scholarly journals An Interdisciplinary Framework for Derivation of Occupational Exposure Limits

2021 ◽  
Author(s):  
Laura Maurer ◽  
Melannie Alexander ◽  
Ammie N Bachman ◽  
Fabian Alexander Grimm ◽  
R. Jeffrey Lewis ◽  
...  
Keyword(s):  
Occupational Exposure ◽  
Health And Safety ◽  
Occupational Exposures ◽  
Problem Formulation ◽  
Worker Safety ◽  
Weight Of Evidence ◽  
Exposure Limits ◽  
Fundamental Parameters ◽  
Exposure Limit ◽  
Governmental Institutions

Protecting the health and safety of workers in industrial operations is a priority of the utmost importance. One of the fundamental parameters relied upon to ensure worker safety is an occupational exposure limit (OEL), which is based on empirical data from animal or observational human studies. There are various guidelines for the derivation and implementation of OELs globally, with a range of stakeholders (including regulatory bodies, governmental institutions, various expert groups, etc) providing such guidance. The purpose of this manuscript is not to review or provide commentary on existing guidance, but rather to share our learnings from a multidisciplinary approach to the OEL derivation process (from problem formulation to uncertainty analysis). The technical assessment that is foundational to the development of a scientifically-derived OEL follows the same sequence of steps as other types of risk assessment: (1) problem formulation, (2) literature review, (3) weight of evidence considerations, (4) point of departure (PoD) selection/derivation, (5) application of assessment factors, and the final step, derivation of the OEL. This manuscript describes a technical framework by which available data relevant for occupational exposures is compiled, analyzed, and utilized to inform safety threshold derivation applicable to OELs.

scholarly journals Setting occupational exposure limits for antimicrobial agents: A case study based on a quaternary ammonium compound-based disinfectant

2020 ◽  
Vol 36 (9) ◽  
pp. 619-633
Author(s):  
G Scott Dotson ◽  
Jason T Lotter ◽  
Rachel E Zisook ◽  
Shannon H Gaffney ◽  
Andrew Maier ◽  
...  
Keyword(s):  
Occupational Exposure ◽  
Quaternary Ammonium ◽  
Antimicrobial Agents ◽  
Weight Of Evidence ◽  
Ammonium Compound ◽  
Occupational Exposure Limits ◽  
Exposure Limits ◽  
Viral Pathogen ◽  
Selection Of

Antimicrobial agents have become an essential tool in controlling the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and guidelines on their use have been issued by various public health agencies. Through its Emerging Viral Pathogen Guidance for Antimicrobial Pesticides, the US Environmental Protection Agency has approved numerous surface disinfectant products for use against SARS-CoV-2. Despite their widespread use and range of associated health hazards, the majority of active ingredients in antimicrobial products, such as surface disinfectants, lack established occupational exposure limits (OELs) to assist occupational health professionals in characterizing risks from exposures to these chemicals. Based on established approaches from various organizations, a framework for deriving OELs specific to antimicrobial agents was developed that relies on a weight-of-evidence evaluation of the available data. This framework involves (1) a screening-level toxicological assessment based on a review of the existing literature and recommendations, (2) identification of the critical adverse effect(s) and dose–response relationship(s), (3) identification of alternative health-based exposure limits (HBELs), (4) derivation of potential OELs based on identified points of departure and uncertainty factors and/or modification of existing alternative HBELs, and (5) selection of an appropriate OEL. To demonstrate the use of this framework, a case study is described for selection of an OEL for a disinfectant product containing quaternary ammonium compounds (quats). Three potential OELs were derived for this product based on irritation toxicity data, developmental and reproductive toxicity (DART) data, and modification of an existing HBEL. The final selected OEL for the quats-containing product was 0.1 mg/m3, derived from modification of an existing HBEL. This value represented the lowest resulting value of the three approaches, and thus, was considered protective of irritation and potential DART.

