Benzene Research Papers - Academia.edu (original) (raw)

Phenol is one of the most important intermediate for petrochemical, agrochemical, and plastics industries<em>. </em>Almost<em> 95% phenol is </em>produced using cumene method. Cumene method is a multi-stage process... more

Phenol is one of the most important intermediate for petrochemical, agrochemical, and plastics industries<em>. </em>Almost<em> 95% phenol is </em>produced using cumene method. Cumene method is a multi-stage process with many disadvantages including the difficulties to gain phenol product in maximum quantities and production of co-product such as acetone which has great amount in market nowadays. One of the alternative routes to produce phenol which has more advantages is through benzene hydroxylation reaction using H<sub>2</sub>O<sub>2</sub> as oxidant agent and Titanium Silikalit-1 (TS-1) as catalyst. TS-1 catalyst has high catalytic activity and selectivity in selective oxidation reaction of aromatic compounds with H2O2 which important for commercial industries. However, the reaction rate is tend to be low because TS-1 has hydrophobic nature and as the result H2O2 adsorption which has hydrophilic nature towards active sites of TS-1 i...

Water wells (n = 116) overlying the Eagle Ford, Fayetteville, and Haynesville Shale hydrocarbon production areas were sampled for chemical, isotopic, and groundwater-age tracers to investigate the occurrence and sources of selected... more

Water wells (n = 116) overlying the Eagle Ford, Fayetteville, and Haynesville Shale hydrocarbon production areas were sampled for chemical, isotopic, and groundwater-age tracers to investigate the occurrence and sources of selected hydrocarbons in groundwater. Methane isotopes and hydrocarbon gas compositions indicate most of the methane in the wells was biogenic and produced by the CO2 reduction pathway, not from thermogenic shale gas. Two samples contained methane from the fermentation pathway that could be associated with hydrocarbon degradation based on their co-occurrence with hydrocarbons such as ethylbenzene and butane. Benzene was detected at low concentrations (<0.15 μg/L), but relatively high frequencies (2.4-13.3% of samples), in the study areas. Eight of nine samples containing benzene had groundwater ages >2500 years, indicating the benzene was from subsurface sources such as natural hydrocarbon migration or leaking hydrocarbon wells. One sample contained benzene ...

The estimated incidence of acute promyelocytic leukemia (APL) is approximately 6 cases per 10 million people per year with no apparent differences between sexes. The age of APL cases is younger than that of other acute myeloid leukemias... more

The estimated incidence of acute promyelocytic leukemia (APL) is approximately 6 cases per 10 million people per year with no apparent differences between sexes. The age of APL cases is younger than that of other acute myeloid leukemias (AML). Spatial and temporal clusters of APL have been reported. These observations suggest a possible selective role for environmental and/or occupational factors in APL development. A multicenter case-control study was carried out on risk factors for acute leukemias and preleukemias. In this report data related to APL are selectively analyzed from the larger study to identify specific risk factors. The case-control study on 38 cases of APL showed a strong association with shoemaking (odds ration 6.3, 95% confidence interval 1.3-31.1). A moderate leukemogenic effect from living in houses built with tuff, a polous building material containing gamma-emitting radionuclides and having a high radon concentration, and from using hair dyes was also suggeste...

Implications Benzene and particulate matter monitoring during the Deepwater Horizon oil spill revealed that ambient air quality was a likely threat to public health and that residents in coastal Louisiana experienced significantly greater... more

Implications Benzene and particulate matter monitoring during the Deepwater Horizon oil spill revealed that ambient air quality was a likely threat to public health and that residents in coastal Louisiana experienced significantly greater exposures than urban residents. Threshold air pollution levels established for the oil spill apparently were not used as a basis for informing the public about these potential health impacts. Also, despite carrying out the most comprehensive air monitoring ever conducted in the region, none of the agencies involved provided integrated analysis of the data or conclusive statements about public health risk. Better information about real-time risk is needed in future environmental disasters.

Risk estimates and cause and effect determinations are directly dependent on exposure and dose-response relationships. Recently, relative risks and excess cancer mortality attributed to occupational benzene exposure have been published in... more

Risk estimates and cause and effect determinations are directly dependent on exposure and dose-response relationships. Recently, relative risks and excess cancer mortality attributed to occupational benzene exposure have been published in collaborative studies conducted by Chinese investigators and scientists from the National Cancer Institute. The results of these studies suggest increased risk of acute nonlymphocytic leukemia at relatively low benzene concentrations and associations with cancers not previously associated with benzene exposure. These studies are potentially important due to their size and potential to more thoroughly investigate the link between benzene exposure and cancer. However, there are questions concerning the validity of exposure and dose estimates supporting relative risk characterizations in these studies. Apparent discrepancies between modeled exposure and dose estimates and sources of actual measured exposure information and clinical markers of benzene toxicity raise serious concerns questioning the reliability of relative risk and cancer associations stated in these studies.

