Reporting the Presence of Coronary Artery Calcium in the Final Impression of Non-gated CT Chest Scans Increases the Appropriate Utilization of Statins.

Background Coronary artery calcium (CAC) scoring based on gated non-contrast cardiac computed tomography (CT) is a validated risk marker of major adverse cardiovascular events (MACE). Reporting of CAC on non-gated CT chest (NGCT) scans and the impact on medical therapy is not well studied. Methods A retrospective cohort of 5,043 NGCT scans was reviewed for the presence of CAC. The radiology report was reviewed to determine whether CAC was mentioned in either the body of the report or the final impression. Electronic medical records (EMR) were abstracted for baseline demographics, cardiovascular (CV) risk factors, lipid-lowering agents, and aspirin (ASA) prior to and after NGCT. Results CAC was present in 63.0% of NGCT scans. Of these scans, CAC was mentioned in the body of the report in 81.6% of studies. Conversely, CAC was mentioned in the final impressions in only 15.1% of these scans. Amongst patients with CAC, initiation of a statin in treatment-naive patients was more common when CAC was mentioned in the final impression versus the body only (12.3% vs. 4.9%, p=0.001) despite the fact that baseline utilization of statins in this cohort was higher (71.1% vs. 64.1%, p=0.005). Initiation of a statin in treatment-naive patients had a trend towards significance when CAC was mentioned in the body of the report versus not reported (4.9% vs. 2.62%, p=0.142). Reporting of CAC in the final impression significantly increased the initiation of ASA in treatment-naive patients (9.52% vs. 4.33%, p=0.033). Reporting of CAC in either the final impression or the body of the report did not affect the initiation of non-statin lipid-lowering therapies in patients with CAC. Conclusion The inclusion of CAC in the final impression of NGCT radiology reports positively impacts the appropriate initiation of statin and aspirin therapy in treatment-naive patients. Universal adherence to a standardized reporting system for the presence of CAC on NGCT should be considered to improve the initiation of guideline-directed medical therapy.

Characterisation of thiocyanate degradation in a mixed culture activated sludge process treating coke wastewater.

Microbial degradation of thiocyanate (SCN-) has been reported to suffer from instability highlighting the need for improved understanding of underlying mechanisms and boundaries. Respirometry, batch tests and DNA sequencing analysis were used to improve understanding of a mixed culture treating coke wastewater rich in SCN-. An uncultured species of Thiobacillus was the most abundant species (26%) and displayed similar metabolic capabilities to Thiobacillus denitrificans and Thiobacillus thioparus. Thiocyanate was hydrolysed/oxidised to NH4+-N, HCO3- and SO42-. Nevertheless, at 360-2100 mg SCN-/L a breakdown in the degradation pathway was observed. Respirometry tests demonstrated that NH4+-N was inhibitory to SCN- degradation (IC50: 316 mg/L). Likewise, phenol (180 mg/L) and hydroxylamine (0.25-16 mg/L) reduced SCN- degradation by 41% and ca. 7%, respectively. The understanding of the SCN- degradation pathways can enable stable treatment efficiencies and compliance with effluent of <4 mg SCN/L, required by the Industrial Emissions Directive.

Preemptive Tecovirimat Use in an Active Duty Service Member Who Presented With Acute Myeloid Leukemia After Smallpox Vaccination.

Smallpox vaccine is contraindicated in immunosuppression due to increased risk for adverse reactions (eg, progressive vaccinia). We describe the first-ever use of tecovirimat as a preemptive vaccinia virus treatment strategy during induction chemotherapy in an active duty service member who presented with acute leukemia and inadvertent autoinoculation after smallpox vaccination.

Incidence and Implication of Coronary Artery Calcium on Non-gated Chest Computed Tomography Scans: A Large Observational Cohort.

