Higher Carbon Levels Research Articles

Eco-friendly innovation for nejayote coagulation–flocculation process using chitosan: Evaluation through zeta potential measurements

The main objective of the present paper is to discuss the convenience of using chitosan as a non-hazardous substance to improve the coagulation–flocculation (CF) efficiencies in nejayote (wastewater treatment containing high levels of total organic carbon, TOC=9836mg/L). For first time, two different molecular weight of chitosan in the wastewater treatment of the tortilla industry, were used as study models. The conditions here reported showed that both chitosans can be effectively used as adsorbent at pH 5.5 (mixing at 800rpm for 1min followed by a slow mixing at 200rpm for 5min) and at dosage of chitosan less than 3g/L for colloidal nejayote (without settleable solids). Both chitosan showed the highest performance under these conditions with more than 80% efficiency in turbidity removal, thus accomplishing the Mexican environmental regulation for free urban sewage discharge (NOM-002-SEMARNAT-1996). The zeta potential (ζ) of the nejayote supernatant before and after the CF treatment was used as a guiding parameter to evaluate each procedure. In addition, author suggest that the width of the flocculation window, for both chitosans in nejayote treatment, is attributed to their physical properties as molecular weight, deacetylation degree, dynamic viscosity and chemical properties as hydrogen bond, hydrophobicity and van der Waals interactions, as well as electrostatic forces that traditionally explain CF of colloids.

English

Soil attributes are an important tool to identify appropriate practices for crop management. This study aimed at evaluating physical, chemical and mineralogical properties of soil in agricultural uses, regarding its potential and/or restrictions in the municipality de Governador Dix-Sept Rosado (RN). Soil samples with deformed structure were collected with the aid of an auger Dutch-type zigzag layers in the 0.00-0.10; 0.10-0.20 and 0.20-0.30 m layers. Four composite soil samples, derived from 15 subsamples, were collected in: native forest (AMN), orchard cajaraneiras (AP), a traditional cropping area (AC), and an area of colluvium (ACOL). Samples were placed in plastic, bags identified and referred to the Laboratory Analysis of Soil and Plant Water LASAP/UFERSA. Subsequently, samples were air dried, broken into smaller pieces, and sieved through 2.0 mm mesh to obtain the dried soil air (TFSA) for physical, chemical and mineralogical analyzes. Results were submitted to Principal Component Analysis (Multivariate Statistics) to distinguish attributes in different agricultural uses. The first factor generated for soil properties in the areas surveyed explained 48.33% of the total variation in the studied area, and the highest correlation coefficients (≥ |70|) identified were the variables: sand, silt, pH, Ca2+, H+Al, SB, T, T, V in the layer 0.00-0.10 m. These variables are probably influenced by the source material, and consequently the management practices adopted in farming areas. Primary minerals type 2:1 such as illite and mica in the horizon A and the horizon Bi predominated in diffraction peaks of X-ray, which can be justified by the presence of clay minerals in the clay fraction, young soil characteristics and limited weathering. Properties differed between areas, and presented physical limitations on the soil resistance to penetration, and have excellent chemical characteristics such as high levels of exchangeable calcium and total organic carbon. Key words: Mineralogical analysis, diffraction, environment, different management.

Pre-Cenozoic geology of the Latrobe Valley Area—onshore Gippsland Basin, S.E. Australia

