Repeated dose inhalation developmental toxicity study in rats exposed to cellulose insulation with boric acid additive.

Cellulose insulation (CI), a common building material, is a mixture of cellulose fibers and borates. Borates are approximately 20% of the product weight and act as a flame retardant. Given possible exposure to workers and consumers, an inhalation toxicity study was conducted following Organization for Economic Co-operation and Development (OECD) 414 for Prenatal Development Toxicity to evaluate if CI is a developmental toxicant. Pregnant female rats were exposed by nose-only inhalation to CI aerosols containing 20% boric acid for six h/day, from gestational day (GD) 6-19, and fetuses were evaluated for developmental parameters. Respirable CI was produced by grinding to produce respirable particles (MMAD 2.7-2.9 µm, geometric standard deviations (GSD) 1.9-2.6), which were then aerosolized. Target air concentrations were 15, 90, and 270 mg CI/m3. Controls were exposed to air only. Slight body weight reductions (average decrease <7% vs. control) were observed in male and female GD 20 fetuses in the mid and high dose groups. No embryo/fetal developmental toxicity or alterations in any other measured variable were reported at any dose. The no observed adverse effect level (NOAEL) for developmental outcomes was 270 mg/m3.

The Cancer Risk Associated with Residential Exposure to Soil Containing Radioactive Coal Combustion Residuals.

Coal combustion residuals (CCRs) are composed of various constituents, including radioactive materials. The objective of this study was to utilize methodology on radionuclide risk assessment from the Environmental Protection Agency (EPA) to estimate the potential cancer risks associated with residential exposure to CCR-containing soil. We evaluated potential radionuclide exposure via soil ingestion, inhalation of soil particulates, and external exposure to ionizing radiation using published CCR radioactivity values for 232 Th, 228 Ra, 238 U, and 226 Ra from the Appalachia, Illinois, and Powder River coal basins. Mean and upper-bound cancer risks were estimated individually for each radionuclide, exposure pathway, and coal basin. For each radionuclide at each coal basin, external exposure to ionizing radiation contributed the greatest to the overall risk estimate, followed by incidental ingestion of soil and inhalation of soil particulates. The mean cancer risks by route of exposure were 2.01 × 10-6 (ingestion), 6.80 × 10-9 (inhalation), and 3.66 × 10-5 (external), while the upper bound cancer risks were 3.70 × 10-6 (ingestion), 1.18 × 10-8 (inhalation), and 6.15 × 10-5 (external), using summed radionuclide-specific data from all locations. The upper bound cancer risk from all routes of exposure was 6.52 × 10-5 . These estimated cancer risks were within the EPA's acceptable cancer risk range of 1 × 10-6 to 1 × 10-4 . If the CCR radioactivity values used in this analysis are generally representative of CCR waste streams, then our findings suggest that CCRs would not be expected to pose a significant radiological risk to residents living in areas where contact with CCR-containing soils might occur.

No evidence available on best therapies for postextraction haemorrhage.

Data sourcesThe review searched for published and ongoing trials in several databases with no restrictions on language or date of publication which included the Cochrane Oral Health Group Trials, Central Register of Controlled Trials, Medline, CINAHL, Embase, WHO Clinical Trials Registry Platform and clinical trial.gov.Study selectionRandomised clinical trials were considered that evaluated any intervention compared with another or with placebo for treating postoperative bleeding (PEB), post extraction. The primary outcome measures sought were: bleeding, amount of blood loss and cessation time required to control bleeding. The secondary outcomes: patient reported outcomes, such as pain or discomfort and adverse events.Data extraction and synthesisThree pairs of review authors independently screened the records.ResultsThe search strategy identified 1526 articles and abstracts. After removal of duplicates, 943 records were screened. Thirty-four full texts were examined. No trials met the inclusion criteria for the review.ConclusionsWe were unable to identify any reports of randomised controlled trials that evaluated the effects of different interventions for the treatment of post-extraction bleeding. In view of the lack of reliable evidence on this topic, clinicians must use their clinical experience to determine the most appropriate means of treating this condition, depending on patient-related factors. There is a need for well designed and appropriately conducted clinical trials on this topic, which conform to the CONSORT statement (www.consort-statement.org/).