Introduction  Coronary artery calcification (CAC) scoring is typically performed utilizing non-contrast, electrocardiogram- (ECG) gated CT and offers an estimation of cardiovascular (CV) prognosis and risk stratification beyond previously established cardiac risk factors. Coronary calcification can also be assessed during non-gated chest CT, which is significant given the recent recommendations for lung cancer screening by low-dose CT. Methods We retrospectively reviewed 4,953 non-contrast chest CT scans in a single, closed referral tertiary military treatment facility over an 18-month period. Baseline CV outcomes to include myocardial infarction (MI), cerebral vascular accidents (CVA), revascularization with percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG), death, or a composite of all major adverse cardiac events (MACE), and baseline CV risk factors were abstracted from an electronic medical record (EMR) review. Results CAC was seen in 3,119 (63%) patients while 1,834 (27%) were without CAC. All traditional CV risk factors were more commonly observed in patients with CAC. Unadjusted odds of composite MACE, death, MI, coronary revascularization, and CVA between presence and absence of CAC were as follows: 3.55 [95% confidence interval (CI): 2.60-4.86, p: <0.0001]; 2.98 (95% CI: 2.02-4.40, p: <0.0001); 24.42 (95% CI: 3.36-177.6, p: <0.0001); 5.64 (95% CI: 2.58-12.32, p: <0.0001); and 2.32 (95% CI: 1.19-4.50, p: 0.0104), respectively. However, after adjusting for baseline risk factors, CAC on non-gated CT was associated only with an increased observed rate of MI (aOR: 38.1, 95% CI: 4.57-318.2, p: <0.0001) and revascularization (aOR: 5.58, 95% CI: 2.22-14.0, p; 0.0003). Conclusions Findings of CAC on non-gated chest CT may help to recognize patients who are at increased risk of MI and revascularization. Given the expected increase in chest CT utilization among former smokers for lung cancer screening, observed CAC should be reported to ordering providers in order to identify patients at increased risk of these important outcomes.

Critical Care in the Military Health System: A 24-h Point Prevalence Study.

Background: Healthcare expenditures are a significant economic cost with critical care services constituting one of its largest components. The Military Health System (MHS) is the largest, global healthcare system of its kind. In this project, we sought to describe critical care services and the patients who receive them in the MHS. Methods: We surveyed 26 military treatment facilities (MTFs) representing 38 critical care services or intensive care units (ICUs). MTFs with multiple ICUs and critical care services responded to the survey as services (e.g., surgical or medical ICU service), whereas MTFs with only one ICU responded as a unit and gave information about all types of patients (i.e., medical and surgical). Our survey was divided into an administrative portion and a 24-h point prevalence survey of patients and patient care. The administrative portion is reported separately in this journal. The 24-h point prevalence survey collected information about all patients present in, admitted to, or discharged from participating services/units during the same 24-h period in December 2014. The survey was anonymous and protected health information was not collected. Findings: Sixteen MTFs (69%) and 27 ICU services/units (71%) returned the point prevalence survey. MTFs with >200 beds (n = 3, 22%) were categorized as "high capacity centers" (HCCs) whereas those with ≤200 beds (n = 13, 78%) were characterized as low capacity centers (LCCs). Two MTFs (one HCC and one LCC) returned only administrative data. The remaining 16 MTFs reported data about 151 patients. In all, 100 (67%) of the patients were at three HCCs during this study period. One HCC accounted for 39% (59 patients) of all patient care during this study. Most patients were cared for in mixed medical/surgical ICUs (34.4%), followed by medical (21.2%), surgical (18.5%), trauma (11.9%), cardiac (7.9%), and burn (6.0%) ICUs. The most common medical indication for admission was cardiac followed by general medical. The most common surgical indications for admission were trauma, other, and cardiothoracic surgery. The average APACHE II score of all patients across both LCCs and HCCs was 11 ± 8.1 (8 ± 7.8 vs. 13 ± 7.7 p = 0.008). The lower acuity of patients in this study is reflected in a high turnover rate, low rate of arterial and central line placements (33%), and low rates of life support (all types, 30%; mechanical ventilation only, 21.2%; noninvasive mechanic ventilation only, 7.9%; and vasoactive medications, 6.6%). Thirty-five (23.2%) patients within the study were affected by a total of 57 complications. The three most common complications experienced were acute kidney injury, bleeding, and sepsis. Discussion: This is the first detailed report about MHS critical care services and the patients receiving care. It describes a low acuity ICU patient population, concentrated at larger MTFs. This study highlights the need for the establishment of a system that allows for the continuous collection of high priority information about clinical care in the MHS in order to facilitate implementation of standardized protocols and process improvements.