Penggunaan lem pada industri sepatu kemungkinan memberikan dampak kesehatan terhadap pekerja karena lem biasanya mengandung bahan berbahaya, seperti benzena dan toluena. Pemerintah sudah berupaya membuat kebijakan untuk mengendalikan... more

Penggunaan lem pada industri sepatu kemungkinan memberikan dampak kesehatan terhadap pekerja karena lem biasanya mengandung bahan berbahaya, seperti benzena dan toluena. Pemerintah sudah berupaya membuat kebijakan untuk mengendalikan penyakit akibat kerja, salah satunya adalah mengurangi pajanan bahan kimia berbahaya. Penelitian ini bertujuan untuk mengetahui dampak kesehatan akibat pajanan benzena dan toluena yang berasal dari penggunaan lem di tempat kerja di sentra industri sepatu Ciomas, Bogor pada tahun 2017. Desain penelitian adalah potong lintang dengan variabel kandungan benzena dan toluena di udara ruang kerja, kandungan S-PMA dalam urin, dan gangguan kesehatan yang dialami oleh pekerja. Jumlah sampel pekerja sebanyak 34 orang yang berasal dari 5 bengkel kerja. Analisis data dilakukan secara deskriptif. Hasil penelitian menunjukkan bahwa kadar benzena dan toluena dalam lem masing-masing adalah 0,1% dan 55%, kadar uap benzena di udara ruang kerja berada di bawah limit deteksi alat (tidak terdeteksi), dan rerata kandungan S-PMA dalam urin adalah 0,24 µg/g kreatinin. Tidak terjadi pajanan benzena terhadap pekerja industri sepatu di lokasi penelitian. Perilaku berisiko pekerja dengan persentase cukup tinggi adalah merokok, penggunaan APD, dan cuci tangan. Keluhan/gangguan kesehatan yang dirasakan (lebih dari 60%) adalah cepat lelah, sakit kepala, kesemutan. Perlu perbaikan lingkungan kerja yang lebih sehat dan nyaman, dan mengedukasi pekerja untuk menggunakan APD.

Several iron complexes [FeII(bpy)22+, FeII(OPPh3)42+, and FeII(PA)2] in combination with hydrogen peroxide (HOOH) catalytically hydroxylate aromatic substrates (ArH). The base-induced nucleophilic addition of HOOH to the electrophilic... more

Several iron complexes [FeII(bpy)22+, FeII(OPPh3)42+, and FeII(PA)2] in combination with hydrogen peroxide (HOOH) catalytically hydroxylate aromatic substrates (ArH). The base-induced nucleophilic addition of HOOH to the electrophilic iron center yields the reactive intermediate of Fenton reagents . The latter includes a ‘stabilized’ hydroxyl radical that is able to replace an aromatic hydrogen (H) with a hydroxyl group (HO) via an initial addition reaction. With PhCH3 and PhCH2CH3 as substrates free HO· (from the radiolysis of H2O) reacts via aryl addition (97 and 85%, respectively) to give Ar-Ar as the predominant product, whereas 1 favors H-atom abstraction from the alkyl group (50 and 80%, respectively) and the only detectable products from aryl addition are the respective substituted phenols (o:p-ArOH). Other substituted benzenes (PhX) undergo addition by free HO at the ortho and para aryl carbons (o:p ratio, 2), followed by dimerization and elimination of two H2O molecules to yield substituted biphenyls. In contrast, 1 reacts with PhX to yield substituted phenol (ArOH; o:p ratio, 0.5 – 1.1). With phenol (PhOH) as the substrate, reaction with 1 yields mainly catechol (o-Ar(OH)2; o:p ratio, 20). In a solvent matrix of MeCN:H2O (3:1 mol:mol ratio) the reaction efficiencies with FeII(bpy)22+ and FeII(OPPh3)42+ for the hydroxylation of benzene to phenol are 36 and 42%, respectively (product per HOOH).Iron(II) complexes [FeIILx2+; FEII(bpy)22+, FeII(OPPh3)42+, FeII(PA)2 (PAH = picolinic acid)] catalytically activate hydrogen peroxide via Fenton chemistry for the hydroxylation of aromatic molecules (PhX).

This report provides an overview of ambient air quality trends in Kolkata from 2002 to 2015 based on monitoring data collected by West Bengal Pollution Control Board regarding ambient air quality during this time period on Carbon... more

This report provides an overview of ambient air quality trends in Kolkata from 2002 to 2015 based on monitoring data collected by West Bengal Pollution Control Board regarding ambient air quality during this time period on Carbon Monoxide, Sulphur Dioxide, Nitrogen Dioxide, Ozone. Particulate Matter – PM 10 & PM 2.5, Benzene, and heavy Metals like Lead & nickel. Time series air quality concentrations are presented as a set of indicators, which compare measured concentrations with air quality standards.