Formaldehyde exposure and its effects during pregnancy: Recommendations for laboratory attendance based on available data

Pregnancy, obstetrical and neonatal outcomes in women exposed to physician-related occupational hazards: a scoping review

OBJECTIVE

Evidence is needed to guide organisational decision making about workplace accommodations for pregnant physicians. Our objective was to characterise the strengths and limitations of current research examining the association between physician-related occupational hazards with pregnancy, obstetrical and neonatal outcomes.

DESIGN

Scoping review.

DATA SOURCES

MEDLINE/PubMed, EMBASE, CINAHL/ EBSCO, SciVerse Scopus and Web of Science/Knowledge were searched from inception to 2 April 2020. A grey literature search was performed on 5 April 2020. The references of all included articles were hand searched for additional citations.

ELIGIBILITY CRITERIA

English language citations that studied employed pregnant people and any 'physician-related occupational hazards', meaning any relevant physical, infectious, chemical or psychological hazard, were included. Outcomes included any pregnancy, obstetrical or neonatal complication.

DATA EXTRACTION AND SYNTHESIS

Physician-related occupational hazards included physician work, healthcare work, long work hours, 'demanding' work, disordered sleep, night shifts and exposure to radiation, chemotherapy, anaesthetic gases or infectious disease. Data were extracted independently in duplicate and reconciled through discussion.

RESULTS

Of the 316 included citations, 189 were original research studies. Most were retrospective, observational and included women in any occupation rather than healthcare workers. Methods for exposure and outcome ascertainment varied across studies and most studies had a high risk of bias in data ascertainment. Most exposures and outcomes were defined categorically and results from different studies could not be combined in a meta-analysis due to heterogeneity in how these categories were defined. Overall, some data suggested that healthcare workers may have an increased risk of miscarriage compared with other employed women. Long work hours may be associated with miscarriage and preterm birth.

CONCLUSIONS

There are important limitations in the current evidence examining physician-related occupational hazards and adverse pregnancy, obstetrical and neonatal outcomes. It is not clear how the medical workplace should be accommodated to improve outcomes for pregnant physicians. High-quality studies are needed and likely feasible.

Formaldehyde in Hospitals Induces Oxidative Stress: The Role of GSTT1 and GSTM1 Polymorphisms

Despite the toxicity and health risk characteristics of formaldehyde (FA), it is currently used as a cytological fixative and the definition of safe exposure levels is still a matter of debate. Our aim was to investigate the alterations in both oxidative and inflammatory status in a hospital working population. The 68 workers recruited wore a personal air-FA passive sampler, provided a urine sample to measure 15-F_2t-Isoprostane (15-F_2t-IsoP) and malondialdehyde (MDA) and a blood specimen to measure tumour necrosis factor α (TNFα). Subjects were also genotyped for GSTT1 (Presence/Absence), GSTM1 (Presence/Absence), CYP1A1 exon 7 (A > G), and IL6 (−174, G > C). Workers were ex post split into formalin-employers (57.3 μg/m³) and non-employers (13.5 μg/m³). In the formalin-employers group we assessed significantly higher levels of 15-F_2t-IsoP, MDA and TNFα (<0.001) in comparison to the non-employers group. The air-FA levels turned out to be positively correlated with 15-F_2t-IsoP (p = 0.027) and MDA (p < 0.001). In the formalin-employers group the MDA level was significantly higher in GSTT1 Null (p = 0.038), GSTM1 Null (p = 0.031), and CYP1A1 exon 7 mutation carrier (p = 0.008) workers, compared to the wild type subjects. This study confirms the role of FA in biomolecular profiles alterations, highlighting how low occupational exposure can also result in measurable biological outcomes.

The role of phase I, phase II, and DNA-repair gene polymorphisms in the damage induced by formaldehyde in pathologists