In 2010–2011, a well on the uplifted northern edge of the Latrobe Valley (Yallourn North-1A) cored a 550 m section of mostly arenaceous sediments from the Lower Cretaceous Tyers River Subgroup. A follow-up core-hole (Yallourn Power-1) aimed at extending the Tyers River Subgroup section some 5 km south into the Latrobe Valley instead encountered Paleozoic basement rocks immediately below Cenozoic coal measures. From a re-examination of earlier coal and groundwater bore results, and new interpretations from gravity, seismic and magneto-telluric (MT) surveys, there is a significant area of Paleozoic basement rock that may underlie the whole northern Latrobe Valley area. The uplifted Yallourn North Lower Cretaceous sediments are a separate basin entity herein named the Monash trough. It appears they are separate from the main Lower Cretaceous Strzelecki Group Basin sediments on the southern side of the Latrobe Valley. Attributes of the Monash trough may underlie the main Strzelecki Basin, but this remains to be substantiated by further drilling. The intervening subcrop of Paleozoic basement rocks is herein named the Glengarry basement block. It shows characteristic gravity, MT and seismic features covering some 200 km2 of the northern Latrobe Valley area. The boundary between the Glengarry basement block and Strzelecki Basin approximates to the Princes Highway. It is uncertain whether structural separation of the Monash trough from the main Strzelecki Basin always existed, or whether uplift and stripping of Cretaceous rocks over the Glengarry basement block occurred in post-Cretaceous but pre-Cenozoic times. Comparative rank and maturity indices indicate a greater depth of burial of the Glengarry basement block than what exists today, whereas less stripping and loss of section have occurred to the Monash trough. Cretaceous sediments of the Tyers River Subgroup (Rintouls Creek Formation, Tyers Conglomerate) in the Monash trough are dominated by mudstones, siltstones with lesser quartzose sandstones, conglomerates and thin coals. The sediments are over 300 m thick and are conformably overlain by 100 m of volcaniclastic sediments typical of the main Strzelecki Group, in turn overlain by nearly 100 m of Cenozoic coal measures. New detailed spore–pollen dating of Yallourn North-1A cores indicates that all Cretaceous sediments in the Monash trough are Barremian in age. This revises the traditional Neocomian age assigned to the formation. High total organic carbon levels in the 100 m-thick mudstones of the Locmany Member in the Rintouls Creek Formation constitute a mature petroleum source rock worthy of future hydrocarbon exploration.

Soil based nutrient management plan for Onattukara sandy tract of Kerala

The present investigation was carried out at College of Agriculture, Vellayani, Kerala Agricultural University, Kerala to develop the nutrient management strategies for Onattukara sandy tract of Kerala. The overall fertility status of this region indicated that the soil was strongly acidic with high level of phosphorus and low organic carbon and potassium. Excess levels of phosphorus and wide spread deficiencies of calcium, magnesium boron and zinc are the major limitations to crop production in this region. Management of soil acidity is essential for successful crop production in the region. Liming of acid soils in accordance with soil test results is highly essential. Regular application of organic matter or recycling of organic matter is essential to maintain favourable physico-chemical and biological environment in the soils and retention of applied plant nutrients. Restrict the use of nitrogenous (N) fertilizers in accordance with soil test results or as recommended in the package of practices of Kerala Agricultural University. Reduction in the use of phosphatic (P) fertilizers to the tune of fifty per cent of the recommended dose is possible. Apply potassium (K) fertilizers in doses specified, but in several splits to minimize the leaching losses. Amelioration of soil acidity and external inputs of secondary and micronutrients along with the NPK nutrients are essential for enhancing crop productivity in the region.

Record high global atmospheric carbon levels recorded

Record high global atmospheric carbon levels recorded

Resource conservation strategies for rice‐wheat cropping systems on partially reclaimed sodic soils of the Indo‐Gangetic region, and their effects on soil carbon

AbstractThe Indo‐Gangetic plain is characterized by intensive agriculture, largely by resource‐poor small and marginal farmers. Vast swathes of salt‐affected areas in the region provide both challenges and opportunities to bolster food security and sequester carbon after reclamation. Sustainable management of reclaimed soils via resource conservation strategies, such as residue retention, is key to the prosperity of the farmer, as well as increases the efficiency of expensive initiatives to further reclaim sodic land areas, which currently lay barren. After five years of experimentation on resource conservation strategies for rice‐wheat systems on partially reclaimed sodic soils of the Indo‐Gangetic region, we evaluated changes in different soil carbon pools and crop yield. Out of all resource conservation techniques which were tested, rice‐wheat crop residue addition (30% of total production) was most effective in increasing soil organic carbon (SOC). In rice, without crop residue addition (WCR), soils under zero‐tillage with transplanting, summer ploughing with transplanting and direct seeding with brown manuring showed a significant increase in SOC over the control (puddling in rice, conventional tillage in wheat). In these treatments relatively higher levels of carbon were attained in all aggregate fractions compared to the control. Soil aggregate sizes in meso (0.25‐2.0 mm) and macro (2‐8 mm) ranges increased, whereas micro (< 0.25 mm) fractions decreased in soils under zero‐till practices, both with and without crop residue addition. Direct seeding with brown manuring and zero tillage with transplanting also showed an increase of 135% and 95%, respectively, over the control in microbial biomass carbon, without crop residue incorporation. In zero tillage with transplanting treatment, both with and without crop residue showed significant increase in soil carbon sequestration potential. Though the changes in accrued soil carbon did not bring about significant differences in terms of grain yield, overall synthesis in terms of balance between yield and carbon sequestration indicated that summer ploughing with transplanting and zero tillage with transplanting sequestered significantly higher rates of carbon, yet yielded on par with conventional practices. These could be appropriate alternatives to immediately replace conventional tillage and planting practices for rice‐wheat cropping systems in the sodic soils of the Indo‐Gangetic region.