No evidence that bonding is needed for amalgam restorations.

Data sourcesRelevant databases were searched for the review such as the Cochrane Oral Health Group Trials Register, Medline, EMBASE, clinical trials.gov, WHO International Clinical Trials Registry Platform.Study selectionRandomised controlled trials comparing adhesively bonded versus non-bonded class I and II amalgam restorations in permanent molars and premolars.Data extraction and synthesisTwo reviewers independently screened papers and extracted data.ResultsOne trial with 31 patients who received 113 restorations was included. At two years, 50 out of 53 restorations in the non-bonded group survived and 55 of 60 restorations survived with five unaccounted for at follow-up. Post insertion sensitivity was not statistically significant at baseline and for the two-year follow-up. No fractures or differences in the marginal adaptation were reported.ConclusionsThere is no evidence either to claim or to refute a difference in survival between bonded and non-bonded amalgam restorations. In view of the lack of evidence on the additional benefit of adhesively bonding amalgam in comparison with non-bonded amalgam, it is important that clinicians be mindful of the additional costs that may be incurred.

Implant outcomes poorer in patients with history of periodontal disease.

Data sourcesMedline and Embase databases and bibliographies of all included articles and relevant review articles were screened for possible inclusion.Study selectionLongitudinal studies were included reporting on implant survival, success, incidence of peri-implantitis, bone loss and periodontal status and on partially dentate patients with a history of treatment for periodontitis. There were no language restrictions for the included studies.Data extraction and synthesisAuthors independently and in duplicate assessed the studies for eligibility and data extraction. Disagreements were resolved by discussion and consensus. The methodological quality assessment of the included studies was done using an adapted Newcastle-Ottawa Scale (NOS). Confounding factors such as smoking, systemic disease influencing osseointegration, chemotherapy and radiation were assessed and adjusted in the analysis. Data were organised into tables and grouped in accordance with the study design.ResultsTwenty-four studies reported in 27 publications were included. Implant survival and success rate were higher in periodontally healthy patients.Twelve prospective cohort studies, five case series with a control group, four retrospective cohort studies and three studies with a sub group comparison were included.Bone loss and peri-implantitis were increased in patients with a history of treated periodontitis. More complications were reported in patients presenting with more severe forms of periodontitis. High heterogeneity among the studies in terms of study design, population, therapy, unit of analysis, inconsistent definitions of baseline and outcomes, inadequate reporting and confounding factors meant a meta-analysis could not be performed.Most of the studies showed better implant survival rates for the non-periodontitis group ranging from 91.67% to 100% compared to the treated periodontitis group 79.22% to 100% over a 1.2 to 16 year follow-up.ConclusionsImplants placed in patients treated for periodontal disease are associated with higher incidence of biological complications and lower success and survival rates than those placed in periodontally healthy patients. Severe forms of periodontal disease are associated with higher rates of implant loss. The conclusion of the review is limited by the strength of the evidence.

To cord or not to cord? That is still a question.