Formaldehyde (FA) is a human carcinogen used as formalin in hospital laboratories. We evaluated its association with human chromosomal aberrations (CAs) and the risk/protective role played by several genetic polymorphisms in this relationship, on a cohort of 57 exposed pathologists vs 48 controls. All subjects were assessed for CAs on peripheral blood lymphocytes and genotyped for the most common cancer-associated gene polymorphisms which could be related with the genotoxic outcome: CYP1A1 exon 7 (A>G), CYP1A1*2A (T>C), CYP2C19*2 (G>A), GSTT1 (Positive/Null), GSTM1 (Positive/null), GSTP1 (A>G), XRCC1 (G399A), XRCC1 (C194T), XRCC1 (A280G), XPD (A751C), XPC exon 15 (A939C), XPC exon 9 (C499T), TNFα - 308 (G>A), IL10 - 1082 (G>A), IL10 - 819 (C>T) and IL6 - 174 (G>C). Air-FA concentration was assessed through personal samplers. The comparison between pathologists and controls showed a significantly higher CAs frequency in pathologists. Significant positive correlations were found between CAs frequency and air-FA concentration while significant associations were found between variation in CAs frequency and the mutated allele for CYP1A1 exon 7 (A>G), CYP2C19*2 (G>A), GSTT1-positive, GSTM1-positive and XRCC1 (G399A). Our study confirms the role of FA as genotoxicity inductor, even in workers chronically exposed to low air-FA levels and reveals the role played by some genetic polymorphisms in this association, highlighting the importance of individual susceptibility biomarkers assessment in occupational health studies.

Coping with Tissue Sampling in Suboptimal Conditions: Comparison of Different Tissue Preservation Methods for Histological and Molecular Analysis

A high quality of samples is crucial for the success of the analysis and diagnostic purposes, and therefore the right method of conservation is vitally important for an optimal preservation of tissues. Indeed, the time to deliver the sample to the laboratory could be remarkably long, especially under suboptimal conditions, and the use of specific fixatives or cold storage may not be possible. Moreover, the portability and cost of storage equipment, their toxicity, and their ease of use play a central role when choosing the correct preservation method. The aim of this study was the identification of a reliable and economic method for tissue preservation, to be used in "in-field" sampling, suitable for both histological and molecular analysis. Punch biopsies were collected from six cattle livers. Comparisons among methods of preservation using RNAlater, silica beads, and under-vacuum was carried out. These methods were tested through considering different times and temperatures, assuming three days as a maximum time interval from sampling to laboratory and choosing 4 °C and 24 °C as references for refrigeration temperature and room temperature, respectively. Histologically, the integrity of nucleus, cytoplasm, preservation of liver structure, and easiness of recognition of inflammatory infiltrate were evaluated. The integrity of the extracted DNA and RNA was evaluated through PCR and by means of an automated electrophoresis station, respectively. RNAlater and silica beads poorly preserved the histological parameters evaluated, independently from the temperature. Conversely, the vacuum-sealed samples showed a good grade of preservation until 48 h. DNA quality was acceptable for each sample. RNA integrity showed promising results only for samples preserved with silica beads.

Occupational risk perceived by pregnant workers: proposal for an assessment tool for health professionals

Introduction

The risk factors and agents present in the work environment may represent a risk to the health of pregnant women, the developing infants, and breast-feeding mothers; however, tools to assess occupational exposure of these workers are not available.

Objective

To develop an instrument for the qualitative assessment of occupational exposure of pregnant workers based on their perceptions.

Method

We conducted a data survey from the National Institute for Occupational Safety and Health and the Brazilian Regulatory Standard 15. Next, a comparative analysis was performed, according to the scientific literature available, followed by a preliminary version of the instrument, a pilot test with 15 pregnant women, and preparation of the final version.

Results

A tool was developed consisting of 28 questions, divided into 7 categories: 1) pregnant or lactating woman; 2) habits and behaviors; 3) information about work; 4) risk factors identified by the worker in the work environment divided into chemical, physical, biological, ergonomic, and accidents; 5) difficulties faced at work; 6) need for antenatal leave; and 7) open question so that the worker can inform something she considers necessary.

Conclusions

The study of work-related risk factors and/or agents relevant to the health of pregnant women and/or the fetus is essential to conduct adequate prenatal care and to protect the health of these workers. The use of this tool can be of great value for health professionals, especially for physicians. The practical application can bring possible improvements that were not identified by the authors during the study.