Transverse Creep of Nickel-Base Superalloy Bicrystals

A liquid metal cooled (LMC) solidification technique was used to produce nickel-base GTD 444 and Rene N4 superalloy bicrystals with varying degrees of misorientation. Creep experiments with loading normal to the bicrystal boundaries were conducted at 1255 K (982 °C). Despite the similar overall compositions of these two alloys, the GTD 444 alloy with higher levels of carbon and boron displayed significantly higher tolerance to high-angle boundaries. Creep ductilities at rupture of greater than 5 pct were observed in GTD444 for boundaries misoriented by greater than 20 deg. Electron backscatter diffraction analysis showed significant lattice rotation adjacent to the bicrystal boundary in GTD444. In contrast, the Rene N4 bicrystal accumulated damage along the grain boundary early in creep, failing at less than 2 pct strain.

Preliminary investigation to characterize deposits forming during combustion of biogas from anaerobic digesters and landfills

The objectives of this study were to compare composition and morphological characteristics of the deposits forming in engines operated with biogas from anaerobic digesters and from landfills. Engine deposit samples were collected from biogas to energy facilities in Florida, USA. The deposit samples were analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Similarities and differences between the deposit samples collected from the engines operated with biogas from anaerobic digesters and biogas from landfills were analyzed in terms of chemical composition and morphology. The sample obtained from the anaerobic digester gas did not contain potassium while calcium and zinc were present at a higher ratio. Relatively high levels of carbon were present in the crystalline deposits forming during the combustion of biogas. C:O:Si ratios were about 5:7:1 in the deposits obtained from the engines operated with biogas from the anaerobic digesters and 2:3.5:1 in the deposits from the engines operated with landfill gas. In general, the silicon content from deposits found in facilities utilizing biogas from anaerobic digesters was lower than those operated with landfills gas. The difference was made up with higher phosphorus, sulfur and calcium content in the deposits from the engines operated with digester gas.

The rare earth element geochemistry of surface sediments in four transects in the South China Sea and its geological significance

Seventy-five samples of surface sediment were collected from four transects in the South China Sea (SCS) for analyses of rare earth element (REE) geochemistry. Total REE abundance (∑REE) in the SCS varies from 45 to 195 ppm (average 128 ppm), lower than that of the upper continental crust. The spatial distribution of REE is strongly dependent upon the geographical location and depositional environment. Low ΣREE concentrations are observed on the continental slope (e.g., Xisha and Nansha islands), while high ΣREE concentrations are present in the deep basin. Sediments on the slope are also characterized by lower LREE/HREE, (La/Yb)N, Eu/Eu*, and Ce/Ce* ratios relative to deep-basin sediments. There is a positive correlation between Al2O3 and ΣREE, and a negative correlation between CaO and ΣREE. Conversely, the relatively insignificant Fe–Mn oxide accumulation in the SCS suggests that manganese nodules do not make a significant contribution to the bulk REE composition of sediments. Therefore, the sediment REE geochemistry is mainly controlled by terrigenous and biogenic sources. Biogenic carbonate has a diluting effect on ΣREE concentrations, but a significant influence on LREE/HREE, Ce/Ce*, and (La/Yb)N values is found only in sediments with especially high biogenic carbonate levels. The REE geochemistry of SCS surface sediments indicates that their source is mainly post-Archean felsic rocks. In the eastern sub-basin, the relatively low LREE/HREE ratios and high Eu/Eu* values of the sediments indicate that significant terrigenous materials are derived from young volcanic rocks (e.g., rocks in the Luzon arc).

