species groupsalbicans, altisquamis andemmae. The same pattern occurred when the dimethylalkanes constituents of the postpharyngeal gland were utilised as character states, with a slight displacement of species within thealtisquamis group. However, when the complete hydrocarbon blend was utilised major discrepancies in the dendrograms occurred.Cataglyphis velox proved to be very similar toC. bombycinus, whereasC. floricola clustered with the other two species of thealtisquamis group. Based on the geographical distribution and paleontological data (Tinaut 1993) it is assumed thatC. floricola recently invaded the Iberian Peninsula. Based on the chemical findings we postulate that chemical character displacement occurred inC. floricola as a result of its sympatry withC. velox after the former colonized the Iberian Peninsula. We further discuss the possible reason for the different dendrograms obtained when only the dimethylalkanes are considered and its implication for the communicative role of the postpharyngeal gland secretion in these ants. 相似文献
159.
土壤多环芳烃污染根际修复研究进展 总被引:13,自引:2,他引:13
多环芳烃(polycyclicaromatichydrocarbons,PAHs)是环境中普遍存在的具有代表性的一类重要持久性有机污染物,具“三致性”、难降解性,在土壤环境中不断积累,严重危害着土壤的生产和生态功能、农产品质量和人类健康。修复土壤多环芳烃污染已成为研究的焦点。根际修复是利用植物-微生物和根际环境降解有机污染物的复合生物修复技术,是目前最具潜力的土壤生物修复技术之一。对国内外学者近年来在土壤多环芳烃污染根际修复的效果、根际修复机理和根际修复的影响因素方面的研究进展作了较系统的综述,并分别分析了单作体系、混作体系、多进程根际修复系统和接种植物生长促进菌根际修复系统对土壤多环芳烃的修复效果。指出根际环境对PAHs的修复主要有3种机制:根系直接吸收和代谢PAHs;植物根系释放酶和分泌物去除PAHs,增加根际微生物数量,提高其活性,强化微生物群体降解PAHs。并讨论了影响根际修复PAHs的环境因素如植物、土壤类型、PAHs理化性质、菌根真菌以及表面活性剂等。植物-表面活性剂结合的根际修复技术、PAHs胁迫下根际的动态调节过程、运用分子生物学技术并结合植物根分泌物的特异性筛选高效修复植物以及植物富集的PAHs代谢产物进行跟踪与风险评价将成为未来研究的主流。 相似文献
160.
A review of the chemical ecology of the Cerambycidae (Coleoptera) 总被引:15,自引:0,他引:15
Summary. This review summarizes the literature related to
the chemical ecology of the Cerambycidae and provides a
brief overview of cerambycid biology, ecology, economic
significance, and management. Beetles in the family
Cerambycidae have assumed increasing prominence as pests
of forest and shade trees, shrubs, and raw wood products, and
as vectors of tree diseases. Exotic species associated with
solid wood packing materials have been notable tree killers
in North American urban and peri-urban forests. In forested
ecosystems native species respond to disturbances such as
fires and windstorms, and initiate the biodeterioration of
woody tissue. Eggs are laid by females, on or through the
bark surface of stem and branch tissue of moribund, recently
killed or decomposing woody plants; larval cerambycids
(roundheaded woodborers) typically feed in the phloem and
later in the xylem. Females will also, in some cases, select
living hosts, e.g. adult conifer and angiosperm trees, for
oviposition. Research on the chemical ecology of over 70
species has revealed many examples of attractive kairomones
(such as floral volatiles, smoke volatiles, trunk and leaf
volatiles, and bark beetle pheromones), repellents and
deterrents, oviposition stimulants, short- and long-range sex
pheromones, and defensive substances. Emerging generalities
are that attractants tend to be monoterpenoids and phenolic
esters; oviposition stimulants are monoterpenoids and
flavanoids; short-range sex pheromones are female-produced,
methyl-branched cuticular hydrocarbons; and
long-range sex pheromones are male-produced -hydroxy
ketones and (,)-diols ranging in length from 6 to 10 carbons.
The latter compounds appear to originate from glands
in the male thorax; putative defensive substances originate
from metasternal secretory pores or mandibular glands. In
one unusual case, a flightless, subterranean female that
attacks sugar cane produces a sex pheromone that is derived
from the amino acid isoleucine. With significantly more than
35,000 species of Cerambycidae worldwide, these generalities
will be subject to change as more species are examined.
Addendum
The authors would like to point out that the electronic version
is more accurate than the printed version. 相似文献