Alkalinity and external carbon requirements for denitrification-nitrification of coke wastewater.

The Industrial Emissions Directive requires that coke wastewater is treated to reach an effluent with < 50 mg/L total nitrogen (TN). A shortage of alkalinity (3.6 mg as CaCO3/mg [Formula: see text]) in the wastewater limited nitrification to 45%. Various compounds were tested as a source of additional alkalinity, with optimal results being found for sodium carbonate, which enabled 95% nitrification at 300 mg/L (as CaCO3). Sodium bicarbonate led to incomplete ammonia oxidation (76%) whilst soda ash prevented nitrite oxidation. Addition of sodium hydroxide enabled 98% nitrification but was associated with [Formula: see text] accumulation. Ammonia and nitrite oxidation had optimal pH ranges of 7.0-8.3 and 5.5-6.8, respectively. As organic carbon concentrations in coke wastewater are at times insufficient for effective denitrification external organic carbon was also considered to enhance denitrification. A laboratory-scale anoxic-aerobic activated sludge process was used to investigate glycerol and acetic acid as carbon sources. Glycerol was associated with a low biomass production (0.18 mg of biomass produced per 1 mg of glycerol) and mixed liquor suspended solids (MLSS) declined from 2235 to 750 mg/L leading to incomplete nitrification (< 30%) and an effluent TN of 59 mg/L. Acetic acid had a higher biomass production (0.31 mg of biomass produced per 1 mg of acetic acid) maintaining stable MLSS concentrations (3137 mg/L). Overall, a denitrification-nitrification process with alkalinity (Na2CO3 at 300 mg/L) and acetic acid dosing enabled an effluent TN of 24 mg/L.

How Many Transgender Men Are There in San Francisco?

The purpose of this study was to estimate the number of transgender men (transmen) adults living in San Francisco. We integrated two population size estimation methods into a community-based health survey of transmen (n = 122) in the San Francisco Bay Area in 2014-2015: the service multiplier and wisdom of the crowds. The median estimate was 806 transmen adults in San Francisco (0.11% of adults) and 4027 in the Bay Area. Considering potential biases, we believe our estimates are conservative. Knowing the denominator of persons at risk for health conditions is necessary for public health planning, surveillance, and impact evaluation.

Dose assessment from chronic exposure to industrial NORM in iron ore processing.

Radiological exposures due to naturally occurring radioactive material (NORM) can occur during a wide range of work-related activities in the mineral processing and chemical industries. However, evaluation of such exposures in industrial settings remains a difficult exercise owing inter alia to the large number of personnel, operations and plants affected; assumptions that often have to be made concerning the actual duration and frequency of exposures; the complex chemistry and radioactive disequilibria involved and typically, the paucity of historical data. In our study, the challenges associated with assessing chronic exposure to fugitive dust enriched in 210Pb and 210Po and the determination of the associated internal dose by inhalation and ingestion are described by reference to a case study undertaken at an iron ore sintering plant between June 2013 and July 2015. The applicability of default dose coefficients and biokinetic models provided by the International Commission for Radiological Protection (ICRP) was verified by combining air and dust monitoring with information on the characteristics of the aerosols and in-vitro solubility experiments. The disparity between particulate matter 100 microns or less in diameter (PM100), particulate matter 10 microns or less in diameter (PM10) and 210Pb/210Po activity concentrations observed over the different monitoring campaigns and sampling locations confirmed that use of positional short-term monitoring surveys to extrapolate intake over a year was not appropriate and could lead to unrealistic intake and dose figures. Personal air sampling is more appropriate for estimating the dose in such situations, though it is not always practical and may collect insufficient quantities of material for radiochemical analysis; this is an important constraint when dealing with low specific activity materials.

Dose assessment from chronic exposure to industrial NORM in iron ore processing.