Data sourcesA broad computerised search with similar key terms was performed in different databases that included: Ovid Medline, Thomson's ISI Web of Science, PubMed, Science Direct, EMBASE and the Cochrane Library. Grey literature, dissertations, abstracts and theses were searched too. Reference lists of the selected articles were hand-searched.Study selectionThe inclusion criteria included in vivo randomised clinical trials and quasi-randomised clinical trials using gingival retraction techniques with and without cord. Studies were included if they examined the primary outcome from the review: efficiency of haemostasis control, the amount of gingival displacement and the influence of the techniques on gingival/periodontal health. Secondary outcomes accepted for the review included subjective factors reported by the patient such as pain, sensitivity, unpleasant taste and discomfort and operator's experience with both techniques. Non-English papers, clinical reports, animals studies or in vitro studies were excluded.Data extraction and synthesisTwo authors independently searched and screened the articles. Disagreements were resolved by discussion. A third reviewer participated in the eligibility of the studies. The risk of bias was assessed using the Cochrane Collaboration tool. Due to the heterogeneity of measurement variables across the studies and the differences among the studies, a meta-analysis was not performed. A narrative assessment was performed for the outcomes: moisture/bleeding control, gingival displacement, gingival/periodontal health and the subjective outcomes.ResultsFrom the initial search that retrieved 1,342 articles, 19 potential relevant full-text articles were considered for the review. Seven studies were selected for the systematic review. Four randomised clinical trials were included. Sample size ranged from eight to 252 participants per study. Five studies were conducted on patients requiring any indirect fixed restorations on prepared teeth. Two studies were done on unprepared teeth. In all studies, participants were in good health, had a healthy gingival condition and a sound periodontal status.ConclusionsBoth techniques are reliable in achieving gingival retraction. The review supports the observation that gingival retraction paste can more effectively help to achieve a dry field and at the same time be less injurious to soft tissues, however its ability to displace gingival tissues, compared to retraction cord, was compromising. Rather than considering the cost of material or the individual preference of the operator, choosing the right technique to maximise clinical efficiency should be based on scientific evidence. It seems that impregnated gingival cords are more effective on thick gingival tissue whereas paste is more effective when minimal retraction is required for haemostasis control, preservation of the gingiva and less tissue displacement.

The impact of smoking on failure rates, postoperative infection and marginal bone loss of dental implants.

DATA SOURCES: Electronic searches were undertaken in PubMed/Medline, Web of Science, Cochrane Oral Health Group Trials Register as well as hand searching. STUDY SELECTION: Clinical human studies, either randomised or not, providing outcome data for dental implant failure in smokers and non-smokers in any group of patients with no follow-up restrictions. Patients smoking a minimum of one cigarette a day were classified as smokers and implant failure was considered as the complete loss of the implant.Data extraction and synthesisThree authors independently participated in the inclusion criteria and disagreements were resolved by discussion. Quality assessment of the studies was performed using a scale to appraise observational studies. From the selected studies, data were extracted when available which included year of publication, study design, country, setting, number of patients, type of smokers, age, follow-up, days of antibiotic prophylaxis, failure, postoperative infection, marginal bone loss, implant surface, dental arch receiving implants, type of prosthetic rehabilitation and opposing dentition. For the meta-analysis, implant failure and postoperative infection were evaluated as dichotomous outcomes, while weighted mean differences were used for marginal bone loss as a continuous outcome. The statistical unit was the implant. Heterogeneity was calculated using I(2) test. RESULTS: From 1432 records identified, 107 publications were included in the review for the qualitative and quantitative synthesis. One hundred and four studies compared implant failure rates. From the total studies, the authors judged 85 to be of high quality and 22 of moderate quality. The meta-analysis for failure rate resulted in a statistically significant overall result of risk ratio (RR) of 2.23 (95% CI 1.96-2.53) heterogeneity of I(2): 51%. The meta-analysis of four studies evaluating the risk of postoperative infections in smokers presented a statistically significant result with an RR: 2.01, 95% CI 1.09-3.72, heterogeneity I(2): 0%, and the marginal bone loss had an overall statistically significant difference of MD 0.32, 95% CI 0,21-043; heterogeneity in this case was I(2): 95%. CONCLUSIONS: The insertion of implants in smokers affected the failure rates, the risk of postoperative infections, as well as the marginal bone loss. The results should be interpreted with caution due to the presence of uncontrolled confounding factors in the included studies.

Accuracy of dental radiographs for caries detection.

