The BIOZO process--a biofilm system combined with ozonation: occurrence of xenobiotic organic micro-pollutants in and removal of polycyclic aromatic hydrocarbons and nitrogen from landfill leachate.

We present an assessment of xenobiotic organic micro-pollutants (XOM) occurrence and removal of polycyclic aromatic hydrocarbons (PAHs) in a novel biofilm system combined with ozonation, the BIOZO concept, treating partly stabilised landfill leachate. A novel, staged moving-bed biofilm reactor (SMBBR) design was implemented in laboratory- and pilot-scale, and the PAHs removal efficiency of controlled ozonation was assessed installing the ozonation step in the nitrate recirculation line (Position 1) or between the pre-anoxic and aerobic zones (Position 2). COD removal in a laboratory- and in a pilot-scale SMBBR system with and without ozonation is additionally addressed. Results obtained in a screening study (GC-ToF-MS) were used to compile a priority list of XOMs in leachate based on relative occurrence, showing PAHs as the predominant fraction. Biological treatment is shown to be an effective means to remove PAHs detected in the aqueous phase. PAH removal takes in most part place in the pre-anoxic zone, thereby decreasing toxicity exhibited by PAH on autotrophic nitrifier bacteria in the aerobic zone. Ozonation installed in Position 2 is shown to be superior over Position I in terms of COD, PAH and nitrogen removal efficiencies. We additionally demonstrate the potential of intermittent sludge ozonation as a means to decrease PAH concentrations in sludge wasted and to improve nitrogen removal in the BIOZO system.

Diabetes and the risk of lung cancer.

OBJECTIVE: The incidence of some cancers has been reported to be higher in diabetic patients than in the general population. We estimated the incidence of lung cancer in diabetic patients and investigated the hypothesis that the rate of lung cancer is different in diabetic compared with nondiabetic patients. RESEARCH DESIGN AND METHODS: Diabetic patients and age-, sex-, and general practice-matched nondiabetic control subjects were identified from U.K. computerized general practice records (General Practice Research Database), and these records searched for any incident lung cancer, demographic details, and smoking status. Primary lung cancer incidence was calculated and rates compared between diabetic patients and nondiabetic control subjects using multivariate Cox regression, adjusting for age, sex, and smoking. The comparison was repeated for incident diabetic patients followed from diagnosis and after stratifying by diabetic treatment. RESULTS: The incidence of primary lung cancer in all 66,848 diabetic patients was 1.63 per 1,000 patient-years (95% CI 1.48-1.79) and 2.05 per 1,000 patient-years (1.76-2.38) among diabetic patients followed from diagnosis. When compared with nondiabetic control subjects, the hazard ratio was 0.88 (0.79-0.97) for all diabetic patients and 1.12 (0.95-1.34) for those followed from diagnosis. When observation was truncated to allow for shorter life expectancy, the hazard ratio for the total cohort was 0.98 (0.84-1.13), and no association was found with any treatment group. CONCLUSIONS: No increased risk of lung cancer in diabetes was found. We hypothesize that the lower incidence may be partly due to shorter life expectancy.

Effects of simulated weathering on the toxicity of selected crude oils and their components to sea urchin embryos.

Artificial weathering of Angolan crude and a Heavy Fuel Oil (HFO) was performed by evaporation and photooxidation. The aliphatic, aromatic, polar and asphaltene fractions of the fresh and weathered oils were isolated. The toxicity of the water accommodated fraction or an oil/fraction dissolved in DMSO was assessed using the sea urchin embryo test. Photooxidation was observed to decrease the aromatics content and increase polar compounds. A slight reduction in the toxicity of Angolan crude was observed following weathering for the water-accommodated fraction and the extract in DMSO, but no effect was seen for the Heavy Fuel Oil. For aliphatic compounds, the toxicity decreased in the order fresh>evaporated>photooxidated for both Angolan crude and HFO. Weathering slightly increased the toxicity of the aromatic and polar fractions of the oil. The aromatic fractions were responsible for most of the toxicity and the polar compounds were the second most important toxic components, despite having less or similar abundance than the aliphatic fraction. The toxic contribution of the aromatic compounds was higher for the HFO than for the Angolan crude. A decrease in the toxicity of Angolan crude following weathering correlated with a reduction in the toxicity of the aliphatic fraction.

