Reproductive and developmental toxicity of formaldehyde: a systematic review

Personal exposure and health risk assessment of carbonyls in family cars and public transports-a comparative study in Nanjing, China

To evaluate passenger health risks associated with inhalation exposure to carbonyl compounds mainly emitted from decoration materials of vehicles, we tested the carbonyl concentrations in interior air of 20 family cars, 6 metro lines, and 5 buses in the city of Nanjing. To assess non-carcinogenic health risks, we compared the data to the health guidelines of China, US Environmental Protection Agency (EPA), and Office of Environmental Health Hazard Assessment (OEHHA), respectively. To assess carcinogenic risks, we followed a standard approach proposed by the OEHHA to calculate lifetime cancer risks (LCR) of formaldehyde and acetaldehyde for various age groups. The results showed that there are formaldehyde, acetaldehyde, and acrolein concentrations in 40, 35, and 50% of family car samples exceeded the reference concentrations (RfCs) provided by Chinese guidelines (GB/T 27630-2011 and GB/T 18883-2002). Whereas, in the tested public transports, concentrations of the three carbonyls were all below the Chinese RfCs. Fifty and 90% of family cars had formaldehyde and acrolein concentrations exceeding the guidelines of OEHHA. Only one public transport sample (one bus) possesses formaldehyde and acetaldehyde concentrations above the chronic inhalation reference exposure limits (RELs). Furthermore, the assessments of carcinogenic risk of formaldehyde and acetaldehyde showed that lifetime cancer risks were higher than the limits of EPA for some family cars and public transports. In the study, buses and metros appear to be relatively clean environments, with total carbonyl concentrations that do not exceed 126 μg/m³. In family cars, carbonyl levels showed significant variations from 6.1 to 811 μg/m³ that was greatly influenced by direct emissions from materials inside the vehicles. Public transports seemed to be the first choice for resident trips as compared to family cars. Graphical abstract ᅟ.

The relationship between spontaneous abortion and female workers in the semiconductor industry

Background

This study investigated the relationship between job type and the risk for spontaneous abortion to assess the reproductive toxicity of female workers in the semiconductor industry.

Methods

A questionnaire survey was administered to current female workers of two semiconductor manufacturing plants in Korea. We included female workers who became pregnant at least 6 months after the start of their employment with the company. The pregnancy outcomes of 2,242 female workers who experienced 4,037 pregnancies were investigated. Personnel records were used to assign the subjects to one of three groups: fabrication process workers, packaging process workers, and clerical workers. To adjust for within-person correlations between pregnancies, a generalized estimating equation was used. The logistic regression analysis was limited to the first pregnancy after joining the company to satisfy the assumption of independence among pregnancies. Moreover, we stratified the analysis by time period (pregnancy in the years prior to 2008 vs. after 2009) to reflect differences in occupational exposure based on semiconductor production periods.

Results

The risk for spontaneous abortion in female semiconductor workers was not significantly higher for fabrication and packaging process workers than for clerical workers. However, when we stratified by time period, the odds ratio for spontaneous abortion was significantly higher for packaging process workers who became pregnant prior to 2008 when compared with clerical workers (odds ratio: 2.21; 95% confidence interval: 1.01–4.81).

Conclusions

When examining the pregnancies of female semiconductor workers that occurred prior to 2008, packaging process workers showed a significantly higher risk for spontaneous abortions than did clerical workers. The two semiconductor production periods in our study (prior to 2008 vs. after 2009) had different automated processes, chemical exposure levels, and working environments. Thus, the conditions prior to 2008 may have increased the risk for spontaneous abortions in packaging process workers in the semiconductor industry.

Electronic supplementary material

The online version of this article (10.1186/s40557-017-0204-x) contains supplementary material, which is available to authorized users.

The Gulf oil spill, miscarriage, and infertility: the GROWH study

PURPOSE

To examine whether reported exposure to the Gulf oil spill (2010) was related to reproductive reported miscarriage or infertility.

METHODS

1524 women aged 18-45 recruited through prenatal and Women, Infant, and Children (WIC) clinics, and community events were interviewed about their experience of the oil spill and reproductive history. 1434 women had information on outcomes of at least one pregnancy, and 633 on a pregnancy both before and after the spill. Generalized estimating equations were used to examine the relationship between contact with oil and economic and social consequences of the spill with postponement of pregnancy, miscarriage, and infertility (time to pregnancy >12 months or reported fertility issues), with adjustment for age, race, BMI, smoking, and socioeconomic status. Results were compared for pregnancies occurring prior to and after the oil spill.

RESULTS

77 (5.1%) women reported postponing pregnancy due to the oil spill, which was more common in those with high contact with oil or overall high exposure (aOR 2.92, 95% CI 1.31-6.51). An increased risk of miscarriage was found with any exposure to the oil spill (aOR, 1.54, 95% CI 1.17-2.02). Fertility issues were more common in the overall most highly exposed women (aOR 1.88, 1.19-2.95), when the data were limited to those with pregnancies before and after. However, no particular aspect of oil spill exposure was strongly associated with the outcomes, and effects were almost as strong for pregnancies prior to the oil spill.

CONCLUSIONS

The oil spill appears to have affected reproductive decision-making. The evidence is not strong that exposure to the oil spill was associated with miscarriage or infertility.

Genetic variation and risk of DNA damage in peripheral blood lymphocytes of Iranian formaldehyde-exposed workers

Formaldehyde (FA) has given positive results for the genetic damage evaluated in human peripheral blood lymphocytes. Polymorphism plays a special role in the toxicity of chemicals. DNA damage in blood cells was evaluated in workers who were occupationally exposed to FA. This study tested the association of alcohol dehydrogenase III (ADH3) and manganese-superoxide dismutase (Mn-SOD) gene polymorphism, with DNA damage of peripheral blood lymphocytes. Gene polymorphisms were evaluated in 54 workers from melamine dinnerware workshops and 34 workers from dairy production workshops. The control and exposed population were matched based on age, smoking, work history and socioeconomic status. DNA damage was evaluated by alkaline comet assay in the peripheral blood lymphocytes. ADH3 and Mn-SOD genotypes were determined in all workers using polymerase chain reaction–restriction fragment length polymorphism method. DNA damage of lymphocyte cells was significantly higher ( p < 0.001) in the exposed individuals in comparison with the control population. The examinations of the exposed group had revealed significantly higher ( p < 0.01) variant of Val/Val of Mn-SOD compared to control group. In workers with ADH32–2 variant, significantly higher levels of DNA damage ( p < 0.01) were observed than the control population with the same genotype. It could be concluded that enzymes involved in the metabolism of FA and oxidative stress controlling are two important effective parameters for DNA damage of peripheral blood lymphocytes in exposed people. These results are regarded as a pioneer investigation for the management of health risks assessment.

