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- 11.4.2 Neurological effects
- Genotoxicity
- Carcinogenicity
Community exposureIn a survey of 1726 occupants of homes containing urea-formaldehyde foam insulation (UFFI) and 720 residents in control homes with median formaldehyde levels of 38 ppb (maximum 227 ppb) and 31 ppb (maximum 172 ppb), respectively, no effects on lung parameters were observed (Broder et al., 1988). In contrast, levels of peak expiratory flow rates (PEFR) decreased linearly in 298 children (6 - 15 years old) exposed to 60 - 140 ppb formaldehyde in the home (Krzyzanowski et al., 1990). The decrease at 60 ppb was equivalent to 22% of the PEFR of non-exposed children while at 30 ppb it was 10%. In the same survey, a small transient decrement in PEFR was seen in adults (> 16 years old) only in the morning, and mainly in smokers. The prevalence of self-reported symptoms, such as eye, nose and throat irritation was determined in these community studies. There were increases in prevalence of symptoms primarily at exposure > 120 ppb (> 0.14 mg/m3) in the study by Broder et al. (1988). However, in this study, health complaints of residents in UFFI homes significantly decreased after remediation (i.e. UFFI removal) although levels of formaldehyde were unchanged. No increase in self-reported symptoms was observed in the study by Krzyzanowski et al. (1990), though, in contrast, the prevalence in physician-reported chronic bronchitis or asthma increased in children (6 - 15 years old) exposed to 60 – 140 ppb formaldehyde, especially in those exposed to environmental tobacco smoke. A further study investigated the reported health complaints (eye irritation, nose/throat irritation, and headaches) in nearly 2000 residents in mobile and conventional homes (Ritchie & Lehnan, 1987). A higher prevalence for all symptoms was reported at concentrations > 300 ppb (> 0.36 mg/m3) formaldehyde, with eye irritation the most frequently reported health effect; 89% of residents exposed to this concentration reported eye irritation. The proportion of the study group reporting eye irritation below 100 ppb (0.12 mg/m3) was low, at 1% of residents. Additionally, in the study investigating community exposure by Broder et al. (1988), a small transient increase in the incidence of nasal epithelial squamous metaplasia was seen in UFFI-subjects intending to have their UFFI removed; 18% compared to 15% in controls. 11.4.2 Neurological effectsEvidence of neurological symptoms and impaired performance in neurobehavioral tests were seen in cross-sectional surveys of histology technicians exposed to gaseous formaldehyde in a series of studies by the same investigators (Kilburn et al., 1985b, 1987, 1989; Kilburn & Warshaw, 1992; Kilburn, 1994). However, co-exposure to solvents, such as xylene, toluene and chloroform, which are known to produce neurotoxic effects in humans, prevent any reliable conclusions being drawn from the data on the neurotoxic potential of formaldehyde.