Radiological exposures due to naturally occurring radioactive material (NORM) can occur during a wide range of work-related activities in the mineral processing and chemical industries. However, evaluation of such exposures in industrial settings remains a difficult exercise owing inter alia to the large number of personnel, operations and plants affected; assumptions that often have to be made concerning the actual duration and frequency of exposures; the complex chemistry and radioactive disequilibria involved and typically, the paucity of historical data. In our study, the challenges associated with assessing chronic exposure to fugitive dust enriched in 210Pb and 210Po and the determination of the associated internal dose by inhalation and ingestion are described by reference to a case study undertaken at an iron ore sintering plant between June 2013 and July 2015. The applicability of default dose coefficients and biokinetic models provided by the International Commission for Radiological Protection was verified by combining air and dust monitoring with information on the characteristics of the aerosols and in-vitro solubility experiments. The disparity between particulate matter 100 microns or less in diameter (PM100), particulate matter 10 microns or less in diameter (PM10) and 210Pb/210Po activity concentrations observed over the different monitoring campaigns and sampling locations confirmed that use positional short-term monitoring surveys to extrapolate intake over a year was not appropriate and could lead to unrealistic intake and dose figures. Personal air sampling is more appropriate for estimating the dose in such situations, though it is not always practical and may collect insufficient quantities of material for radiochemical analysis; this is an important constraint when dealing with low specific activity materials.

Prevalence of HIV and Associated Risk Factors Among Long Distance Truck Drivers in Inchope, Mozambique, 2012.

This is the first integrated biological and behavioral surveillance survey among long-distance truck drivers (LDTD) in Mozambique. Using modified time-location sampling in 2012 at a key transportation junction (Inchope), we enrolled 327 male LDTD. HIV prevalence was 15.4 % (95 % confidence interval : 11.4-19.4 %, n = 318 tested). Among HIV-positive LDTD, 83.7 % did not know their status. One-third of LDTD had never tested for HIV and three-quarters had not received free condoms, lubricants or HIV literature in the past 12 months. In that same period, 61.4 % of LDTD had at least four sexual partners and 27.1 % paid for sex. Among sexually-active LDTD, 76.5 % did not use a condom at last sex. HIV was associated (p < 0.05) with primary education or lower (AOR 2.1), residence in Mozambique (AOR 2.3) and never having tested for HIV (AOR 2.2). Our findings reveal that broader coverage of HIV prevention and comprehensive care services for LDTD are urgently needed.

High Burden of HIV Infection and Risk Behaviors Among Female Sex Workers in Three Main Urban Areas of Mozambique.

This is the first integrated biological and behavioral survey among female sex workers (FSW) in Mozambique. Using respondent-driven sampling, 400, 411 and 429 FSW were enrolled respectively in Maputo, Beira and Nampula in 2011-2012. Estimates were produced using RDSAT 7.1. HIV prevalence was 31.2, 23.6, and 17.8 % in each location respectively. Among HIV-positive FSW, 48.1, 79.8 and 89.6 % in each city, were unaware of their serostatus. Condom use at last sex with a client was 85.8, 73.4 and 62.8 % among FSW, respectively. HIV was associated with current age, age of first sex for money, low educational level, and having had a genital ulcer in the last 6 months. Results suggest the urgent need to increase behavioral and structural interventions in this key population.

Critique and lessons learned from using multiple methods to estimate population size of men who have sex with men in Ghana.

Population size estimation of key populations at risk of HIV is essential to every national response. We implemented population size estimation of men who have sex with men (MSM) in Ghana using a three-stage approach within the 2011 Ghana Men's Study: during the study's formative assessment, the larger integrated bio-behavioral surveillance (IBBS) survey; and during the stakeholder meeting. We used six methods in combination within the three-stage approach (literature review, mapping with census, unique object multiplier, service multiplier, wisdom of the crowd, and modified Delphi) to generate size estimates from 16 locations (4 IBBS survey sites and 12 other locations) and used the estimates from the 16 sites to extrapolate the total MSM population size of Ghana. We estimated the number of MSM in Ghana to be 30,579 with a plausible range of 21,645-34,470. The overall estimate suggests that the prevalence of MSM in Ghana is 0.48 % of the adult male population. Lessons learned are shared to inform and improve applications of the methods in future studies.

Men who have sex with men in Mozambique: identifying a hidden population at high-risk for HIV.