The effect of prenatal TVOC exposure on birth and infantile weight: the Mothers and Children's Environmental Health study

BACKGROUNDVolatile organic compounds (VOCs) might restrict prenatal and postnatal growth. However, the effect of the exposure of prenatal VOCs on postnatal growth has not been studied sufficiently. Thus, we investigated the relationship between the exposure of total volatile organic compounds (TVOCs) during pregnancy and its effects on postnatal growth.METHODSA total of 383 pregnant participants were enrolled from 2006 to 2008. We investigated maternal characteristics using a questionnaire. Personal air samples of TVOCs were obtained in mid or late pregnancy. After these mothers had given birth, 360 singleton newborns were selected and postnatal follow-up data were collected at 6, 12, 24, and 36 months, as well as anthropometric factors including body weight. Multiple general linear and mixed models were applied for statistical analyses.RESULTSThe mean concentration of prenatal exposure to TVOCs was 284.2 μg/m³ and that of formaldehyde was 81.6 μg/m³. The birth weight of newborns decreased significantly with prenatal TVOC exposure (β=-45.89, P=0.04). The adjusted mean body weight was 300 g lower in the high-TVOC group (⩾75th) compared with that in the low-exposure group (<75th).CONCLUSIONThese results indicate that elevated exposure to TVOCs during the prenatal period may adversely influence early postnatal growth.

Evaluation of the sensitivity spectrum of a video tracking system with zebrafish (Danio rerio) exposed to five different toxicants

The aim of this study was to develop a biological early warning system for the detection of aquatic toxicity and test it with five toxicants with distinct chemical nature. This was done in order to verify the spectrum of sensitivities of the proposed system, as well as the potential identification capability of the tested contaminants, using only the analysis of zebrafish's behavior. Six experimental conditions were tested: negative control and five toxicants (bleach, lindane, tributyltin, mercury, and formaldehyde). The exposure time was 45 min, and the concentrations used corresponded to 9% of LC₅₀'s-96 h for the tested compounds, to ensure ecologically relevant results. A total of 108 fish were used, with each individual experimental condition being tested 18 times. A statistical model of diagnosis was used, combining self-organizing map and correspondence analysis. The values of sensitivity, specificity, accuracy, false positive, false negative, positive predictive value (PPV), and negative predictive value (NPV) were calculated. The objectives of the work were accomplished and the system showed a good overall diagnostic performance with 79% in accuracy, 77% in sensitivity, and 88% in specificity. The lowest result of the predictive values was 78% (lindane and mercury), in the case of the NPV, and 86% (bleach and lindane), in the case of the PPV. The best result of the predictive values was 100% (bleach and tributyltin), for the NPV, and 89% (tributyltin), for the PPV. Regarding the five tested toxicants, the system was able to correctly identify the agent responsible for the contamination in 40% of the positive diagnoses.

Correlates of Electronic Cigarettes Use Before and During Pregnancy

Introduction

Electronic cigarette use is rapidly gaining in popularity. However, little is known about correlates and reasons for electronic cigarette use by women of reproductive age, a group for which the safety and efficacy of electronic cigarette use is of particular interest.

Methods

As part of a clinical trial for smoking cessation, we surveyed pregnant smokers about their lifetime use of electronic cigarettes, previous use of any adjunctive treatments for smoking cessation, and use of electronic cigarettes during pregnancy. We examined associations between electronic cigarette use and participant characteristics.

Results

Fifty-three percent (55/103) of participants had previously tried electronic cigarettes. Ever users smoked more cigarettes per day before pregnancy (p = .049), had a greater number of previous quit attempts (p = .033), and were more likely to identify as being Hispanic or non-Hispanic white than never users (p = .027). Fifteen percent of participants (15/103) reported previous use of electronic cigarettes for smoking cessation, which was more common than the use of any specific FDA-approved smoking cessation medication. Fourteen percent of participants (14/103) reported electronic cigarette use during pregnancy, most commonly to quit smoking. A history of substance abuse (p = .043) and more previous quit attempts (p = .018) were associated with electronic cigarette use during pregnancy.

Conclusions

Use of electronic cigarettes to quit smoking may be common in women of reproductive age, including those who are pregnant. More research is needed to determine the risks and benefits of electronic cigarette use in this population of smokers.

Implications

This study shows that electronic cigarettes are used by women of reproductive age, including pregnant smokers. The implications of this finding are that there is an urgent need to examine the risks and benefits of electronic cigarette use, especially by pregnant women. The study also shows that electronic cigarettes are commonly used as a smoking cessation aid in women of reproductive age. The greater likelihood of electronic cigarette use compared to proven adjunctive smoking treatments suggests that electronic cigarettes should be examined as a potential aid to cessation in this population.

Association between formaldehyde exposure and miscarriage in Chinese women

The aim of this study was to assess whether higher plasma formaldehyde concentration existed in women diagnosed with miscarriage and whether it contributed to higher risk of miscarriage in Chinese women.A case-control study was conducted in 118 women with a diagnosed miscarriage at the first trimester and 191 healthy women who delivered at term. Plasma levels of formaldehyde were measured by gas chromatography in conjunction with mass spectrometry after derivatization of the formaldehyde to the pentafluorophenylhydrazone and characteristics of the subjects including age, education level, occupation, family income, home decoration status, and exposure to second-hand smoke were recorded. Logistic regression analyses were performed to investigate the relationship between miscarriage and levels of formaldehyde.Women with miscarriage were comparable to controls in terms of age, education level, occupation, family income, and home decoration status. They were, however, more likely to be exposed to second-hand smoke. Plasma levels of formaldehyde were significantly higher in women with miscarriage (0.0944 ± 0.0105 vs. 0.0239 ± 0.0032 μg/mL, P < .001). Multivariate logistic regression showed that higher level of formaldehyde (odds ratio [OR]: 8.06, 95% confidence interval [CI]: 4.96-13.09) and exposure to second-hand smoke (OR: 3.60, 95% CI: 1.58-8.20) were independently and significantly associated with higher risk of miscarriage.Plasma levels of formaldehyde were significantly higher in women who were diagnosed with miscarriage than those who delivered at term and higher levels of formaldehyde was an independent risk factor for miscarriage, with higher levels being associated with higher risk of miscarriage.