Data sourcesMedline, Embase, Cochrane Central and grey literature, complemented by cross-referencing from bibliographies. Diagnostic reviews were searched using the Medion database.Study selectionStudies reporting on the accuracy (sensitivity/specificity) of radiographic detection of primary carious lesions under clinical (in vivo) or in vitro conditions were included. The outcome of interest was caries detection using radiographs. The study also assessed the effect of the histologic lesion stage and included articles to assess the differences between primary or permanent teeth, if there had been improvements recently due to technical advances or radiographic methods, or if there are variations within studies (between examiners or applied radiographic techniques).Data extraction and synthesisData extraction was done by one reviewer first, using a piloted electronic spreadsheet and repeated independently by a second reviewer. Consensus was achieved by discussion. Data extraction followed guidelines from the Cochrane Collaboration. Risk of bias was assessed using QUADAS-2. Pooled sensitivity, specificity and diagnostic odds ratios (DORs) were calculated using random effects meta-analysis. Analyses were performed separately for occlusal and proximal lesions. Dentine lesions and cavitated lesions were analysed separately.Results947 articles were identified with the searches and 442 were analysed full text. 117 studies (13,375 teeth, 19,108 surfaces) were included. All studies were published in English. 24 studies were in vivo and 93 studies were in vitro. Risk of bias was found to be low in 23 and high in 94 studies. The pooled sensitivity for detecting any kind of occlusal carious lesions was 0.35 (95% CI : 0.31/40) and 0.41 (0.39/0.44) in clinical and in vitro studies respectively while the pooled specificity was 0.78 (0.73/0.83) and 0.70 (0.76/0.84). For the detection of any kind of proximal lesion the sensitivity in the clinical studies was 0.24 (CI 0.21/0/26) and 0.43 (0.41/0.45) and the specificity was 0.97 (0.95/0.98) and 0.89 (0.88/0.90).With regard to the dentine lesions the sensitivities were 0.36 (0.24-0.49) for proximal to 0.56 (0.53-0.59) for occlusal lesions and specificities ranged between 0.87 (0.85-0.89) and 0.95 (0.94-0.96). No reports were found for cavitated occlusal lesions. For proximal lesions sensitivities were above 0.60 and sensitivities above 0.90. Diagnostic Odds Ratios (DOR) were >1 (indicates a useful test) and were higher in proximal than in occlusal lesions. The DOR calculated for proximal lesions in vitro studies was 16.0 (11.5/22.4) and DOR 7.5 (3.4/16.5) for clinical studies). Heterogeneity calculated using I(2) test was moderate: > 50-67%.ConclusionsCaries detection determined by dental radiographs is highly accurate for proximal lesions and dentine caries lesions. For initial carious lesions the test needs to be used with other more sensitive methods in populations that present with high caries risk.

Unclear results for the use of botulinum toxin therapy for TMD pain.

DATA SOURCES: A comprehensive search was carried out on major databases such as PubMed, EMBASE and Cochrane CENTRAL. Reference lists of the included studies were explored along with journals likely to contain studies relevant to the topic. The search was restricted to the English language. STUDY SELECTION: The inclusion criteria included randomised and quasi-randomised controlled trials including parallel or cross-over studies comparing botulinum toxin therapy (BTX) versus any alternative intervention or placebo. DATA EXTRACTION AND SYNTHESIS: Quality assessment and data extraction were done following the Cochrane risk of bias tool and recommendations. All of the steps in the review, including the search and selection process, were done independently by two reviewers. Disagreements were discussed with one another until consensus was reached. RESULTS: Five relevant studies were included in the review, which consisted of 117 participants. Two trials revealed a significant inter-group difference in myofascial pain reduction. Another trial that compared BTX with fascial manipulation showed no significant difference in pain relief for temporomandibular disorders (TMDs), while the remaining two trials showed no significant difference between the BTX and placebo groups. Meta-analysis was not performed due to the considerable variation in study methods and evaluation of the results. All five studies were targeted primarily on the masseter and temporalis muscles and most of them administered injections at bilateral muscle sites. The methods used to find the muscles to target were all based on physical examination, with three studies using electromyography (EMG) as guidance. The dose of BTX ranged from 70U to 300U, the majority used being 100-150U. All studies gave a single session of BTX and re-evaluated participants at least one month following the injection. CONCLUSIONS: No consensus could be reached on the therapeutic benefit of BTX on TMDs.

Antibiotic use at dental implant placement.