Characteristics and Fertilizer Effects of Soil‐Like Materials from Landfill Mining

Landfills stock massive amounts of minerals and materials, where soil‐like material is the primary component of stored waste in old landfills. A typical old landfill (Yingchun landfill) in China was taken as a study case. The stored wastes were sampled from different depths of the landfill, and then the soil‐like materials were screened for further analysis. Physicochemical characteristics and the fertilizer quality of the soil‐like materials were analyzed and the fertilizer effects were studied by cultivatingImpatiens balsaminaL. with different mixed ratios of soil‐like materials and natural soils. According to the results, soil‐like materials accounted for 75.02% of the total stored wastes and were in an advanced state of decomposition. Soil‐like materials displayed a cation exchange capacity of 84.53 cmol(+) kg−1, pH 8.14, and an electrical conductivity of 1190.55 μS cm−1, and were also characterized by high levels of organic carbon and nutrient contents compared to natural soils. The total organic carbon, total nitrogen, total phosphorus, and total potassium of soil‐like materials were 9.06, 0.16, 0.21, and 1.48%, respectively. Most of the heavy metal content was relatively lower than the law limits in China. However, As and Zn may have an environmental contamination risk. It could be shown that soil‐like materials could significantly promote growing and flowering ofI. balsaminaL., and were proved to be a valuable bio‐resource with utility as soil amendment, cultivating substrate, and raw materials for producing organic–inorganic compound fertilizers.

Development of carbon composite iron ore micropellets by using the microfines of iron ore and carbon-bearing materials in iron making

Iron ore microfines and concentrate have very limited uses in sintering processes. They are used in pelletization; however, this process is cost intensive. Furthermore, the microfines of non-coking coal and other carbon-bearing materials, e.g., blast-furnace flue dust (BFD) and coke fines, are not used extensively in the metallurgical industry because of operational difficulties and handling problems. In the present work, to utilize these microfines, coal composite iron oxide micropellets (2–6 mm in size) were produced through an innovative technique in which lime and molasses were used as binding materials in the micropellets. The micropellets were subsequently treated with CO2 or the industrial waste gas to induce the chemical bond formation. The results show that, at a very high carbon level of 22wt% (38wt% coal), the cold crushing strength and abrasion index of the micropellets are 2.5–3 kg/cm2 and 5wt%–9wt%, respectively; these values indicate that the pellets are suitable for cold handling. The developed micropellets have strong potential as a heat source in smelting reduction in iron making and sintering to reduce coke breeze. The micropellets produced with BFD and coke fines (8wt%–12wt%) were used in iron ore sintering and were observed to reduce the coke breeze consumption by 3%–4%. The quality of the produced sinter was at par with that of the conventional blast-furnace sinter.

100 Years of superphosphate addition to pasture in an acid soil—current nutrient status and future management

Pasture-based animal production systems, which occupy a significant proportion of the landscape in Victoria, Australia, have historically been nutrient-limited, with phosphorus (P) often the most limiting nutrient. The Permanent Top-Dressed (PTD) pasture experiment was established in 1914 at the Rutherglen Research Station, Victoria, to investigate the management of this deficiency. The main objective of the PTD experiment was to demonstrate the value of adding P fertiliser at two rates to increase pasture productivity for lamb and wool production. We report on the status of the PTD soils after 100 years, investigating the long-term implications of continuous grazing and fertiliser management (0, 125 and 250 kg/ha of superphosphate every second year) of non-disturbed pasture. We investigated the long-term effects of P fertiliser on the forms and distribution of P and other relevant soil parameters. In the fertilised treatments, P has accumulated in the surface soils (0–10 cm) as both orthophosphate and organic P, with an Olsen P of 16–21 mg P/kg, which is non-limiting for pasture production. In the treatment with 250 kg superphosphate, there has also been movement of P down through the soil profile, probably due to the high sand content of the surface soil and the transfer through the profile of small quantities of water-soluble P and P bound to organic ligands. Over time, the site has continued to acidify (surface 0–10 cm); the soil acidity combined with aluminium (Al) concentrations in the fertilised treatments approach a level that should impact on production and where broadcast lime would be recommended. After 100 years of non-disturbed pasture, the surface soils of these systems would be in a state of quasi-equilibrium, in which the fertilised systems have high levels of carbon (C), nitrogen, P and exchangeable Al. The continued stability of this system is likely dependent upon maintaining the high C status, which is important to nutrient cycling and the prevention of Al phytotoxicity. There are two risks to this system: (i) the declining pH; and (ii) soil disturbance, which may disrupt the equilibrium of these soils and the bio-chemical processes that maintain it.