Electronic cigarettes—A review of the physiological health effects

Electronic cigarettes (ECs) are devices that are used recreationally or as smoking cessation tools, and have become increasingly popular in recent years. We conducted a review of the available literature to determine the health effects caused by the use of these devices. A heating element in the EC aerosolizes a solution of propylene glycol, glycerol, nicotine (optional), and flavouring (optional). These compounds are generally harmless on their own. However, upon heating, they produce various carcinogens and irritants. We found that concentrations of these toxicants vary significantly depending on the type of EC device, the type of EC liquid, and the smoking behaviour of the user. Exposure to these vapours can cause inflammation and oxidative damage to in vitro and in vivo cells. EC aerosol can also potentially affect organ systems and especially cardiovascular and lung function. We concluded that EC use causes acute effects on health but not as severe as those of conventional cigarettes (CCs). These devices could, therefore, be of use for smokers of CCs wishing to quit. However, as EC aerosol introduces new toxicants not found in CCs, long-term studies are needed to investigate possible chronic effects associated with EC use.

Indoor air quality in public utility environments-a review

Indoor air quality has been the object of interest for scientists and specialists from the fields of science such as chemistry, medicine and ventilation system design. This results from a considerable number of potential factors, which may influence the quality of the broadly understood indoor air in a negative way. Poor quality of indoor air in various types of public utility buildings may significantly affect an increase in the incidence of various types of civilisation diseases. This paper presents information about a broad spectrum of chemical compounds that were identified and determined in the indoor environment of various types of public utility rooms such as churches, museums, libraries, temples and hospitals. An analysis of literature data allowed for identification of the most important transport paths of chemical compounds that significantly influence the quality of the indoor environment and thus the comfort of living and the health of persons staying in it.

Effects of hesperidin on formaldehyde-induced toxicity in pregnant rats

This experimental study aimed to investigate the protective effect of a bioflavonoid, hesperidin (HP), on formaldehyde (FA)-related pathophysiological and behavioral outcomes in pregnant rats and developmental aspects in their offspring. Female Wistar rats were subjected to perigestational exposure to FA (2 mg/kg/day per os) with a concomitant treatment with HP (50 mg/kg/day per os). Pregnant rats were weighed throughout gestation and tested in two behavioral paradigms (elevated plus-maze and open field) at gestational days (GD) 1, 10 and 19 to evaluate the anxiety-like behavior and locomotive alterations. Another subset of rats was decapitated at GD19 to determine the hematological profile along with cortisol, 17β-estradiol, and progesterone plasma levels. Reproductive and fetal measures and observations were also performed to check for developmental deformities. Significant body weight loss, hemato-immune decline, hormonal changes, anxiety and lethargy signs, locomotor disabilities, reproductive failure and fetal weight decrease were observed in FA-exposed rats. Treatment with HP alleviated the reproductive and fetal weight defects. Its behavioral benefits were only seen at GD1 and 10. This flavanone ameliorated some hematological parameters, decreased cortisol levels and increased 17β-estradiol rates. A potential preventive impact of HP was found against FA toxicity in pregnant rats.

A Critique of Risk Disclosure as the Solution for Minimizing Toxic Exposures in Pregnancy

The issue of pregnant women's exposures to everyday chemicals and the implications for the health of future children are receiving increased attention in popular media and in the academic press. In response, health profession organizations are developing clinical practice guidelines for warning pregnant women about the risks associated with exposures to certain toxics. We evaluate different sides of a risk-avoidance approach for pregnant women in the context of a hypothetical case study involving phthalates and women who work in nail salons. We consider the ubiquitous nature of low-dose exposures and both the positive aspects and limitations of promoting avoidance measures with respect to phthalate exposures. We conclude that a risk-disclosure approach has both practical limitations and equity dimensions which must be factored in to public health guidelines and messaging and the development of clinical practice guidelines. Upstream solutions including regulatory action on chemicals and heightened attention to environmental justice would result in optimal management of this issue.

Formaldehyde Is a Potent Proteotoxic Stressor Causing Rapid Heat Shock Transcription Factor 1 Activation and Lys48-Linked Polyubiquitination of Proteins

Endogenous and exogenous formaldehyde (FA) has been linked to cancer, neurotoxicity, and other pathophysiologic effects. Molecular and cellular mechanisms that underlie FA-induced damage are poorly understood. In this study, we investigated whether proteotoxicity is an important, unrecognized factor in cell injury caused by FA. We found that irrespective of their cell cycle phases, all FA-treated human cells rapidly accumulated large amounts of proteins with proteasome-targeting K48-linked polyubiquitin, which was comparable with levels of polyubiquitination in proteasome-inhibited MG132 controls. Both nuclear and cytoplasmic proteins were damaged and underwent K48-polyubiquitination. There were no significant changes in the nonproteolytic K63-polyubiquitination of soluble and insoluble cellular proteins. FA also rapidly induced nuclear accumulation and Ser326 phosphorylation of the main heat shock-responsive transcription factor HSF1, which was not a result of protein polyubiquitination. Consistent with the activation of the functional heat shock response, FA strongly elevated the expression of HSP70 genes. In contrast to the responsiveness of the cytoplasmic protein damage sensor HSF1, FA did not activate the unfolded protein response in either the endoplasmic reticulum or mitochondria. Inhibition of HSP90 chaperone activity increased the levels of K48-polyubiquitinated proteins and diminished cell viability after FA treatment. Overall, our results indicate that FA is a strong proteotoxic agent, which helps explain its diverse pathologic effects, including injury in nonproliferative tissues.

Increased time-to-pregnancy is associated with domestic work in South Africa

Background

The effects of female occupational exposures on fecundity have not been evaluated in South Africa. The aim of this study was to assess the effects of three specific occupational groups on time-to-pregnancy (TTP).

Methods

This cross-sectional study collected data, by means of a questionnaire, on 1210 women representative of a South African population, and sought information on: TTP for the most recent pregnancy, time-specific information on maternal factors and occupational exposures, as well as some paternal factors. Occupational exposure groups were determined using employment profile prior to the pregnancy. In the risk analysis, domestic workers and teachers were compared to administrative staff. Accidental and unplanned pregnancies were excluded from the analysis and participants who were never pregnant were censored. Discrete-time Cox regression models were built to estimate fecundability ratios (FR).