The population of men who have sex with men (MSM) has been largely ignored in HIV-related policies and programming in Mozambique and there is little information about the contribution of MSM to the HIV epidemic. An integrated biological and behavioral study among MSM using respondent-driven sampling was conducted in 2011 in Maputo, Beira and Nampula/Nacala. Men who reported engaging in oral or anal sex with other men in the last 12 months answered a questionnaire and provided a blood sample for HIV testing. The prevalence of HIV was 8.2 % (Maputo, n = 496), 9.1 % (Beira, n = 584) and 3.1 % (Nampula/Nacala, n = 353). Prevalence was higher among MSM ≥ 25 vs. 18-24 years: 33.8 % vs. 2.4 % (p < 0.001), 32.1 vs. 2.8 % (p < 0.001), and 10.3 vs. 2.7 % (p < 0.06), in each city respectively. The difference in prevalence demonstrates the need to increase prevention for younger MSM at risk for HIV and ensure care and treatment for older HIV-infected MSM.

Prevalence of HIV, sexually transmitted infections, and risk behaviours among female sex workers in Nairobi, Kenya: results of a respondent driven sampling study.

We conducted a respondent driven sampling survey to estimate HIV prevalence and risk behavior among female sex workers (FSWs) in Nairobi, Kenya. Women aged 18 years and older who reported selling sex to a man at least once in the past 3 months were eligible to participate. Consenting FSWs completed a behavioral questionnaire and were tested for HIV and sexually transmitted infections (STIs). Adjusted population-based prevalence and 95 % confidence intervals (CI) were estimated using RDS analysis tool. Factors significantly associated with HIV infection were assessed using log-binomial regression analysis. A total of 596 eligible participants were included in the analysis. Overall HIV prevalence was 29.5 % (95 % CI 24.7-34.9). Median age was 30 years (IQR 25-38 years); median duration of sex work was 12 years (IQR 8-17 years). The most frequent client-seeking venues were bars (76.6 %) and roadsides (29.3 %). The median number of clients per week was seven (IQR 4-18 clients). HIV testing was high with 86.6 % reported ever been tested for HIV and, of these, 63.1 % testing within the past 12 months. Of all women, 59.7 % perceived themselves at 'great risk' for HIV infection. Of HIV-positive women, 51.0 % were aware of their infection. In multivariable analysis, increasing age, inconsistent condom use with paying clients, and use of a male condom as a method of contraception were independently associated with unrecognized HIV infection. Prevalence among STIs was low, ranging from 0.9 % for syphilis, 1.1 % for gonorrhea, and 3.1 % for Chlamydia. The data suggest high prevalence of HIV among FSWs in Nairobi. Targeted and routine HIV and STI combination prevention strategies need to be scaled up or established to meet the needs of this population.

How can we improve online HIV and STD prevention for men who have sex with men? Perspectives of hook-up website owners, website users, and HIV/STD directors.

Internet-based interventions have potential to reduce HIV and STD transmission among men who meet male sexual partners online. From November 2009 to May 2010 we surveyed dating and hook-up website users (n = 3,050), website owners (n = 18), and health department HIV/STD directors (n = 81) to identify structural and behavioral prevention interventions that could be implemented online and which a majority of website users were willing to use, owners were willing to implement, and HIV/STD directors perceived to be effective. A majority of each of the three stakeholder groups agreed on the following: (1) automated HIV/STD testing reminders, (2) local STD test site directories, (3) links to sex-positive safe sex videos, (4) access to sexual health experts, (5) profile options to include safer sex preference, (6) chat rooms for specific sexual interests, (7) filtering partners by their profile information, and (8) anonymous e-card partner notification for STD exposure. Findings help build consensus about how to prioritize resources for implementing online HIV and STD prevention interventions and highlight differences between stakeholders to guide future discussion about how to advance prevention efforts.

Assessment of exposure to PCDD/F, PCB, and PAH at a basic oxygen Steelmaking (BOS) and an iron ore sintering plant in the UK.