DATA SOURCES: Cochrane Oral Health Groups Trial Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE via OVID and EMBASE via OVID. Databases were searched with no language or date restrictions. STUDY SELECTION: Two authors independently reviewed the titles and the abstracts for inclusion. Disagreements were resolved by discussion. If needed, a third author was consulted. Included were randomised clinical trials with a follow-up of at least three months which evaluated the use of prophylactic antibiotic compared to no antibiotic or a placebo and examined different antibiotics of different doses and durations in patients undergoing dental implant placement. The outcomes were implant failure (considered as implant mobility, removal of implant due to bone loss or infection) and prosthesis failure (prosthesis could not be placed). DATA EXTRACTION AND SYNTHESIS: Standard Cochrane methodology procedures were followed. Risk of bias was completed independently and in duplicate by two review authors. Results were expressed as risk ratios (RRs) using a random-effects model for dichotomous outcomes with 95% confidence intervals (CI). The statistical unit was the participant and not the prosthesis or implant. Heterogeneity including both clinical and methodological factors was investigated. RESULTS: Six randomised clinical trials with 1162 participants were identified for the review. Three trials compared 2 g of preoperative amoxicillin versus placebo (927 participants). One trial compared 3 g of preoperative amoxicillin versus placebo (55 participants). Another trial compared 1 g of preoperative amoxicillin plus 500 mg four times a day for two days versus no antibiotic (80 participants). An additional trial compared four groups: (1) 2 g of preoperative amoxicillin; (2) 2 g of preoperative amoxicillin plus 1 g twice a day for seven days; (3) 1 g of postoperative amoxicillin twice a day for seven days and (4) no antibiotics (100 participants). The overall body of the evidence was considered moderate.The meta-analysis of the six trials showed a statistically significant higher number of implant failures in the group not receiving antibiotics, RR= 0.33 (95% CI; 0.16 to 0.67) P = 0.0002.The number needed to treat for one additional benefit outcome (NNTB) to prevent one person having an implant failure is 25 (95% CI; 14 to 100) based on an implant failure of 6% in participants not receiving antibiotics.There was borderline statistical significance for prosthesis failures (RR= 0.44 (95%CI; 0.19 to 1.00) with no statistically significant differences for infections or adverse events. No conclusive information for the different durations of antibiotics could be determined. CONCLUSIONS: There is statistically significant evidence suggesting that a single dose of 2 g or 3 g of amoxicillin given orally is beneficial in reducing dental implant failure in ordinary conditions. No significant adverse events were reported. It is still unknown whether post-operative antibiotics are beneficial and which antibiotic is more effective.

Antibiotic prophylaxis for dental implant placement?