Results

The median TTP in administrative workers, domestic workers and teachers was 4, 12 and 3 months respectively. After adjusting for a number of potential confounders, TTP was significantly related to occupation at the time of pregnancy attempt. Compared to administrative workers, domestic workers had a significantly lower per-cycle probability of conception (adjusted FR = 0.53; 95 CI 0.32–0.88). The per-cycle probability of conception in teachers compared to administrative workers was not significantly different (adjusted FR = 1.14; 95 CI: 0.75–1.72).

Conclusion

Domestic work was associated with prolonged TTP. Working as a domestic worker in South Africa may affect fecundity.

Formaldehyde exposure inhibits the expression of mammalian target of rapamycin in rat testis

Formaldehyde (FA), a ubiquitous environmental pollutant, has long been suspected of causing adverse male reproductive effects. However, the molecular and cellular mechanisms underlying this phenomenon remain elusive. The overall aim of this study is to clarify the role of mammalian target of rapamycin (mTOR) in male reproductive injuries induced by FA exposure, by which we can further understand the molecular mechanism of FA male reproductive toxicity. In this study, immunohistochemistry, Western blotting, and reverse transcription polymerase chain reaction analysis were used to detect the expression of mTOR molecule in testicular tissues. We found that FA exposure inhibits the expression of mTOR in a dose-dependent manner. Combined with our earlier finding, we found the decreasing expression of mTOR in testicular tissue were consistent with the changes of testicular structure and autophagy levels. In summary, our data suggested that mTOR molecule might be involved in male reproductive injuries induced by FA exposure.

Effects of combined exposure to formaldehyde and benzene on immune cells in the blood and spleen in Balb/c mice

Formaldehyde and benzene are the two major indoor air pollutants due to their prevalence and toxicity. This study aimed to explore the toxic effect on the spleen and relevant immune responses of Balb/c mice caused by exposure to a combination of formaldehyde and benzene. Balb/c mice were divided randomly into five groups (n=9/group): blank control group (Ctrl); solvent ([corn] Oil) control; formaldehyde only (FA, 3mg/m(3)); benzene only (BZ, 150mg/kg BW); and, formaldehyde+benzene group (FA+BZ). Exposures were performed for 8h/day, 5 day/week, for 2 weeks. Tail blood was collected after the final exposure; 24-h later, the mice were euthanized to permit assessment of a variety of immune endpoints. The endpoints' three areas were: (1) in living mice, body weight and delayed-type hypersensitivity (DTH) responses; (2) in blood, immune cell counts and serum antibody levels (serum hemagglutination); and, (3) in spleen samples, reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), caspase-3 (cell apoptosis) levels and lymphocyte proliferation. In this study we fund (1) BZ and FA+BZ exposure can lead to the reduction in the number of some immune cells in peripheral blood; (2) Formaldehyde has certain synergistic effects on benzene-induced cytotoxicity in peripheral blood, (3) FA, BZ and FA+BZ exposure can lead to ROS and GSH depletion in spleen cells, and spleen cell apoptosis (caspase-3 increased) may be one of the downstream events, decreased splenic lymphocyte proliferation; and (4) the FA+BZ combined exposure can lead to the decreased body weight, serum antibody level (by serum hemagglutination assay).

Birth defects in infants born to employees of a microelectronics and business machine manufacturing facility

BACKGROUND

Concerns about solvent releases from a microelectronics/business machine manufacturing facility in upstate New York led to interest in the health of former workers, including this investigation of birth defects in children of male and female employees.

METHODS

Children born 1983 to 2001 to facility employees were enumerated and matched to New York State's Congenital Malformations Registry. Reported structural birth defects were compared with numbers expected from state rates (excluding New York City), generating standardized prevalence ratios (SPRs). Exposure assessors classified employees as ever/never potentially exposed at the facility to metals, chlorinated hydrocarbons, and other hydrocarbons during windows critical to organogenesis (female workers) or spermatogenesis (male workers). Among workers, adjusted prevalence ratios were generated to evaluate associations between potential exposures and specific birth defects.

RESULTS

External comparisons for structural defects were at expectation for infants of male workers (SPR = 1.01; 95% confidence interval [CI], 0.77-1.29; n = 60) and lower for births to female workers (SPR = 0.84; 95% CI, 0.50-1.33; n = 18). Among full-term infants of male workers, ventricular septal defects (VSDs) were somewhat elevated compared with the general population (SPR = 1.58; 95% CI, 0.99-2.39; n = 22). Within the cohort, potential paternal metal exposure was associated with increased VSD risk (adjusted prevalence ratio = 2.70; 95% CI, = 1.09-6.67; n = 7).

CONCLUSION

While overall SPRs were near expectation, paternal exposure to metals (primarily lead) appeared to be associated with increased VSD risk in infants. Take-home of occupational exposures, nonoccupational exposures, and chance could not be ruled out as causes. Case numbers for many defects were small, limiting assessment of the role of occupational exposures. Birth Defects Research (Part A) 106:696-707, 2016. © 2016 Wiley Periodicals, Inc.

Formaldehyde-induced toxicity in the nasal epithelia of workers of a plastic laminate plant

Formaldehyde is a ubiquitous volatile organic compound widely used for various industrial purposes. Formaldehyde was reclassified by the International Agency for Research on Cancer as a human carcinogen, based on sufficient evidence for a casual role for nasopharyngeal cancer. However, the mechanisms by which this compound causes nasopharyngeal cancer are not completely understood. Therefore, we have examined the formaldehyde-induced toxicity in the nasal epithelia of the workers of a plastic laminate plant in Bra, Cuneo, Piedmont region, North-Western Italy, hence in the target site for formaldehyde-related nasal carcinogenesis. We have conducted a cross-sectional study aimed at comparing the frequency of 3-(2-deoxy-β-d-erythro-pentafuranosyl)pyrimido[1,2-α]purin-10(3H)-one deoxyguanosine (M1dG) adducts, a biomarker of oxidative stress and lipid peroxidation, in 50 male exposed workers and 45 male controls using 32P-DNA post-labeling. The personal levels of formaldehyde exposure were analysed by gas-chromatography mass-spectrometry. The smoking status was estimated by measuring the concentrations of urinary cotinine by gas-chromatography mass-spectrometry. The air monitoring results showed that the exposure levels of formaldehyde were significantly greater for the plastic laminate plant workers, 211.4 ± 14.8 standard error (SE) μg m-3, than controls, 35.2 ± 3.4 (SE) μg m-3, P < 0.001. The levels of urinary cotinine were 1064 ± 118 ng ml-1 and 14.18 ± 2.5 ng ml-1 in smokers and non-smokers, respectively, P < 0.001. The M1dG adduct frequency per 108 normal nucleotides was significantly higher among the workers of the plastic laminate plant exposed to formaldehyde, 111.6 ± 14.3 (SE), compared to controls, 49.6 ± 3.4 (SE), P < 0.001. This significant association persisted also when personal dosimeters were used to measure the extent of indoor levels of formaldehyde exposure. No influences of smoking and age were observed across the study population. However, after categorization for occupational exposure, a significant effect was found in the controls, P = 0.018, where the levels of DNA damage were significantly correlated with the levels of urinary cotinine, regression coefficient (β) = 0.494 ± 0.000 (SE), P < 0.002. Our findings indicated that M1dG adducts constitute a potential mechanism of formaldehyde-induced toxicity. Persistent DNA damage contributes to the general decline of the physiological mechanisms designed to maintain cellular homeostasis.

