Systematic Review of Screening and Surveillance Programs to Protect Workers from Nanomaterials.
BACKGROUND
Screening and surveillance approaches for workers exposed to nanomaterials could aid in early detection of health effects, provide data for epidemiological studies and inform action to decrease exposure. The aim of this review is to identify such screening and surveillance approaches, in order to extract available data regarding (i) the studies that have successfully been implemented in present day, (ii) identification of the most common and/or toxic nano-related health hazards for workers and (iii) possible exposure surveillance markers. This review contributes to the current understanding of the risk associated with nanomaterials by determining the knowledge gap and making recommendations based on current findings.


METHODS
A systematic review was conducted. PubMed and Embase were searched to identify articles reporting on any surveillance-related study that described both exposure to nanomaterials and the health indicators that were measured. Four reviewers worked in pairs to independently assess the eligibility of studies and risk of bias before extraction of data. Studies were categorised according to the type of study and the medical surveillance performed, which included the type of nanomaterial, any exposure details provided, as well as health indicators and biomarkers tested.


RESULTS
Initially 92 studies were identified, from which 84 full texts were assessed for eligibility. Seven studies met all the inclusion criteria, i.e. those performed in Taiwan, Korea, Czech Republic and the US. Of these, six compared health indicators between exposed and unexposed workers and one study described a surveillance program. All studies were at a high risk of bias. Workers were exposed to a mix of nanomaterials in three studies, carbon-based nanomaterials in two studies, nano-silver in one study and nano-titanium oxide in the other study. Two studies did not find a difference in biomarkers between exposed and unexposed workers. In addition, differences in early effects on pulmonary function or neurobehavioral tests were not observed. One study found an increased prevalence of allergic dermatitis and "sneezing" in the exposed group.


CONCLUSIONS
This review of recently published data on surveillance studies proves that there is a gap in the current knowledge, where most of the surveillance-related studies reported do not follow a set format that provides the required information on ENM characterisation, the type of exposure and the measured indicators/biomarkers. Hence, there is very low quality evidence that screening and surveillance might detect adverse health effects associated with workplace exposure. This systematic review is relevant because it proves that, although surveillance programs have been initiated and preliminary results are being published, the current studies are actually not answering the important questions or solving the overall problem regarding what the potential health hazards are among workers either handling or potentially exposed to ENMs. The recommendations, thus proposed, are based on an obvious need for (i) exposure registries, where longitudinal follow-up studies should inform surveillance, (ii) known exposure measurements or summary indices for ENMs as a reference (iii) validation of candidate biomarkers and (iv) studies that compare the effects of these surveillance approaches to usual care, e.g. those commonly followed for bulk-size hazardous materials.
Department of Toxicology and Biochemistry, National Institute for Occupational Health, National Health Laboratory Service, Johannesburg, South Africa.
Mary
M
Gulumian
Finnish Institute of Occupational Health, Helsinki, Finland.
Jos
J
Verbeek
Department of Toxicology and Biochemistry, National Institute for Occupational Health, National Health Laboratory Service, Johannesburg, South Africa.
Charlene
http://orcid.org/0000-0002-3049-0392
C
Andraos
Department of Toxicology and Biochemistry, National Institute for Occupational Health, National Health Laboratory Service, Johannesburg, South Africa.
Natasha
N
Sanabria
Department of Epidemiology and Surveillance, National Institute for Occupational Health, National Health Laboratory Service, Johannesburg, South Africa.|School of Public Health, Faculty of Health Science, University of the Witwatersrand, Johannesburg, South Africa.
Pieter
P
de Jager
D015415:Biomarkers / Q000032:analysis; D006281:Health Occupations / Q000706:statistics & numerical data*; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D049329:Nanostructures / Q000506:poisoning*; D009784:Occupational Diseases / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D016273:Occupational Exposure / Q000009:adverse effects*; D011159:Population Surveillance / Q000379:methods*; D018570:Risk Assessment / Q000379:methods / Q000706:statistics & numerical data; D012307:Risk Factors
D015415:Biomarkers