DATA SOURCES: Electronic searches without time or language restrictions were performed in PubMed, Web of Science and the Cochrane Oral Health Group trials Register. A vast manual search was done in many dental implant-related journals. Reference lists were scanned for possible additional studies. Ongoing clinical trials were also searched. STUDY SELECTION: Titles and abstracts of the reports identified were read independently by the three authors. Disagreements were resolved by discussion. Rejected studies were recorded with the reasons for exclusion. The inclusion criteria included clinical human studies, either randomised or not, comparing the implant failure/survival rates in any group of patients receiving antibiotic prophylaxis versus not receiving antibiotics prior to implant placement. Case reports and non-human studies were excluded. Implant failure was considered as complete loss of the implant. DATA EXTRACTION AND SYNTHESIS: Data were extracted by the authors. Study risk of bias was assessed. Implant failure and post-operative infection were the outcomes measured, both dichotomous outcomes. Results were expressed using fixed or a random effect model depending on the heterogeneity calculated using an I(2) statistical test. The estimate of relative effect was expressed in risk ratio (RR) with 95% confidence interval. Number needed to treat (NNT) was calculated and sensitivity analysis was performed to detect differences among the studies considered to have high a risk of bias. RESULTS: Fourteen trials were included in the review and evaluated a total of 14,872 implants. Of the fourteen studies included in the review eight were randomised clinical trials, four were controlled clinical trials and two were retrospective studies. Seven studies had both patients and operators/outcome assessors blinded to the tested intervention. Nine studies had short follow-ups; six of them with a follow-up of four months, one of five months and two of six months.The antibiotic regimen was variable: seven studies did not use post-op antibiotics in all patients. Seven studies used amoxicillin as the antibiotic of choice. Ten studies had patients rinse with antimicrobial solutions as well.Among the fourteen studies, 8603 implants were placed in patients receiving antibiotics, 304 failures (3.53%) were recorded; 6269 implants were placed in patients not receiving antibiotics or receiving placebo, with 396 failures recorded (6.32%).From eight articles that provided the information about post-operative infection there were 25 occurrences of infection in 1000 patients receiving antibiotics (2.5%) and 29 episodes in 770 patients not receiving antibiotics (3.8%).Some studies involved grafting procedures and a portion of the patients (in nine studies) were smokers.The test of overall effect for implant failure rate showed that the difference between the procedures with or without antibiotic is statistically significant: RR 0.55, 95% confidence interval (CI) 0.41 to 0.75, p value 0.0002, a relative risk reduction (RRR) of 45% and the number needed to treat (NNT) of 50 (95% CI 33-100).For the post operative infection outcome, the results of the meta-analysis showed no statistically significant results; RR 0.84, 95 % confidence interval 0.49-1.44, and a p value of 0.52.The results did not differ in the sensitivity analysis when removing the high risk of bias studies. For the implant failure, the results were RR 0.37, 95% CI 0.19-0.72, p value 0.003, and for the 'post operative infection' outcome the results were RR 0.78, 95% CI 0.38-1.39. p value 0.33. The funnel plot to calculate publication bias showed asymmetry for the studies reporting implant failure, while the studies reporting post-operative infection the funnel plot did not show asymmetry. CONCLUSIONS: The evidence from the review suggests that a prophylactic antibiotic regimen reduces failure of dental implants placed under ordinary conditions. However, there are no apparent differences in the occurrence of post-operative infections in patients receiving or not receiving antibiotics.The results have to be interpreted with caution due to the presence of several cofounding factors in the studies.

Trials needed to identify best management of iatrogenic inferior alveolar and lingual nerve injuries.

DATA SOURCES: The Cochrane Oral Health Group's Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), Medline and Embase databases were searched with no language or date restrictions. STUDY SELECTION: Three reviewers independently selected studies. Randomised controlled trials (RCTs) involving interventions to treat patients with neurosensory defect of the inferior alveolar or lingual nerve or both as a sequela of iatrogenic injury were considered. DATA EXTRACTION AND SYNTHESIS: Standard Cochrane methodological procedures were followed. RESULTS: Two studies considered at high risk of bias, reporting data from 26 analysed patients were included. Both studies investigated the effectiveness of low-level laser treatment compared to placebo laser therapy on inferior alveolar sensory deficit as a result of iatrogenic injury. Two studies assessed as at high risk of bias, reporting data from 26 analysed participants were included in this review. The age range of participants was from 17 to 55 years. Both trials investigated the effectiveness of low-level laser treatment compared to placebo laser therapy on inferior alveolar sensory deficit as a result of iatrogenic injury.Patient-reported altered sensation was partially reported in one study and fully reported in another. Following treatment with laser therapy, there was some evidence of an improvement in the subjective assessment of neurosensory deficit in the lip and chin areas compared to placebo, though the estimates were imprecise: a difference in mean change in neurosensory deficit of the chin of 8.40 cm (95% confidence interval (CI) 3.67 to 13.13) and a difference in mean change in neurosensory deficit of the lip of 21.79 cm (95% CI 5.29 to 38.29). The overall quality of the evidence for this outcome was very low. No studies reported on the effects of the intervention on the remaining primary outcomes of pain, difficulty eating, speaking or taste. No studies reported on quality of life or adverse events. CONCLUSIONS: There is clearly a need for randomised controlled clinical trials to investigate the effectiveness of surgical, medical and psychological interventions for iatrogenic inferior alveolar and lingual nerve injuries. Primary outcomes of this research should include: patient-focused morbidity measures including altered sensation and pain, pain, quantitative sensory testing and the effects of delayed treatment.

The effect of clothing care activities on textile formaldehyde content.