Organic carbon, and major and trace element dynamic and fate in a large river subjected to poorly-regulated urban and industrial pressures (Sebou River, Morocco)

An annual-basis study of the impacts of the anthropogenic inputs from Fez urban area on the water geochemistry of the Sebou and Fez Rivers was conducted mostly focusing on base flow conditions, in addition to the sampling of industrial wastewater characteristic of the various pressures in the studied environment. The measured trace metals dissolved/particulate partitioning was compared to the ones predicted using the WHAM-VII chemical speciation code. The Sebou River, upstream from Fez city, showed a weakly polluted status. Contrarily, high levels of major ions, organic carbon and trace metals were encountered in the Fez River and the Sebou River downstream the Fez inputs, due to the discharge of urban and industrial untreated and hugely polluted wastewaters. Trace metals were especially enriched in particles with levels even exceeding those recorded in surface sediments. The first group of elements (Al, Fe, Mn, Ti, U and V) showed strong inter-relationships, impoverishment in Fez particles/sediments and stable partition coefficient (Kd), linked to their lithogenic origin from Sebou watershed erosion. Conversely, most of the studied trace metals/metalloids, originated from anthropogenic sources, underwent significant changes of Kd and behaved non-conservatively in the Sebou/Fez water mixing. Dissolved/particulate partitioning was correctly assessed by WHAM-VII modeling for Cu, Pb and Zn, depicting significant differences in chemical speciation in the Fez River when compared to that in the Sebou River. The results of this study demonstrated that a lack of compliance in environmental regulations certainly explained this poor status.

Steels with High Temperature Carbides - New Possibilities for Semi-Solid State Processing

Semi-solid processing of steels is typically studied using high-alloy steels with higher carbon levels, as those offer a long freezing range which is favourable for conducting the process. The drawback to their application is their microstructure which typically consists of austenite grains embedded in ledeburitic network. This type of microstructure typically fails in brittle manner by fracturing along the interface of the hard network and ductile austenite grains. This is why a way was sought to altering or even inverting the configuration of the microstructure. Eventually, suitable steel chemistries were found which allow the inverted microstructure to be obtained. With regard to the high content of alloy additions, these steels have to be made by powder metallurgy methods. Five different steels of this kind were selected for the experimental programme. All contained high amounts of alloying elements and a large fraction of carbides. Their carbon content was taken into account as well, ranging from 0.55 to 3.4 %. Differences between the steels consisted in the levels of major alloying elements, namely chromium, vanadium, molybdenum, tungsten and cobalt. After suitable process parameters were found, semi-solid processing was used to prepare demonstration products. The transition through semi-solid state transformed the ferritic matrix to austenitic-martensitic one, in which the high-stability carbides were retained. The resulting microstructures were of unconventional nature where carbide particles were embedded in tough metal matrix. Their configuration was thus inverted in contrast to the ones typically obtained by semi-solid processing of tool steels.

Increasing native microbiota in lignocellulosic waste composting: Effects on process efficiency and final product maturity

Intensive agriculture produces more than one million tons of organic waste mainly composed of lignocellulosic compounds. Though some management strategies have been lately adopted, many problems related to time and surface required for a proper treatment and final product quality remain unsolved. In this work, a staggered bioaugmentation process is proposed for the improvement of horticultural waste composting. Inocula were composed of 30 microbial strains previously isolated from identical composting piles, operated under the same conditions used in this work. The high levels of biomass carbon at the beginning of the bio-oxidative phase and the parallel evolution of reducing sugars reflected a quick adaptation of microbial inocula to the high temperatures reached during the process. Reducing sugar content during the process in the uninoculated pile was below 200μgg−1, while a higher content was detected in the inoculated pile (2500μgg−1). Hemicellulose degraded at the end of the process in the inoculated pile was near to 85% whereas in the control pile was below 70%. Lignin degradation ratio was also higher in the inoculated pile (41% in comparison to 23% in the control pile). Moreover, several stabilization and humification indices supported that the bio-inoculation procedure here reported yields better quality products, earlier stabilized, from processes in which lignocellulosic carbon is more efficiently biotransformed.

بررسی بیان ژن های طویل ساز گونه Mortirella alpine در شرایط مناسب تولید آراشیدونیک اسید و روغن

بررسی بیان ژن های طویل ساز گونه Mortirella alpine در شرایط مناسب تولید آراشیدونیک اسید و روغن

Microstructural characterization of low and high carbon CoCrMo alloy nanoparticles produced by mechanical milling

CoCrMo alloys are utilised as the main material in hip prostheses. The link between this type of hip prosthesis and chronic pain remains unclear. Studies suggest that wear debris generated in-vivo may be related to post-operative complications such as inflammation. These alloys can contain different amounts of carbon, which improves the mechanical properties of the alloy. However, the formation of carbides could become sites that initiate corrosion, releasing ions and/or particles into the human body. This study analysed the mechanical milling of alloys containing both high and low carbon levels in relevant biological media, as an alternative route to generate wear debris. The results show that low carbon alloys produce significantly more nanoparticles than high carbon alloys. During the milling process, strain induces an fcc to hcp phase transformation. Evidence for cobalt and molybdenum dissolution in the presence of serum was confirmed by ICP-MS and TEM EDX techniques.