Measuring nonpolar organic contaminant partitioning in three Norwegian sediments using polyethylene passive samplers.

Freely dissolved pore water concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), penta- and hexachlorobenzene (PeCB and HCB), octachlorostyrene (OCS), p,p'-DDE and p,p'-DDD were measured in bottom sediments from three sites in Norway. Sediments were from Aker Brygge, site of a former shipyard in the inner part of Oslofjord, Frierfjord in the Grenlandsfjord area, impacted during the 50 year-long activity of a magnesium smelter plant, and from Kristiansand harbour, site with high industrial activity. Low density polyethylene (LDPE) membrane samplers were exposed to these sediments in laboratory incubation under constant and low-level agitation for periods of 1, 2, 6, 13, 23 and 50 days. Freely dissolved pore water concentrations were estimated from contaminant masses accumulated and sampling rates obtained from the measurement of kinetics of dissipation of performance reference compounds (PRCs). Marked differences in freely dissolved PAH concentrations and resulting organic carbon-normalised sediment-pore water partition coefficients, logK(TOC), between these three sediments could be observed despite the generally similar total sediment concentrations. In contrast with the PAH data, partitioning of PCBs and other organochlorine compounds (OCs) was relatively similar in all three sediments. For sediments from Frierfjord and Kristiansand, logK(TOC) values were lower for PCBs/OCs than for PAHs, indicating higher availability. Similar partitioning of PAHs and PCBs/OCs was found for sediments from Aker Brygge. No simple logK(oc)-logK(ow) relationships could model these data successfully. These results support the notion that the assessment of the risk posed by these compounds present in sediments in most cases requires actual measurement of contaminant availability.

Myocardial infarction and third generation oral contraceptives: aggregation of recent studies.

BACKGROUND: Arterial cardiovascular and cerebrovascular adverse events associated with oral contraceptives (OC) are a major concern to the clinician. This paper aggregates the findings of seven recent oral contraceptive studies on the risk of acute myocardial infarction (MI) among users of second (2gen) and third (3gen) generation OC. METHODS: Odds ratios (OR) from seven original studies published between 1996 and 2001 underwent meta-analysis. They had accrued 6464 subjects since 1996. In addition, estimates of 22 studies published from 1965 to 1966 were synthesized using medians and ranges as an historical point of reference. RESULTS: Four meta-analyses were performed for each of the relevant comparisons. The point estimates for 3gen versus 2gen OC ranged from 0.44 (0.24-0.80) to 0.62 (0.38-0.99). Compared with non-users, the aggregated OR for 3gen OC was 1.13 (0.66-1.92); for 2gen OC it was 2.18 (1.62-2.94). CONCLUSIONS: This overview of seven controlled observational studies confirms that 3gen OC do not convey harm in regard to MI compared with non-users of OC. The aggregate data and the continuing replication of findings allow interpretation of benefit compared with older combined OC.

Triptans in migraine: the risks of stroke, cardiovascular disease, and death in practice.

BACKGROUND: Triptans are widely used to treat migraine but have been associated with stroke, myocardial infarction (MI), and ischemic heart disease (IHD) in case reports. OBJECTIVE: To estimate the incidence of stroke, cardiovascular events, and death in a migraine cohort, stratified by triptan prescription, and investigate whether the risk of these events was increased in those treated with triptans. METHODS: Migraine patients and matched nonmigraine control subjects were identified from the General Practice Research Database. Computerized records were searched for triptan prescriptions, stroke, TIA, MI, IHD, death, arrhythmia, and confounding variables. Incidence rates were calculated and migraine groups compared with controls using a Cox model, adjusting for confounders. RESULTS: Of 63,575 migraine patients, 13,664 were prescribed a triptan. There was no association between triptan prescription and stroke (hazard ratio [HR] 1.13; 95% CI 0.78, 1.65), MI (HR 0.93; 95% CI 0.60, 1.43), or other outcomes studied. The larger group of migraine patients not prescribed a triptan had an increased risk of stroke (HR 1.51; 95% CI 1.26, 1.82) and IHD (HR 1.35; 95% CI 1.18, 1.54) and a decreased risk of all-cause mortality (HR 0.72; 95% CI 0.65, 0.80). CONCLUSIONS: In general practice, triptan treatment in migraine does not increase the risk of stroke, MI, cardiovascular death, IHD, or mortality. Triptans are prescribed to those less at risk of these events.