Local exhaust ventilation systems for the gross anatomy laboratory

The inability to exhaust airborne formaldehyde and other volatile organic compounds from a gross anatomy laboratory is an impediment to gross anatomical education. Despite the importance of removing harmful airborne chemicals, there is scant information regarding how to build effective local exhaust ventilation systems. In this study, various exhaust systems were built and assessed for exhaust flow, airborne formaldehyde removal, and noise production with the aim of identifying inexpensive and simple exhaust systems that can create a healthy and quiet exhaust flow from a downdraft dissection table. The results of the study include details regarding 11 local exhaust ventilation systems, including an exhaust system that produces an exhaust flow of 777cfm, allows no detectable airborne formaldehyde (0ppm) despite a 1000mL pool of formalin (composed of 37% formaldehyde) positioned directly beneath a formaldehyde-meter, and operates at a very low noise level (maximum of 69.2dBA with coexisting baseline room noise of 38.6dBA). Furthermore, the aforementioned local exhaust ventilation system costs less than $400 (USD) to build and can be assembled in a matter of minutes with minimal know-how. The local ventilation systems assessed in this study were capable of down-drafting air away from the breathing zone; therefore, the utilization of such local ventilation systems may have the additional benefit of decreasing the person-to-person transmission of aerosolized pathogens. This information marks an improvement in laboratory health and safety measures, facilitates the creation of gross anatomy laboratories, and improves access to gross anatomical education.

Maternal occupational exposure to chemicals in the textile factory during pregnancy is associated with a higher risk of polydactyly in the offspring

Background: The number of children with polydactyly seen in our clinic is increasing. In addition to genetic factors, an influence of environmental effects during pregnancy is becoming increasingly apparent; however, epidemiological data on these effects are lacking.Methods: This hospital-based, case-control study enrolled 143 patients with polydactyly and 286 control patients with no genetic diseases, to evaluate the association between maternal exposure to a textile factory environment during pregnancy and the likelihood of giving birth to a child with polydactyly.Results: Maternal exposure to a textile factory environment during pregnancy was associated with an increased risk of giving birth to a child with polydactyly (exposure to textile factory environment: unadjusted odds ratio (OR) = 3.31, 95% confidence interval (CI) = 1.75-6.27, p = .0002; work seniority of exposed occupation: unadjusted OR 1.28, 95% CI = 1.13-1.47, p = .0002). Covariate screening indicated that certain risk factors (family monthly income per capita, mother's emotional state during pregnancy, colporrhagia, passive smoking, smoking, and history of consanguineous marriage) were potential confounding factors. After adjusting for these variables, the OR of exposure to a textile factory environment remained significant (exposure to textile factory environment: adjusted OR = 3.08, 95% CI = 1.32-7.19, p = .0094; work seniority of exposed occupation: adjusted OR = 1.58, 95% CI = 1.20-2.08, p = .0010). The risk of polydactyly increased with the number of years of employment.Conclusions: Maternal exposure to a textile factory environment appears to be a risk factor for polydactyly in newborns.

Challenges and implementation of the German maternity protection act for female medical students in macroscopic anatomical education

Background: Recent decades have seen controversial discussions on the validity of dissection courses in medical education, with alternative programs tested for various reasons. On April 1, 2015 the classification of formaldehyde as a hazardous substance was upgraded by the EU, leding to some universities precluding the participation of pregnant and breastfeeding students in dissection course. However, the revision to the Maternity Protection Act, implemented in Germany on January 1, 2018, now protects student mothers from being disadvantaged in their studies as a consequence of their pregnancy or breastfeeding. Therefore, universities must offer alternatives to dissection courses using formaldehyde to these female students. Project description: As an alternative to regular dissection courses, which use the abovementioned chemical, the Centre for Anatomy at Charité has opted for developing dedicated courses for student mothers. These new courses use plastinated prosection material instead of formalin-treated cadavers of body donors. As the core of the anatomical education takes place during the third and fourth semester in the current curriculum of human medicine at Charité the alternative courses are limited to those two semesters. Additionally, alternative exams at the end of both semesters had to be developed. The alternative courses were designed to offer pregnant and breastfeeding students a study program as close as possible to the one in which their peers learn human anatomy. Results: For the new courses, plastinates had to be produced and further specimens are still needed. Additionally required sets of bones, models and radiological images were readily available at the Centre for Anatomy. The planning and conceptualization of the courses took half a year of intense preparation. The courses for the third and fourth semester were first running during summer semester 2017. There is a clear demand for courses among pregnant and breastfeeding students. At least 5 student participants per course were registered, corresponding to every fortieth female student in their semester cohorts. The highest number of student participants was 13 in one course so far. The performances of the participants in the anatomical examinations were matching that of students attending the regular courses. Discussion: The alternative macroscopic anatomy courses enable the implementation of the revised Maternity Protection Act. The targeted student group is highly satisfied with the offered alternative courses. Considering the number of participants and their examination performance so far, the Centre for Anatomy regards the efforts involved in planning and implementing the courses as justified. The courses allow pregnant and breastfeeding students to address the same anatomical themes at the same time as their fellow students. However, due to restricted flexibility of plastinates and because students cannot prepare specific anatomical structures independently the scope of topographic learning is limited. That being said, well-produced plastinates can display anatomical structures which often cannot be dissected in regular courses. The alternative macroscopic anatomy courses using plastinates constitute suitable alternatives to the regular dissection courses with formalin-treated cadavers for pregnant and breastfeeding students.