An assessment was carried out at a UK integrated steelworks to investigate the exposure of workers via inhalation to dioxins [polychlorinated dibenzo-p-dioxins (PCDD/F)], polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAH) including benzo[a]pyrene (B[a]P). Investigations focused on a basic oxygen steelmaking (BOS) plant and an iron ore sintering plant. The highest concentrations of PCDD/F and dioxin-like PCB were found at the BOS vessels and sinter strand area at the BOS and sinter plant, respectively. A risk assessment was carried out by comparing the daily intake of PCDD/F and PCB via inhalation with the recommended tolerable daily intake (TDI) proposed by the World Health Organisation (WHO). For the most exposed category of worker in this study (i.e. sinter plant workers inside the strand area), the estimated daily intake via inhalation was estimated to be 0.25 pg WHO-toxic equivalent concentrations (TEQ) kg(-1) body weight (bw). Considering that the average UK adult exposure to PCDD/F from the diet is 1.8 pg WHO-TEQ kg(-1) bw day(-1), the results indicated that the estimated daily intake of PCDD/F and PCB via inhalation for sinter plant workers would not result in the recommended range of the TDI (1-4 pg WHO-TEQ kg(-1) bw day(-1)) being exceeded. Cancer risks for a 40-year occupational exposure period were determined by multiplying the estimated intake by the inhalation cancer potency factor for 2,3,7,8-tetrachlorodibenzo-p-dioxin. For the most exposed category of worker, cancer risks from exposure to PCDD/F and PCB ranged from 2.5 × 10(-6) to 5.2 × 10(-5). Under most regulatory programmes, excess cancer risks between 1.0 × 10(-6) and 1.0 × 10(-4) indicate an acceptable range of cancer risk, suggesting a limited risk from PCDD/F and PCB exposure for workers in the sinter plant. With regard to PAH, B[a]P concentrations were typically <10 ng m(-3) at all locations at both the sinter plant and the BOS plant. In several cases, particularly at the sinter plant, B[a]P concentrations were well below or only marginally above the target value of 1 ng m(-3) specified in ambient air by the European Commission in the fourth 'Daughter' Directive of the Air Quality Framework Directive suggesting a very low risk of exposure for workers. For PAH, excess cancer risks ranged from 2.4 × 10(-6) to 7.3 × 10(-6) for BOS plant workers and from for 5.3 × 10(-7) to 1.5 × 10(-5) for sinter plant workers, well within the acceptable range proposed by the US EPA.

Exposure assessment of workers to airborne PCDD/Fs, PCBs and PAHs at an electric arc furnace steelmaking plant in the UK.

Occupational exposure studies were undertaken at a UK electric arc furnace (EAF) steelmaking plant to investigate the exposure of workers via inhalation to dioxins, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) including benzo[a]pyrene (B[a]P). Surveys were undertaken in areas including the melting shop, the casting department and a furnace control cabin. The highest concentrations of dioxins and PCBs were found inside the melting shop nearby EAFs, whereas dioxin and PCB concentrations in the casting department and inside the control cabin were significantly lower. Risk characterization was carried out by comparing the daily intake of dioxins and PCBs through inhalation with the recommended tolerable daily intake (TDI). Health risk assessments were also carried out by combining exposure data with inhalation cancer potency factors to quantify the cancer risk. For the most exposed category of workers (melting shop workers), the estimated daily intake via inhalation was 0.35 pg WHO-TEQ kg(-1) body weight (bw) in the worst case scenario. Considering that the average UK adult exposure to dioxins from the diet is 1.8 pg WHO-TEQ kg(-1) bw day(-1), the results indicated that the estimated daily intake of dioxins via inhalation at the EAF would not result in the recommended range of the TDI (1-4 pg WHO-TEQ kg(-1) bw day(-1)) being exceeded. Cancer risks for a 40-year occupational exposure period were determined by multiplying the inhalation dose by the inhalation cancer potency factor for 2,3,7,8-tetrachlorodibenzo-p-dioxin. For melting shop workers, cancer risks from exposure to dioxins and PCBs ranged from 2.05 x 10(-5) to 7.54 x 10(-5). Under most regulatory programmes, excess cancer risks between 1.0 x 10(-4) and 1.0 x 10(-6) indicate an acceptable range of excess cancer risk, suggesting a limited risk from dioxin exposure for workers in the EAF plant. For the calculation of excess cancer risks, no account has been taken of the protection provided by protective respiratory equipment worn by EAF workers. If personal protective equipments were taken into consideration, it is likely that the excess cancer risks for EAF workers would have been lower and considered as negligible. The highest concentrations of PAHs were found in the melting shop and the casting areas of the plant. In the melting shop area, B[a]P concentrations ranged from 1.4 to 24.5 ng m(-3), with a mean value of 7 ng m(-3). No workplace exposure limits have been published by the Health and Safety Executive in the UK for PAHs; however, the B[a]P concentrations found were below the limit value of 150 ng m(-3) (8-h time-weighted average) specified for workplace exposure in France. Exposure assessment of workers to PAHs via inhalation was carried out by calculating a potential cancer risk considering a 40-year occupational exposure period and B[a]Peq concentrations. Estimated cancer risks for the most exposed category of workers (i.e. melting shop workers) ranged from 3.66 x 10(-6) to 1.64 x 10(-5). The cancer risks determined in this study were well within an acceptable range of excess cancer risk of 1.0 x 10(-4) to 1.0 x 10(-6), specified by the US Environmental Protection Agency.