Semi-Solid Processing of Powder Steels in Cryogenically-Cooled Die

By processing steels in the semi-solid state it is possible to achieve unconventional structures even with commonly used steels. This can be demonstrated on X210Cr12 tool steel. After semi-solid state processing, 96% of the microstructure can consist of metastable austenite. In the microstructure, there are polyhedral grains embedded in a ledeburitic network. A combination of semi-solid state processing and rapid solidification is a new method for modifying the microstructure more substantially. In the present experiment, two tool steels, CPM 15V and CPM S30V, were processed by an unconventional method. Since the steels are made by powder metallurgy, their initial structure contains globular carbides in ferritic matrix. Both materials have high levels of carbon and alloying elements, namely vanadium and chromium. The unconventional processing was carried out by mini-thixoforming which enables the use of a small amount of metal. After heating into the semi-solid region, the material was rapidly forced by lateral extrusion into a cavity of a metal die where rapid solidification and rapid cooling took place. Two cooling schedules were employed. In the first case, the die was at room temperature, whereas in the second one it was pre-cooled to-196°C using liquid nitrogen. Since the test sample was cooled from both sides and its thickness was 3 mm, immensely high cooling rates were achieved. The influence of the cooling rate was also noticeable in the microstructures containing high fractions of metastable austenite, martensite and carbides.

Pyrolysis of agricultural residues for bio-oil production

The production of biofuel from biomass waste is of great interest to the scientific community regarding the discovery of solutions to global energy demand and global warming. The pyrolysis of biomass to produce bio-oil is an easy, cheap and promising technology. In the current investigation, the pyrolysis of two different biomasses (cornelian cherry stones and grape seeds) was achieved at temperatures ranging from 300 to 700 °C. The effect of pyrolysis temperatures on the yields of each product was significant. The bio-oil yields were maximized at 500 °C for cornelian cherry stones and 700 °C for grape seeds. The compositions of bio-oils for both cornelian cherry stones and grape seeds were similar and contained mainly oxygenated hydrocarbons. The compounds observed in this investigation were composed of phenols, alkyl benzenes, alkanes, alkenes, fatty acids, fatty acid esters and a few nitrogen-containing compounds. Bio-char properties were amended in association with both the pyrolysis temperature and biomass type. Bio-chars from cornelian cherry stones contained higher carbon and lower oxygen levels than those from grape seeds under identical conditions. Increases in pyrolysis temperatures produced bio-chars containing higher carbon levels and heating values for both carnelian cherry stones and grape seeds.

Personal Black Carbon Exposure Influences Ambulatory Blood Pressure

Few prospective studies have assessed the blood pressure effect of extremely high air pollution encountered in Asia’s megacities. The objective of this study was to evaluate the association between combustion-related air pollution with ambulatory blood pressure and autonomic function. During February to July 2012, personal black carbon was determined for 5 consecutive days using microaethalometers in patients with metabolic syndrome in Beijing, China. Simultaneous ambient fine particulate matter concentration was obtained from the Beijing Municipal Environmental Monitoring Center and the US Embassy. Twenty-four–hour ambulatory blood pressure and heart rate variability were measured from day 4. Arterial stiffness and endothelial function were obtained at the end of day 5. For statistical analysis, we used generalized additive mixed models for repeated outcomes and generalized linear models for single/summary outcomes. Mean (SD) of personal black carbon and fine particulate matter during 24 hours was 4.66 (2.89) and 64.2 (36.9) μg/m 3 . Exposure to high levels of black carbon in the preceding hours was associated significantly with adverse cardiovascular responses. A unit increase in personal black carbon during the previous 10 hours was associated with an increase in systolic blood pressure of 0.53 mm Hg and diastolic blood pressure of 0.37 mm Hg (95% confidence interval, 0.17–0.89 and 0.10–0.65 mm Hg, respectively), a percentage change in low frequency to high frequency ratio of 5.11 and mean interbeat interval of −0.06 (95% confidence interval, 0.62–9.60 and −0.11 to −0.01, respectively). These findings highlight the public health effect of air pollution and the importance of reducing air pollution.