Comparison of a Novel Cadaver Model (Fix for Life) With the Formalin-Fixed Cadaver and Manikin Model for Suitability and Realism in Airway Management Training

BACKGROUND

Manikins are widely used in airway management training; however, simulation of realism and interpatient variability remains a challenge. We investigated whether cadavers embalmed with the novel Fix for Life (F4L) embalmment method are a suitable and realistic model for teaching 3 basic airway skills: facemask ventilation, tracheal intubation, and laryngeal mask insertion compared to a manikin (SimMan 3G) and formalin-fixed cadavers.

METHODS

Thirty anesthesiologists and experienced residents ("operators") were instructed to perform the 3 airway techniques in 10 F4L, 10 formalin-fixed cadavers, and 1 manikin. The order of the model type was randomized per operator. Primary outcomes were the operators' ranking of each model type as a teaching model (total rank), ranking of the model types per technique, and an operator's average verbal rating score for suitability and realism of learning the technique on the model. Secondary outcomes were the percentages of successfully performed procedures per technique and per model (success rates in completing the respective airway maneuvers). For each of the airway techniques, the Friedman analysis of variance was used to compare the 3 models on mean operator ranking and mean verbal rating scores.

RESULTS

Twenty-seven of 30 operators (90%) performed all airway techniques on all of the available models, whereas 3 operators performed the majority but not all of the airway maneuvers on all models for logistical reasons. The total number of attempts for each technique was 30 on the manikin, 292 in the F4L, and 282 on the formalin-fixed cadavers. The operators' median total ranking of each model type as a teaching model was 1 for F4L, 2 for the manikin and, 3 for the formalin-fixed cadavers (P < .001). F4L was considered the best model for mask ventilation (P = .029) and had a higher mean verbal rating score for realism in laryngeal mask airway insertion (P = .043). The F4L and manikin did not differ significantly in other scores for suitability and realism. The formalin-fixed cadaver was ranked last and received lowest scores in all procedures (all P < .001). Success rates of the procedures were highest in the manikin.

CONCLUSIONS

F4L cadavers were ranked highest for mask ventilation and were considered the most realistic model for training laryngeal mask insertion. Formalin-fixed cadavers are inappropriate for airway management training.

Maternal Exposure to Indoor Air Pollution and Birth Outcomes

There is a growing body of research on the association between ambient air pollution and adverse birth outcomes. However, people in high income countries spend most of their time indoors. Pregnant women spend much of that time at home. The aim of this study was to investigate if indoor air pollutants were associated with poor birth outcomes. Pregnant women were recruited prior to 18 weeks gestation. They completed a housing questionnaire and household chemical use survey. Indoor pollutants, formaldehyde (HCHO), nitrogen dioxide (NO2) and volatile organic compounds (VOCs), were monitored in the women's homes at 34 weeks gestation. Gestational age (GA), birth weight (BW) and length (BL) and head circumference (HC) were collected from birth records. The associations between measured pollutants, and pollution surrogates, were analysed using general linear models, controlling for maternal age, parity, maternal health, and season of birth. Only HCHO was associated with any of the birth outcomes. There was a 0.044 decrease in BW z-score (p = 0.033) and 0.05 decrease in HC z-score (p = 0.06) for each unit increase in HCHO. Although HCHO concentrations were very low, this finding is consistent with other studies of formaldehyde and poor birth outcomes.