Surveys are available that investigated genetic effects in peripheral lymphocytes, nasal and buccal mucosal cells of workers occupationally exposed to formaldehyde. In studies assessing peripheral lymphocytes, no increased incidence in either chromosome aberrations, sister chromatid exchanges (SCE) or micronucleated cells (MN) were seen in 15 workers manufacturing or processing formaldehyde (Fleig et al., 1982), 30 medical students (Vasudeva & Anand, 1996), 23 anatomy students (Ying et al., 1997; 1999) and 6 pathology students (Thomson et al., 1984). Additionally, no increased incidence of DNA-protein cross-links was seen in 10 furniture workers (Zhitkovich et al., 1996). An increased incidence in SCE in peripheral lymphocytes was seen in 90 pathology students (Shaham et al., 2002), 13 workers reported to be regularly exposed to formaldehyde (Shaham et al., 1997), 8 anatomy students (Yager et al., 1986) and 31 workers exposed to phenol-formaldehyde resins (Suskov & Sazonova, 1982). An increased incidence in chromosome aberrations, SCE and MN was seen in 13 anatomy students (He et al., 1998), while an increased incidence in MN, but not SCE, was observed in 29 mortuary students (Suruda et al., 1993). A study of 20 paper workers reported an increased incidence in chromosome aberrations but not SCE (Bauchinger & Schmid, 1985), however, this study has been criticised for the statistical analysis used, and the findings were considered incidental (Engelhardt et al., 1987). An increased incidence in chromosome aberrations was reported in a study in children (Dobias et al., 1988) and a study of workers (Kitaeva et al., 1996). However, only limited details were provided for these studies, which were reported in abstract form only. An increased incidence in DNA-protein-cross link was also seen in 12 workers, reported to be regularly exposed to formaldehyde (Shaham et al., 1997). In studies investigating the incidence of MN in nasal and buccal cells, an increased incidence was seen in buccal but not nasal cells in studies of 29 and 28 mortuary students (Suruda et al., 1993; Titenko-Holland et al., 1996), while an increase was seen in both cell types in 25 anatomy students (Ying et al., 1997). An increased incidence in MN in nasal cells was also seen in 15 wood workers (Ballarin et al., 1992). An increased incidence in MN in buccal cells was reported in anatomy technicians and anatomy students, however only limited details are available for this Russian study, as only the abstract was reported in English (Kitaeva et al., 1996).
The finding in the early 1980s of tumours in the nasal tract of rats exposed to formaldehyde in inhalation studies led to concerns for workers occupationally exposed to formaldehyde. Extensive epidemiological studies investigating respiratory tract cancers have since been conducted in workers. These studies, that include cohort mortality studies and case-control studies in industrial workers and professionals, have examined the incidence of cancers in the nasal tract, pharynx or lungs. An overview of three meta-analyses of these numerous epidemiology studies is presented below (Blair et al., 1990a, Partanen, 1993, and Collins et al., 1997). A more comprehensive summary of these studies can be found in Table 9 and 10 in the CICAD (IPCS, 2002) review, which is attached in Appendix 3. Additionally, recent case-control and cohort studies (post-1998), investigating the incidence of upper respiratory tract cancers in workers occupationally exposed to formaldehyde (Armstrong et al., 2000; Laforest et al., 2000; Vaughan et al., 2000; Hildesheim et al. 2001; Marsh et al., 2002; Berrino et al., 2003; Coggon et al., 2003; Elci et al., 2003; Hauptman et al., 2003; 2004; Pinkerton et al., 2004), and a meta-analysis of 12 case-control studies investigating the incidence of sinonasal cancers (Luce et al., 2002), are also presented in Section 11.6.1. Possible associations between occupational exposure to formaldehyde and non- respiratory tract cancers have also been investigated to a lesser extent. In studies investigating increased risks of various non-respiratory cancers, such as melanoma, brain, connective tissue, pancreatic, and colon, increased risks have been occasionally observed but without any consistent pattern (e.g. Stroup et al., 1986; Stayner et al., 1988; Hayes et al., 1990; Holly et al., 1996; Dumas et al., 2000). However, recently data has been published (including updates of major cohort studies of industrial workers) that report a relationship between formaldehyde exposure and lymphohematopoietic cancers (specifically leukaemia). Since this cancer type was not specifically evaluated in the CICAD (IPCS, 2002), a review of all the available data is presented in Section 11.6.2. Additionally, a recently published case-control study and meta-analyses investigating the association between formaldehyde exposure and pancreatic cancer are also presented in Section 11.6.2. Directory: data -> assets -> word doc -> 0006 word doc -> Commonwealth of Australia 2002 word doc -> Commonwealth of Australia 2000 word doc -> Priority Existing Chemical word doc -> Rail safety news issue 6 – October 2011 word doc -> Review of Multiple Chemical Sensitivity: Identifying 0006 -> Board Endorsed October 2009 amended 13-09-11 with extra units 0006 -> Rt Hon Andrew Lansley cbe mp secretary of State for Health 0006 -> Environmental Approvals Application Form Use this form Download 5.77 Mb. Share with your friends:
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