Textiles are commonly treated with formaldehyde-based residues that may potentially induce allergic contact dermatitis in sensitive individuals. This study examined the initial formaldehyde content in clothing and resulting changes due to care activities. Twenty clothing articles were examined and 17 of them did not have detectable levels of formaldehyde. One shirt contained a formaldehyde concentration of 3172 ppm, and two pairs of pants had formaldehyde concentrations of 1391 ppm and 86 ppm. The two highest results represent formaldehyde levels that are up to 40-fold greater than international textile regulations. The two items with the greatest formaldehyde content were washed and dried in a manner similar to that used by consumers, including hand and machine washing in hot or cold water followed by air or machine drying. The washing and drying procedures reduced formaldehyde levels to between 26 and 72% of untreated controls. Differences in the temperature or type of washing and drying did not result in a clear trend in the subsequent formaldehyde content. In addition, samples were hot ironed, which did not affect the formaldehyde content as significantly. Understanding the formaldehyde content in clothing and its potential reduction through care activities may be useful for manufacturers and formaldehyde-sensitive individuals.

An analysis of historical exposures of pressmen to airborne benzene (1938-2006).

Benzene is an aromatic hydrocarbon that, with sufficient cumulative lifetime doses, can cause acute myelogenous leukemia. Because of its volatility and solvent properties, it was used in the printing industry in inks, ink solvents, and cleaning agents from the 1930s to the 1970s. This analysis represents the first known attempt to gather and synthesize the available data on historical airborne benzene concentrations in printing facilities and exposures to pressmen. The sources of fugitive benzene vapors from printing operations have been identified as evaporation from ink fountains, exposed sections of the printing cylinder, the paper web, the paper post exit, and spilled ink. In addition, specific activities that could lead to benzene exposure, such as filling the fountains, using solvents to clean the press, and using solvents as personal cleaning agents, potentially occurred multiple times per work period. Eighteen studies were identified that reported workplace airborne concentrations in printing facilities between 1938 and 2006. Typical benzene air concentrations, considering both personal and area samples of various durations, were as high as 200 p.p.m. in the 1930s through the 1950s, 3-35 p.p.m. in the 1960s, 1.3-16 p.p.m. in the 1970s, 0.013-1 in the 1980s, and far less than 1 p.p.m. in the 1990s and 2000s. The decrease in benzene air concentrations by the late 1970s was likely to be linked to the decreased benzene content of printing materials, increased engineering controls, and to more stringent occupational exposure limits.

Microbubble drug conjugate and focused ultrasound blood brain barrier delivery of AAV-2 SIRT-3.

BACKGROUND: Delivery of viral vectors as gene therapies to treat neurodegenerative diseases has been hampered by the inability to penetrate the blood brain barrier (BBB) and invasive or non-targeted delivery options prone to inducing immune responses. MR guided focused ultrasound (MR-g-FUS) and microbubbles have demonstrated safe, temporary, targeted BBB permeabilization clinically. METHODS: We developed clinically scalable, microbubble drug conjugates (MDCs) for the viral gene therapy, AAV.SIRT3-myc [adeno-associated virus expressing myc-tagged SIRT3], which has previously been shown to have disease modifying effects in animal models of Parkinson's disease (PD). The lipid shells of the perfluorocarbon gas MDCs were covalently conjugated to antibodies with binding specificity to AAVs. Following systemic (iv) delivery of AAV.SIRT3-myc MDCs, MR-g-FUS was used to deliver SIRT3-myc to brain regions affected in PD. SIRT3-myc expression was determined post mortem, using immunohistochemistry. RESULTS: An in vitro, SH-SY5Y cell culture model was used to show that the localized destruction of MDCs using ultrasound exposures within biological safety limits dissociated AAV2-GFP (green fluorescent protein) from the MDCs in the targeted area while maintaining their transduction capacity. In rats, MR-g-FUS resulted in BBB permeabilization in the striatum and substantia nigra (SNc). SIRT3-myc was expressed in the striatum, but not the SNc. CONCLUSION: These studies demonstrate that MDCs combined with MR-g-FUS are an effective method for delivery of viral vector gene therapies, such as AAV.SIRT3, to brain regions affected in PD. This technology may prove useful as a disease-modifying strategy in PD and other neurodegenerative disorders.