Changes in Work Practices for Safe Use of Formaldehyde in a University-Based Anatomy Teaching and Research Facility

Anatomy teaching and research relies on the use of formaldehyde (FA) as a preservation agent for human and animal tissues. Due to the recent classification of FA as a carcinogen, university hospitals are facing a challenge to (further) reduce exposure to FA. The aim of this study was to reduce exposure to FA in the anatomy teaching and research facility. Workers participated in the development of improved work practices, both technical and organizational solutions. Over a period of 6 years mitigating measures were introduced, including improvement of a down-flow ventilation system, introduction of local exhaust ventilation, collection of drain liquid from displayed specimens in closed containers and leak prevention. Furthermore, some organizational changes were made to reduce the number of FA peak exposures. Stationary and personal air sampling was performed in three different campaigns to assess the effect of these new work practices on inhalation exposure to FA. Samples were collected over 8 h (full shift) and 15 min (task-based) to support mitigation of exposure and improvement of work practices. Air was collected on an adsorbent coated with 2,4-dinitrophenylhydrazine (DNPH) and analyzed by HPLC-UV. Geometric mean (GM) concentrations of FA in the breathing zone over a work-shift were 123 µg/m³ in 2012 and 114 µg/m³ in 2014, exceeding the workplace standard of 150 µg/m³ (8 h time-weighted average, TWA) on 46% of the workdays in 2012 and 38% of the workdays in 2014. This exposure was reduced to an average of 28.8 µg/m³ in 2017 with an estimated probability of exceeding the OEL of 0.6%. Task-based measurements resulted in a mean peak exposures of 291 µg/m³ in 2012 (n = 19) and a mean of 272 µg/m³ in 2014 (n = 21), occasionally exceeding the standard of 500 µg/m³ (15 min TWA), and were reduced to a mean of 88.7 µg/m³ in 2017 (n = 12) with an estimated probability of exceeding the OEL of 1.6%.

Does oral spirulina protect the cornea from formaldehyde exposure? Application to anatomy laboratories

In this study, the protective effect of spirulina on corneal injury after formaldehyde (FA) exposure was assessed. Thirty adult male albino rats were divided into four groups. Group I: 12 rats were divided into two subgroups: I-a (negative control) and I-b (positive control). Group II (spirulina group): six rats received spirulina via an oral gavage feeding needle at a daily dose of 400 mg/kg b.w. Group III (FA exposure group): six rats were subjected to 10% FA inhalation for 2 h per day for 2 weeks (5 days per week). Group IV (FA exposure group treated with spirulina): six rats were exposed to 10% FA as in group III, with co-administration of spirulina as in group II. After 2 weeks, all the rats were sacrificed; the corneas were dissected and processed for paraffin sections. The sections were stained with hematoxylin and eosin (H&E), Masson's trichrome (MTC), or avidin-biotin peroxidase, and examined by light microscopy. The sections of rat cornea exposed to FA (Group III) showed disorganized and compressed epithelium with erosions. Subepithelial mononuclear cell infiltration and invasion of blood vessels were also evident. Stromal collagen fibers were disorganized and widely separated. All these changes were ameliorated by administration of spirulina (Group IV). Corneal thickness was nearly normal in Group IV, statistically significantly less than in Group III. It was concluded that spirulina protects against FA-induced corneal injury in rats. Clin. Anat. 31:830-837, 2018. © 2018 Wiley Periodicals, Inc.

A new substitute for formalin: Application to embalming cadavers

The development of formalin-free fixatives is an urgent issue in gross anatomy because of the health hazard and the tissue-hardening actions of formalin. We recently identified the fixative, antimicrobial, and preservative effects of N-vinyl-2-pyrrolidone (NVP), a precursor of the water-soluble macromolecular polymer polyvinylpyrrolidone, in animal experiments. The aim of the present study is to investigate whether NVP solution can be used as an alternative to formalin in human cadaveric dissection. Twelve donated cadavers were infused with NVP via the femoral and common carotid arteries using a peristaltic pump. Experienced teaching staff members in our department dissected the cadavers and examined their macroanatomical properties. The NVP-embalmed corpses showed no sign of decomposition or fungal growth. The bodies remained soft and flexible. Notably, the shoulder, elbow, wrist, phalangeal, hip, knee, cervical spine, and temporomandibular joints were highly mobile, almost equivalent to those of living individuals. The range of motion of most joints was greater in the NVP-fixed than formalin-fixed cadavers. Under the dermis, the subcutaneous fat was markedly reduced and the connective tissues were transparent, so the ligaments, cutaneous nerves, and veins were easily discernible. The abdominal wall and the visceral organs remained pliable and elastic, resembling those of fresh cadavers. The lungs, liver, and gastrointestinal tract were moveable in the thoracic and abdominal cavities and were readily isolated. NVP can be used successfully as a fixative and preservative solution for human cadavers; furthermore, NVP-embalmed bodies could be valuable for learning clinical skills and for training, and for developing innovative medical devices. Clin. Anat. 31:90-98, 2018. © 2017 Wiley Periodicals, Inc.