Formaldehyde Stress Responses in Bacterial Pathogens

Formaldehyde is the simplest of all aldehydes and is highly cytotoxic. Its use and associated dangers from environmental exposure have been well documented. Detoxification systems for formaldehyde are found throughout the biological world and they are especially important in methylotrophic bacteria, which generate this compound as part of their metabolism of methanol. Formaldehyde metabolizing systems can be divided into those dependent upon pterin cofactors, sugar phosphates and those dependent upon glutathione. The more prevalent thiol-dependent formaldehyde detoxification system is found in many bacterial pathogens, almost all of which do not metabolize methane or methanol. This review describes the endogenous and exogenous sources of formaldehyde, its toxic effects and mechanisms of detoxification. The methods of formaldehyde sensing are also described with a focus on the formaldehyde responsive transcription factors HxlR, FrmR, and NmlR. Finally, the physiological relevance of detoxification systems for formaldehyde in bacterial pathogens is discussed.

Developing effective worker health and safety training materials: hazard awareness, identification, recognition, and control for the salon industry

OBJECTIVE

In addition to formaldehyde, workers in salons can be exposed to other chemical irritants, sensitizers, carcinogens, reproductive hazards, infectious agents, ergonomic, and other physical hazards. Worker health and safety training is challenging because of current product labeling practices and the myriad of hazards portending risk for a wide variety of health effects.

METHODS

Through a Susan B. Harwood Targeted Topic Training grant from the Occupational Safety and Health Administration and assistance from salon development and training partners, we developed, delivered, and validated a health and safety training program using an iterative five-pronged approach.

RESULTS

The training was well received and resulted in knowledge gain, improved workplace safety practices, and increased communication about health and safety.

CONCLUSIONS

These training materials are available for download from the Occupational Safety and Health Administration's Susan B. Harwood Training Grant Program Web site.

Novel self-healing dental resin with microcapsules of polymerizable triethylene glycol dimethacrylate and N,N-dihydroxyethyl-p-toluidine

OBJECTIVE

Bulk fracture is one of the primary reasons for resin-based dental restoration failures. To date, there has been no report on the use of polymerizable dental monomers with acceptable biocompatibility to develop a resin with substantial self-healing capability. The objectives of this study were to: (1) develop a self-healing resin containing microcapsules with triethylene glycol dimethacrylate (TEGDMA)-N,N-dihydroxyethyl-p-toluidine (DHEPT) healing liquid in poly(urea-formaldehyde) (PUF) shells for the first time, and (2) determine the physical and mechanical properties, self-healing efficiency, and fibroblast cytotoxicity.

METHODS

Microcapsules of polymerizable TEGDMA-DHEPT in PUF were prepared via an in situ polymerization method. Microcapsules were added into a BisGMA-TEGDMA resin at microcapsule mass fractions of 0%, 5%, 10%, 15% and 20%. A flexural test was used to measure composite strength and elastic modulus. A single edge V-notched beam method was used to measure fracture toughness KIC and self-healing efficiency.

RESULTS

Flexural strength and elastic modulus (mean±sd; n=6) of resin containing 5-15% microcapsules were similar to control without microcapsules (p>0.1). Adding microcapsules into the resin increased the virgin KIC, which was about 40% higher at 15% microcapsules than that with 0% microcapsules (p<0.05). Specimens were fractured and healed, then fractured again to measure the healed KIC. A self-healing efficiency of about 65% in KIC recovery was obtained with 10-20% microcapsules. All specimens with 0-20% microcapsules had fibroblast viability similar to control without resin eluents (p>0.1).

SIGNIFICANCE

Self-healing dental resin containing microcapsules with polymerizable TEGDMA-DHEPT healing liquid in PUF shells were prepared for the first time with excellent self-healing capability. These microcapsules and self-healing resins containing them may be promising for dental restorations to heal cracks/damage and increase durability.

Associations between occupation exposure to Formaldehyde and semen quality, a primary study

Formaldehyde (FA), a ubiquitous environmental pollutant, has long been suspected of having male reproductive toxicity. However, FA male reproductive toxicity was inconclusive due to dearth of human studies. Therefore, we sought to investigate whether occupational exposure to FA affects semen quality. Semen quality including five conventional parameters and seven kinematics parameters were compared between 114 male workers occupationally exposed to FA and 76 referents. FA exposure index (FEI) was measured and calculated. Our results showed that sperm progressive motility, total sperm motility, VCL, VSL and VAP were statistically significant decreased in FA exposure workers compared with the referents. Moreover, FEI was significantly negative associated with sperm progressive motility (β = -0.19, P = 0.01) and total sperm motility (β = -0.23, P = 0.004). In addition, a significant elevated risk of abnormal sperm progressive motility were observed in both low- (OR = 2.58; 95% CI: 1.11-5.97) and high-FA-exposed group (OR = 3.41; 95% CI: 1.45-7.92) respectively. Furthermore, a significant increased risk was also estimated for abnormal total sperm motility in both low- (OR = 3.21; 95% CI: 1.24-8.28) and high-FA-exposed group (OR = 4.84; 95% CI: 1.83-12.81) respectively. In conclusion, our study revealed the adverse effects of FA occupation exposure on semen quality, especially on sperm motion parameters.