Analysis and modeling of airborne BTEX concentrations from the Deepwater Horizon oil spill.

Concerns have been raised about whether the Deepwater Horizon oil spill cleanup workers experienced adverse health effects from exposure to airborne benzene, toluene, ethylbenzene, and xylene (BTEX) which volatilized from surfaced oil. Thus, we analyzed the nearly 20 000 BTEX measurements of breathing zone air samples of offshore cleanup workers taken during the six months following the incident (made publicly available by British Petroleum). The measurements indicate that 99% of the measurements taken prior to capping the well were 32-, 510-, 360-, and 77-fold lower than the U.S. Occupational Safety and Health Administration's Permissible Exposure Limits (PELs) for BTEX, respectively. BTEX measurements did not decrease appreciably during the three months after the well was capped. Moreover, the magnitudes of these data were similar to measurements from ships not involved in oil slick remediation, suggesting that the BTEX measurements were primarily due to engine exhaust rather than the oil slick. To supplement the data analysis, two modeling approaches were employed to estimate airborne BTEX concentrations under a variety of conditions (e.g., oil slick thickness, wind velocity). The modeling results corroborated that BTEX concentrations from the oil were well below PELs and that the oil was not the primary contributor to the measured BTEX.

COVID-19 and Health Disparities: Structural Evil Unmasked.

Background: Incidence and mortality from COVID-19 are starkly elevated in poor, minority and marginalized communities. These differences reflect longstanding disparities in income, housing, air quality, preexisting health status, legal protections, and access to health care. The COVID-19 pandemic and its economic consequences have made these ancient disparities plainly visible. Methodology: As scholars in Catholic research universities committed to advancing both scientific knowledge and social justice, we examined these disparities through the lenses of both epidemiology and ethics. Findings: We see these widening disparities as not only as threats to human health, societal stability, and planetary health, but also as moral wrongs - outward manifestations of unrecognized privilege and greed. They are the concrete consequences of policies that promote structural violence and institutionalize racism. Recommendations: We encourage governments to take the following three scientific and ethical justified actions to reduce disparities, prevent future pandemics, and advance the common good: (1) Invest in public health systems; (2) Reduce economic inequities by making health care affordable to all; providing education, including early education, to all children; strengthening environmental and occupational safeguards; and creating more just tax structures; and (3) Preserve our Common Home, the small blue planet on which we all live.

Deposition and spatial distribution of insecticides following fogger, perimeter sprays, spot sprays, and crack-and-crevice applications for treatment and control of indoor pests.

The indoor surface deposition and distribution of insecticides applied as foggers, baseboard or perimeter sprays, spot sprays and crack-and-crevice sprays represent distinct pathways of potential unintentional and unavoidable residential pesticide exposure of children and adults. Fogger, perimeter spray, crack-and-crevice, and spot sprays using registered commercial products were studied using three 5-part deposition plates positioned in unoccupied residences in Riverside, CA. Pesticide active ingredients included permethrin, chlorpyrifos, cyfluthrin, cypermethrin, and deltamethrin. Horizontal distribution factors of 100% (total release fogger in a small room), 50% (perimeter spray), 15% (crack-and-crevice), and 2% (spot spray) were assigned based upon application of selected commercial products by a licensed pest control operator and investigators who participated in these studies. This research reduces uncertainties associated with assessing human exposure following different application methods.

Lead testing wipes contain measurable background levels of lead.

Lead is registered under the California Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65) as both a carcinogen and a reproductive hazard. As part of the process to determine if consumer products satisfy Proposition 65 with respect to lead, various wipe sampling strategies have been utilized. Four commonly used wipe materials (cotton gauze, cotton balls, ashless filter paper, and Ghost Wipes) were tested for background lead levels. Ghost Wipe material was found to have 0.43 +/- 0.11 microg lead/sample (0.14 microg/wipe). Wipe testing for lead using Ghost Wipes may therefore result in measurable concentrations of lead, regardless of whether or not the consumer product actually contains leachable lead.