the future of ecological risk assessment

... exposure at the top of the list of health risks, with hazardous waste sites near the bottom (USEPA 1987b, 1989) Nonetheless, the amount of resources devoted to these two problems reflect the public ... is inserted into the headspace above the blood sample and the VOCs bind to the phase on the outside of the fiber shaft This fiber is then inserted into the GC inlet, the VOCs are thermally desorbed, ... the study Only 13 of the VOCs originally present in the first days of the study continued to be emitted in the final days, indicating that these 13 were the only true components of the materials This...

Ngày tải lên: 12/08/2014, 00:21

... ppb for smokers) The effect of benzene exposure on the general population at current levels of exposure is not known The health effects of benzene at the levels found among the Churchill County ... large U.S study, 95% of the participants in the study had an ethylbenzene concentration up to 0.25 parts per billion in their blood The effect of ethylbenzene exposure on the general population ... U.S study, 95% of the participants had a styrene concentration up to 0.18 parts per billion in their blood The effect of styrene exposure on the general population at current levels of exposure...

Ngày tải lên: 14/02/2014, 03:20

... primarily because of the previously reported occurrence of some of these compounds in many of the Nation’s water supplies.(3, 7, 8, 9, 10) The overall intent of the Program’s VOC assessment is to ... studies This is the first national assessment of the occurrence of a large number of VOCs with different uses, and the assessment addresses key questions about VOCs in aquifers The assessment also ... hydrocarbons The detection frequencies of most VOCs were dependent on the dissolved-oxygen conditions of ground water and the type of VOC The ratios of the detection frequencies of 10 frequently...

Ngày tải lên: 14/03/2014, 19:20

... apply to the determination of the composition or concentration of fragrance components in products 1.4 The term “Executive Officer” as used in this document means the Executive Officer of the Air ... between the results of Method 310 and the supplied formulation data, then the results of Method 310 shall take precedence over the supplied formulation data The results of Method 310 shall then ... to meet the applicable VOC standards, then no enforcement action for violation of the VOC standards will be taken 3.7.2 If the Executive Officer is unable to verify the accuracy of the supplied...

Ngày tải lên: 14/03/2014, 20:20

... corresponds to the wind direction plot for this source The red × at the center of the blue area is the sampling site of the reasons why isoprene and M87 occur in the same source The KD value of this ... (highway 225 is just to the north and highway 146 to the east and southeast of the sampling site) This can be another cause of the shape of the wind directional plot There are many peaks almost ... corresponds to the wind direction plot for this source The red × at the center of the blue area is the sampling site FIGURE 14 Location of propene The circles denote the propene emitters The blue area...

Ngày tải lên: 22/03/2014, 14:20

... cases the quality of the indicators depends on the degree of association between the indicator and either the exposure or the target response variable This association between the indicator and the ... extraction of the trapped VOCs from the sorbent and injection of an aliquot of the extract into a gas chromatograph (GC) and (ii) thermal elution of adsorbed VOCs from the sorbent by means of a pure ... and the "one response factor" approaches They defined the TVOC value as the sum of the identified VOCs plus the amount obtained by applying to the non-identified peaks in the chromatogram the...

Ngày tải lên: 28/03/2014, 19:20

... results of a MOZART simulation of the CO outflow from the city Superimposed on the plume are flight tracks from the G1 on 18th March and from the C130 on 19th March The points of interception of the ... month of March 2006, at 3:00 PM, local time Shown to the right of each bar graph is a breakdown, for T0, T1 and the C130, respectively, for all of the species measured in terms of the sums of the ... interception of the plume at a lower altitude upon return into the MCMA The higher mixing ratios of MTBE at the beginning and the end of the flights were obtained during transects over the city In...

Ngày tải lên: 28/03/2014, 20:20

... limit their widespread application We selected 13 VOCs from the chromatographic profile of exhaled breath on the basis of the detectability of the peak and their biological significance, ten of ... COPD, all of whom were diagnosed on the basis of the GOLD guidelines [13] In brief, the entry criteria, consisted of a post-bronchodilator FEV1 of

Ngày tải lên: 12/08/2014, 18:21

... dung dịch natri thioasenat xảy sau : H2S + Na4As2S5O2 = Na4As2S5O + H2O -Tiếp theo , natri thioasenat hoàn nguyên theo phản ứng : 2Na4As2S6O + O2 = 2Na4As2S5O2 + 2S -Hai phản ứng xảy nhanh phản ... lại chu trình để kết hợp với CO2 H2O có khí thải tạo thành amin cacbonat phản ứng tiếp tục xảy theo sơ đồ hệ thống xử lí khí H2S amoni cacbonat Sơ đồ hệ thống xử lý H2S amoni cacbonat Trong ... thùng rửa máy lọc li tâm b Công nghệ xử lí H2S NaOH -Cơ sở phương pháp khí H2S kết hợp với NaOH theo phản ứng sau đây: H2S + NaOH = Na2S + 2H2O Na2S + H2S = 2NaHS Na2S + H2O = NaHS + NaOH -Song...