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

Formalin is commonly used in fixation of cadaveric specimens. Exposure to formaldehyde, a component of formalin and a known carcinogen, during gross anatomy laboratory dissection is a continuing concern for pregnant students and instructors. Since there is little literature on this specific topic, the current review was compiled in the hope of offering recommendations to pregnant students and instructors who are engaged in human anatomical dissection where formalin is used. Relevant articles were obtained through searches of PubMed and Google Scholar for the terms "formaldehyde," "pregnant," "formalin," and "exposure." A literature search was conducted for chemical information and articles about exposure as issued by government regulatory agencies and chemical companies that produce formaldehyde. This led to the compilation of 29 articles each of which included references to previous, relevant, human research. The reviewed literature contains data strongly suggesting that pregnancy can be affected by formaldehyde exposure. Therefore, on the basis our analysis, female students who might be pregnant should avoid formaldehyde exposure, including that in a gross anatomy laboratory. Instructors should find other means of ensuring anatomical competence for these students.

Short-term exposure to formaldehyde promotes oxidative damage and inflammation in the trachea and diaphragm muscle of adult rats

Formaldehyde (FA) is an environmental pollutant widely used in industry. Exposure to FA causes irritation of the respiratory mucosa and is associated with inflammation and oxidative stress in the airways. This study aimed at investigating the oxidative effects on the inflammatory response in the trachea and the diaphragm muscle (DM) of rats exposed to different concentrations of formaldehyde. Twenty-eight Fischer male rats were divided into four groups: control group (CG) exposed to the ambient air; and three groups exposed to the following formaldehyde concentrations of 1% (FA1), 5% (FA5) and 10% (FA10), respectively. The exposure occurred for twenty minutes, three times a day for five days. Oxidative stress analyses were performed by carbonyl protein, lipid peroxidation and catalase activity. The assessment of inflammatory cell influx in both organs and the mucus production in the trachea was carried out. There was an increase of lipid peroxidation in the trachea and the DM of FA1 and FA5 groups compared to the CG and FA10. The oxidation of DM proteins increased in FA10 group compared to CG, FA1 and FA5. The catalase enzyme activity in the DM was reduced in FA1, FA5 and FA10 compared to the CG. Meanwhile, there was a reduction in the enzymatic activity of FA10 compared to the CG in the trachea. The morphometric analysis in the DM demonstrated an influx of inflammatory cells in FA10 compared to the CG. In FA10 group, the tracheal epithelium showed metaplasia and ulceration. In addition, the tracheal epithelium showed more mucus deposits in FA5 compared to CG, FA1 and FA10. The results demonstrated that the exposure to formaldehyde at different concentrations in a short period of time promotes oxidative damage and inflammation in the DM and the trachea and causes metaplasia, ulceration and increased mucus at the latter.

Formaldehyde Crosses the Human Placenta and Affects Human Trophoblast Differentiation and Hormonal Functions

The chorionic villus of the human placenta is the source of specific endocrine functions and nutrient exchanges. These activities are ensured by the syncytiotrophobast (ST), which bathes in maternal blood. The ST arises and regenerates throughout pregnancy by fusion of underlying cytotrophoblasts (CT). Any anomaly of ST formation or regeneration can affect pregnancy outcome and fetal growth. Because of its direct interaction with maternal blood, the ST is sensitive to drugs, pollutants and xenohormones. Ex vivo assays of perfused cotyledon show that formaldehyde, a common pollutant present in furniture, paint and plastics, can accumulate in the human placenta and cross to the fetal compartment. By means of RT-qPCR, immunoblot and immunocytochemistry experiments, we demonstrate in vitro that formaldehyde exerts endocrine toxicity on human trophoblasts, including a decrease in the production of protein hormones of pregnancy. In addition, formaldehyde exposure triggered human trophoblast fusion by upregulating syncitin-1 receptor expression (ASC-type amino-acid transporter 2: ASCT2). Moreover, we show that formaldehyde-exposed trophoblasts present an altered redox status associated with oxidative stress, and an increase in ASCT2 expression intended to compensate for this stress. Finally, we demonstrate that the adverse effects of formaldehyde on trophoblast differentiation and fusion are reversed by N-acetyl-L-cysteine (Nac), an antioxidant.

Investigation on formaldehyde release from preservatives in cosmetics

OBJECTIVE

To understand formaldehyde residue in cosmetics, an investigation on formaldehyde release from eight preservatives (methenamine - MA, paraformaldehyde - PF, poly(p-toluenesulfonamide-co-formaldehyde) -PTSAF, quaternium-15 - QU, imidazolidinyl urea - IU, diazolidinyl urea - DU, dimethyloldimethyl hydantoin - DMDM and bronopol - BP) under various conditions was performed.

METHODS

The concentration of released formaldehyde was determined by high-performance liquid chromatography with photodiode array detection after derivatization with 2,4-dinitrophenylhydrazine.

RESULTS

The amounts of formaldehyde release were in the order of PF > DU > DMDM ≈ QU ≈ IU > MA > BP > PTSAF. The releasing amounts of formaldehyde were the highest in the presence of aqueous matrices for the releasers except QU and IU, and the releasing effect was also relative to pH. More formaldehyde was released with longer storage time and higher temperature. Furthermore, all preservatives in cosmetic matrices released fewer amounts of formaldehyde than in pure aqueous or organic matrices, and the formaldehyde-releasing amounts were also cosmetic specific.

CONCLUSION

Formaldehyde release was dependent on the matrix, pH, time and mainly temperature, and the releasing effect was also cosmetic specific.

Formaldehyde exposure induces autophagy in testicular tissues of adult male rats

Formaldehyde, a ubiquitous environmental pollutant, has long been suspected of causing adverse male reproductive effects. However, the molecular and cellular mechanisms underlying this phenomenon remain elusive. The overall aim of this study is to clarify the role of autophagy in male reproductive injuries induced by formaldehyde exposure, by which we can further understand the molecular mechanism of spermatogenesis and develop new targets for prevention and treatment of male infertility. In this study, electron microscopy, Western blot, and RT-PCR analysis were used to detect autophagy in testicular tissues. Moreover, testicular weights, histopathology, and morphometry were used to evaluate the reproductive injuries of formaldehyde exposure. We found that formaldehyde exposure-induced autophagy in testicular tissues was dose dependent. Increasing autophagosomes in spermatogenetic cells was observed by electron microscopy in formaldehyde exposure group. In addition, RT-PCR and Western blot analysis showed the transcription levels of the LC3-II, as well as the conversion from LC3-I to LC3-II, an indicator of autophagy, significantly increased in testicular tissue of formaldehyde exposure group in a dose dependent manner when compared with those in control group. Furthermore, the alterations of autophage were basically consistent with the changes in testicular weight and morphologic findings. In summary, formaldehyde exposure triggered autophagy, and autophagy may be a scathing factor responsible for male reproductive impairment induced by formaldehyde.