Removal of vapour phase PCDD/Fs in electric arc furnace steelmaking emissions by sorption using plastics.

Plastics are potentially suitable for the removal of vapour phase PCDD/Fs in emissions from the electric arc furnace (EAF) steelmaking process. Three different commercial plastics, i.e. polypropylene BE170MO (Borealis A/S, Denmark), polypropylene in the form of 5 mm spheres (The Precision Plastic Ball Co. Ltd., UK) and polyethylene LD605BA (ExxonMobil Chemical, Belgium), have been studied using a novel experimental apparatus for the removal of vapour phase PCDD/Fs. Polypropylene BE170MO was identified to be the most suitable product amongst the three plastics in terms of PCDD/F sorption and potential industrial application. The optimum temperature for PCDD/F sorption on polypropylene BE170MO was below 90 degrees C for a removal efficiency of >99% at an average vapour phase PCDD/F concentration of 3.5 ng I-TEQ/Nm(3). At 130 degrees C, 53% of the PCDD/Fs trapped on polypropylene BE170MO were desorbed.

PCDD/F and "Dioxin-like" PCB emissions from iron ore sintering plants in the UK.

Investigations have been carried out at the three Corus UK sinter plants over the period 2002-2004 to characterise the emissions of both 2,3,7,8-PCDD/Fs and WHO-12 PCBs, to estimate annual mass releases of these organic micro-pollutants using the I-TEF and WHO-TEF schemes, and to investigate the formation of PCBs in the iron ore sintering process. Results showed that the sintering of iron ore produces a characteristic WHO-12 PCB and PCDD/F congener pattern that is substantially the same for all UK sinter plants. With regard to WHO-12 PCBs, the most abundant congeners were typically PCBs 118 (6-9 ngNm(-3)), 105 (2-4 ngNm(-3)) and 77 (2-3 ngNm(-3)). All other WHO-12 PCBs were also detected at concentrations around 1 ngNm(-3). All sinter plants investigated exhibited very similar TEQ concentrations. WHO-12 PCB emissions were in the range 0.042-0.111 ngWHO-TEQNm(-3), whereas PCDD/F emissions ranged from 0.39 to 1.62 ngWHO-TEQNm(-3). PCDF congeners were the main contributors to the overall TEQ in sintering emissions (ca. 85%). Amongst WHO-12 PCBs, PCB 126 was the only noteworthy contributor to total TEQ (ca. 5-7%), a similar contribution to that from PCDDs. Based on the measurements that Corus UK has undertaken at these three sinter plants, annual mass releases of WHO-12 PCBs and PCDD/Fs have been calculated. For UK sinter plants, a total mass release of 29.5 g WHO-TEQ per annum [WHO-12 PCBs+PCDD/Fs] has been estimated, representing 9% of the total PCDD/F emissions to the UK atmosphere. Measurements were also carried out at a UK sinter plant to determine the windleg emission profile of WHO-12 PCBs. Results showed that WHO-12 PCBs were formed in the same regions of the sinter strand as 2,3,7,8-PCDD/Fs, indicating that there was a strong correlation between the formation of WHO-12 PCBs and PCDD/Fs in the iron ore sintering process.