Ngày tải lên: 12/04/2015, 14:24

... diphenyl ethers (PBDEs) These compounds were measured in maternal tissues, and the phenomenon of transplacental transfer of these xenobiotics from mothers to their progeny was investigated The potential ... for the nursing mothers to eliminate lipophilic toxins Depuration of POPs via breast milk could confer the baby with approximately 20% of the mother’s lifelong burden of pesticides over the first ... north of the equator at the southern tip of the Malaysian peninsula with Indonesia to the southwest (Figure 2-2) This strategic geographical location has led Singapore to become one of the 18...

Ngày tải lên: 14/09/2015, 14:06

... optical characteristics of the dye will alter the transmission of the light [22] The sensitivity depends on several parameters, mainly both the chemical properties of the dye and the light propagation; ... syndrome, and the presence of VOCs is taken into account in all theories, so its detection and control are very important to handle with the SBS cause of the presence of some gases [9]; they can be ... group of environmental factors [6] One of the most popular theories for some years was that the main SBS source was the effect of several VOCs present at low concentrations that, all together,...

Ngày tải lên: 14/03/2014, 20:20

Ngày tải lên: 28/03/2014, 20:20

... used: Water Workshop of the Powder Adhesive Surface: 34 m2 Number of workers: Number of stations: - Filling of the machine of conditioning of the powder adhesive - Conditioning of the powder adhesive ... Workshop of the solvented Adhesive Page of Workshop of the Natural Adhesive Surface: 129.37 m2 Number of workers: Number of stations: - Manufacture of the Natural adhesive - Conditioning of Natural ... of the buildings, ) and regarding the nature of solvents used; (iii) a retrospective assessment, with the chemical engineer of the company, of the evolution of the solvents’ compositions and quantities...

Ngày tải lên: 20/06/2014, 00:20

... capacity of refuse, Lo, depends on the type of refuse present in the landfill For example, the higher the cellulose contents of the refuse, the higher the value of Lo The values of the theoretical ... respectively The number of Monte Carlo terms chosen was based on the level of uncertainty believed to exist in the values of the uncertain parameters In Figure 3, the range of values of the age of the ... simulation, the original values of the uncertain parameters used in the deterministic mode were assumed to be representative of the mean value of the parameters, with the range of values of the parameters...

Ngày tải lên: 05/09/2013, 16:11

... some of the weaknesses and problems that can affect the quality of studies investigating the potential causes of cryptorchidism and hypospadias Quality assessment of the various studies and of the ... Kortenkamp 2008), the most important being that risk assessment of anti-androgenic ECs for humans has to consider not the toxicity and level of exposure of the individual ECs, but the sum of exposure ... limitations on the scope of this review Two overviews are used to set the scene for the review First, an assessment of the latest evidence on the prevalence of human TDS disorders and whether this...

Ngày tải lên: 13/02/2014, 10:20

... for the adsorbate, and 1/n is a function of the strength of adsorption For fixed values of Ce and 1/n, the larger the value of K, the larger the capacity qe For fixed values of K and Ce , the ... depends upon the strength of adsorption of the competing molecules, the concentrations of these molecules, and the type of activated carbon Some examples illustrate the possible magnitude of the competitive ... smaller the value of 1/n, the stronger is the adsorption bond.As 1/n becomes very small, the capacity tends to be independent of Ce and the isotherm plot approaches the horizontal level; the value of...

Ngày tải lên: 14/02/2014, 03:20

... Furthermore, the dependency of spatial distribution of leaves on the basal area of individuals, and the nonlinearity of the Guenther et al (1993) algorithms, introduce nonlinearities into the ... in the Southern Appalachians and the Pinelands of the southeastern coastal plain (Pines tend to emit monoterpenes) Between the mid-1980s and the mid-1990s, there were systematic increases in the ... for each of the strata The second source of uncertainty can be quantified directly from the FIA data by calculating the sample variance for each of the stratum means The first source of uncertainty,...

Ngày tải lên: 14/02/2014, 08:20

... Hydrocarbons - The Alkanes The names of the alkanes are derived from the Greek prefix for the particular number of carbon atoms in the compound with an -ane ending The names of the first ten alkanes ... RCR (The oxygen is bonded to a carbon atom in the middle of the chain) Naming of Ketones: Number the- longest carbon chain starting so that the –C=O group is attached to the carbon atom with the ... contain the structure: OH Ethers Functional Group: O General formula: ROR Naming of ethers Ethers are commonly named by naming each group attached to the oxygen followed by the word ether If...

Ngày tải lên: 14/02/2014, 08:20

... Flanges and Other Connections For welded flanges, place the probe at the outer edge of the flangegasket interface and sample the circumference of the flange 1161 Sample other types of nonpermanent ... source of leaks from valves is the seal between the stem and housing Place the probe at the interface where the stem exits the packing gland and sample the stem circumference Also, place the probe ... 6.2 The instrument shall be capable of measuring the leak definition concentration specified in the regulation 1155 6.3 The scale of the instrument meter shall be readable to ±2.5 percent of the...

Ngày tải lên: 14/02/2014, 08:20

... with the emission spectrum of any UV source, calculation of the erythemal output of this source Sources of natural and artificial UV radiation Solar radiation The sun is the main source of exposure ... selection biases at the inception of the cohort Taken together, the four case–control studies selected and the prospective study offer the conclusion that the increased melanoma risk was associated ... an indication of non-significant effect was given, a relative risk of and a standard error equal to the mean standard error of the other studies was considered The pooled relative risks did not...

Ngày tải lên: 14/02/2014, 21:20