Chromosome-wide aneuploidy study of cultured circulating myeloid progenitor cells from workers occupationally exposed to formaldehyde

Formaldehyde (FA) is an economically important industrial chemical to which millions of people worldwide are exposed environmentally and occupationally. Recently, the International Agency for Cancer Research concluded that there is sufficient evidence that FA causes leukemia, particularly myeloid leukemia. To evaluate the biological plausibility of this association, we employed a chromosome-wide aneuploidy study approach, which allows the evaluation of aneuploidy and structural chromosome aberrations (SCAs) of all 24 chromosomes simultaneously, to analyze cultured myeloid progenitor cells from 29 workers exposed to relatively high levels of FA and 23 unexposed controls. We found statistically significant increases in the frequencies of monosomy, trisomy, tetrasomy and SCAs of multiple chromosomes in exposed workers compared with controls, with particularly notable effects for monosomy 1 [P = 6.02E-06, incidence rate ratio (IRR) = 2.31], monosomy 5 (P = 9.01E-06; IRR = 2.24), monosomy 7 (P = 1.57E-05; IRR = 2.17), trisomy 5 (P = 1.98E-05; IRR = 3.40) and SCAs of chromosome 5 (P = 0.024; IRR = 4.15). The detection of increased levels of monosomy 7 and SCAs of chromosome 5 is particularly relevant as they are frequently observed in acute myeloid leukemia. Our findings provide further evidence that leukemia-related cytogenetic changes can occur in the circulating myeloid progenitor cells of healthy workers exposed to FA, which may be a potential mechanism underlying FA-induced leukemogenesis.

Phenotypic characterization and risk factors for microtia in East China, a case-control study

OBJECTIVE

Although congenital microtia has been reported in various studies, little is known about the etiology of isolated and sporadic cases. The aim was to analyze potential risk factors for isolated and sporadic microtia using case-control study in East China.

METHODS

The study analyzed data from the hospital-based recruitment for deliveries between 2007 and 2013. Nine hundred eleven patients with microtia enrolled in the phenotypic characterization analysis, and then were adjusted by sex, age, region, syndrome and family history to compare with 562 random normal controls for potential risk factors.

RESULTS

Microtia is observed more often in males (69.7%), and the cases were typically unilateral (74.0%), right-sided (57.2%), sporadic (92.0%) and isolated (69.5%). Mothers of children with microtia were more likely to have suffered a periconceptional cold-like syndrome as well as to have had a history of previous spontaneous abortion. Inflammatory infection (aOR, 3.56; 95% CI, 2.07-6.13) and chemical exposure (aOR, 2.77; 95% CI, 1.78-4.32) was associated with a higher risk of microtia. However, threatened abortion was not the risk factor (aOR, 1.14; 95% CI, 0.78-1.67), using progesterone may increase the risk (aOR, 1.92; 95% CI, 1.03-3.59).

CONCLUSION

The results of phenotypic characterization analysis were similar to other studies. By controlling the effects of potential confounders, some risk factors could be teratogens of isolated and sporadic microtia in East China.

5-Fluorouracil-lipid conjugate: potential candidate for drug delivery through encapsulation in hydrophobic polyester-based nanoparticles

The encapsulation of 5-fluorouracil (5-FU) in hydrophobic polymeric materials is made feasible by a lipid-based prodrug approach. A lipid-5-FU conjugate of 5-FU with palmitic acid was synthesized in two-step process. A synthesized dipalmitoyl derivative (5-FUDIPAL) was characterized using Fourier transform infrared spectroscopy and (1)H-nuclear magnetic resonance. The 5-FUDIPAL was encapsulated in polyester-based polymers by the double emulsion-solvent evaporation method. The nanoparticles were characterized by scanning electron microscopy, transmission electron microscopy and dynamic light scattering. The thermal stability was assessed by differential scanning calorimetry data. In vitro release kinetics measurements of the drug from nanoparticles showed the controlled release pattern over a period of time. Cytotoxicity measurements by MTT assay confirmed that dipalmitoyl derivative in nano formulation successfully inhibited the cell growth. Thus the combined physical and biological evaluation of the different polyester-based nanoparticle containing the modified drug showed a facile approach to delivering 5-FU to the tumour site with enhanced efficacy.

Maternal occupation and term low birth weight in a predominantly latina population in los angeles, california

OBJECTIVES

Focusing on Latinas, we investigated whether maternal occupations during pregnancy increase term low birth weight (TLBW) (less than 2500 g; 37 weeks or more).

METHODS

In a case-control study (n = 1498) nested within a 2003 birth cohort (n = 58,316) in Los Angeles County, California (65% Latina), we assessed the influence of maternal occupation on TLBW, using Occupational Codes based on the 2000 US Census Occupational Classification System.

RESULTS

Odds ratios (ORs) for TLBW were increased among women working during pregnancy in "transportation and material moving operations" (adjusted OR = 3.28; 95% confidence interval = 1.00 to 10.73), "food preparation and serving occupations" (adjusted OR = 3.03, 95% confidence interval = 1.21 to 7.62), or "production occupations" (adjusted OR = 2.63, 95% confidence interval = 1.01 to 6.82) compared with "office occupations;" 73% to 93% of women working in these higher-risk jobs were immigrant Latinas.

CONCLUSIONS

Working conditions in various jobs held mainly by first-generation immigrant Latinas increase risks for TLBW and need to be addressed to develop strategies to reduce TLBW.

Lymphohematopoietic cancers induced by chemicals and other agents and their implications for risk evaluation: An overview

Lymphohematopoietic neoplasia are one of the most common types of cancer induced by therapeutic and environmental agents. Of the more than 100 human carcinogens identified by the International Agency for Research on Cancer, approximately 25% induce leukemias or lymphomas. The objective of this review is to provide an introduction into the origins and mechanisms underlying lymphohematopoietic cancers induced by xenobiotics in humans with an emphasis on acute myeloid leukemia, and discuss the implications of this information for risk assessment. Among the agents causing lymphohematopoietic cancers, a number of patterns were observed. Most physical and chemical leukemia-inducing agents such as the therapeutic alkylating agents, topoisomerase II inhibitors, and ionizing radiation induce mainly acute myeloid leukemia through DNA-damaging mechanisms that result in either gene or chromosomal mutations. In contrast, biological agents and a few immunosuppressive chemicals induce primarily lymphoid neoplasms through mechanisms that involve alterations in immune response. Among the environmental agents examined, benzene was clearly associated with acute myeloid leukemia in humans, with increasing but still limited evidence for an association with lymphoid neoplasms. Ethylene oxide and 1,3-butadiene were linked primarily to lymphoid cancers. Although the association between formaldehyde and leukemia remains controversial, several recent evaluations have indicated a potential link between formaldehyde and acute myeloid leukemia. The four environmental agents examined in detail were all genotoxic, inducing gene mutations, chromosomal alterations, and/or micronuclei in vivo. Although it is clear that rapid progress has been made in recent years in our understanding of leukemogenesis, many questions remain for future research regarding chemically induced leukemias and lymphomas, including the mechanisms by which the environmental agents reviewed here induce these diseases and the risks associated with exposures to such agents.

Inactivation kinetics of formaldehyde on N-acetyl-β-D-glucosaminidase from Nile tilapia (Oreochromis niloticus)

Formaldehyde is a widely used sanitizer in aquaculture in China, while the appropriate concentration is not available to be used effectively and without damage to tilapia much less to its reproductive function. N-acetyl-β-D-glucosaminidase (EC 3.2.1.52, NAGase), hydrolyzing the oligomers of N-acetyl-β-D-glucosamine into monomer, is proved to be correlated with reproduction of male animals. In this paper, NAGase from spermary of tilapia was chosen as the material to study the effects of formaldehyde on its activity in order to further investigate the effects of formaldehyde use on tilapia reproduction. The results showed the relationship between the residual enzyme activity and the concentration of formaldehyde was concentration dependent, and the IC50 value was estimated to be 3.2 ± 0.1 %. Appropriate concentration of formaldehyde leaded to competitive reversible inhibition on tilapia NAGase. Moreover, formaldehyde could reduce the thermal and pH stability of the enzyme. The inactivation kinetics of formaldehyde on the enzyme was studied using the kinetic method of substrate reaction. The inactivation model was setup, and the rate constants were determined. The results showed that the inactivation of formaldehyde on tilapia NAGase was a slow, reversible reaction with partially residual activity. The results will give some basis to determine the concentration of formaldehyde used in tilapia culture.

Central nervous system toxicity after acute oral formaldehyde exposure in rabbits

Formaldehyde (FA) is one of the most widely used chemical compounds in industrial field. It is described as toxic, particularly to the nervous system, the urogenital system, and the respiratory tracts. In this study, we determined the effects of acute oral exposure to FA in rabbit brain tissue. A total of 16 rabbits were selected and divided into 2 groups: formaldehyde group (group F) and control group (group C). FA was administered to group F at a rate of 40 mg/kg/day via a nasogastric tube for 5 days. Saline was similarly administered to the eight controls. All the animals were euthanized after 5 days of exposure, and brain tissue samples were collected in 10% neutral formalin and embedded in paraffin. To investigate the effects of FA on the apoptotic process, we examined active caspase-3, Bax, and Bcl-2 immunohistochemical expression and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate –biotin nick-end labeling (TUNEL) reactivity in the rabbit brains. In addition, glial fibrillary acidic protein (GFAP) was biochemically assessed in brain tissue samples for neurotoxicity. We found that FA treatment caused a significant decrease in Bcl-2 expression and an increase in active caspase-3 and Bax expressions as well as an increase in the number of TUNEL-positive apoptotic cells. The GFAP level was found to be significantly higher in group F. In conclusion, acute oral exposure to FA caused DNA damage, apoptosis, and neuronal injury in the rabbit brains.

Occupational chemical exposures among cosmetologists: risk of reproductive disorders

More research is needed to understand possible occupational reproductive risks for cosmetologists, specifically hairdressers and nail technicians, two occupations that often share workspace and exposure to hair dyes and nail polish. Cosmetologists are predominantly females of reproductive age; thus, they may be at higher risk for the effects of exposure to reproductive toxins. The purpose of this article is to inform nurses and public health professionals about occupational exposures for cosmetologists and discuss interventions to reduce the risks of reproductive disorders among susceptible worker populations.

Inhaled formaldehyde induces DNA-protein crosslinks and oxidative stress in bone marrow and other distant organs of exposed mice

Formaldehyde (FA), a major industrial chemical and ubiquitous environmental pollutant, has been classified as a leukemogen. The causal relationship remains unclear, however, due to limited evidence that FA induces toxicity in bone marrow, the site of leukemia induction, and in other distal organs. Although induction of DNA-protein crosslinks (DPC), a hallmark of FA toxicity, was not previously detected in the bone marrow of FA-exposed rats and monkeys in studies published in the 1980s, our recent studies showed increased DPC in the bone marrow, liver, kidney, and testes of exposed Kunming mice. To confirm these preliminary results, in the current study we exposed BALB/c mice to 0, 0.5, 1.0, and 3.0 mg m(-3) FA (8 hr per day, for 7 consecutive days) by nose-only inhalation and measured DPC levels in bone marrow and other organs of exposed mice. As oxidative stress is a potential mechanism of FA toxicity, we also measured glutathione (GSH), reactive oxygen species (ROS), and malondialdehyde (MDA), in the bone marrow, peripheral blood mononuclear cells, lung, liver, spleen, and testes of exposed mice. Significant dose-dependent increases in DPC, decreases in GSH, and increases in ROS and MDA were observed in all organs examined (except for DPC in lung). Bone marrow was among the organs with the strongest effects for DPC, GSH, and ROS. In conclusion, exposure of mice to FA by inhalation induced genotoxicity and oxidative stress in bone marrow and other organs. These findings strengthen the biological plausibility of FA-induced leukemogenesis and systemic toxicity.

Occupational chemical exposures among cosmetologists: risk of reproductive disorders

More research is needed to understand possible occupational reproductive risks for cosmetologists, specifically hairdressers and nail technicians, two occupations that often share workspace and exposure to hair dyes and nail polish. Cosmetologists are predominantly females of reproductive age; thus, they may be at higher risk for the effects of exposure to reproductive toxins. The purpose of this article is to inform nurses and public health professionals about occupational exposures for cosmetologists and discuss interventions to reduce the risks of reproductive disorders among susceptible worker populations.