Occupational Exposure Risk for Swine Workers in Confined Housing Facilities

2019 ◽  
Vol 25 (1) ◽  
pp. 37-50 ◽  
Author(s):  
Alvin C. Alvarado ◽  
Bernardo Z. Predicala
Keyword(s):  
Hydrogen Sulfide ◽  
Occupational Exposure ◽  
Weighted Average ◽  
Respirable Dust ◽  
Exposure Risk ◽  
Exposure Limits ◽  
Exposure Limit ◽  
Short Term Exposure ◽  
Swine Workers ◽  
Time Weighted Average

Abstract. Extended exposure of swine barn workers to noise and airborne contaminants has been reported to be associated with various health problems. In this study, the actual exposure of workers to respirable dust, gases (ammonia and hydrogen sulfide), and noise in swine production operations was monitored in order to determine the contribution of specific activities in the barn to potential adverse health impacts to swine workers. Selected workers in a swine barn facility were outfitted with a personal monitoring system that included a respirable dust sampler, ammonia (NH3) and hydrogen sulfide (H2S) gas monitors, and a noise dosimeter as they performed their regular duties during their workday. From a total of 50 monitoring days spanning winter and summer months, results showed that the occupational exposure of swine workers to respirable dust, NH3, H2S, and noise while performing their daily assigned tasks was generally below the respective time-weighted average exposure limits for each hazard. However, a number of tasks showed high likelihood for elevated occupational exposure risk. Respirable dust concentrations exceeded the time-weighted average limit of 3 mg m-3 while feeding and weighing pigs. These activities also exceeded the short-term exposure limit (35 ppm) for NH3. Dangerous levels of H2S were generated when draining manure from manure collection pits in the production rooms. Noise levels exceeded the recommended 15 min exposure limit (100 dBA) when weighing and loading pigs for market. The occupational exposure risks for workers to barn contaminants can be reduced through measures that control the generation of contaminants at their source, by removing generated contaminants from the work environment, as well as by outfitting the workers with protective devices that prevent personal exposure to contaminants. Keywords: Ammonia, Barn worker, Dust, Hydrogen sulfide, Noise, Occupational exposure, Risk, Swine.

Occupational exposure to extremely low-frequency magnetic fields near 20 kV, 3-phase shunt reactors at substations

2018 ◽  
Vol 53 (2) ◽  
pp. 149-152
Author(s):  
H. Pirkkalainen ◽  
T. Heiskanen ◽  
M. Penttilä ◽  
J. Elovaara ◽  
L. Korpinen
Keyword(s):  
Occupational Exposure ◽  
Magnetic Flux ◽  
Electromagnetic Fields ◽  
Health And Safety ◽  
Low Frequency ◽  
Worker Safety ◽  
Magnetic Flux Density ◽  
Eu Directive ◽  
Action Value ◽  
Shunt Reactors

Directive 2013/35/EU of the European Parliament and Council, among other things, sets values for the occupational exposure of workers regarding the health and safety risks arising from electromagnetic fields. In order to ensure worker safety, the Finnish national grid operator, Fingrid Oyj, conducted several measurements of electromagnetic fields at its substations. One of the goals of the measurements was to ensure that a magnetic flux density of 1000 µT (rms), set as the lower action value by the EU directive, was not reached in any location accessible to substation workers. The highest magnetic flux densities at substations can be found near shunt reactors and their cables, which is why the measurements were focused on those areas. The lower action value of 1000 µT (rms) was surpassed at two locations. This discovery led to immediate actions to prevent workers from accessing these locations.

Nitroethane Documentation of proposed values of occupational exposure limits (OELs)

2017 ◽  
Vol 33 (1(91)) ◽  
pp. 97-113
Author(s):  
Andrzej Sapota ◽  
Małgorzata Skrzypińska-Gawrysiak ◽  
ANNA KILANOWICZ
Keyword(s):  
Occupational Exposure ◽  
The Body ◽  
Exposure Level ◽  
Occupational Exposure Limits ◽  
Exposure Limits ◽  
Short Term ◽  
Cellulose Esters ◽  
Limit Values ◽  
Exposure Limit ◽  
Short Term Exposure

Nitroethane is a colorless oily liquid with a mild fruity odor. It is used mainly as a pro-pellant (e.g., fuel for rockets), and as a solvent or dissolvent agent for cellulose esters, resins (vinyl and alkyd) and waxes, and also in chemical synthesis.Occupational exposure to nitroethane may occur during the process of its production and processing. There are no data on air concentra-tions of nitroethane in occupational exposure. In 2010–2015, workers in Poland were not exposed to nitroethane concentrations exceed-ing the maximum allowable value – 75 mg/m3 (the limit value valid since 2010).Nitroethane can be absorbed into the body via inhalation of its vapors or by ingestion.The discussed cases of nitroethane acute poi-soning caused by an accidental ingestion of artificial fingernail remover containing pure nitroethane concerned children under three years. Few hours after ingestion, cyanosis and sporadic vomiting were observed in children. The methemoglobin level reached 40÷50%.Neither data on chronic nitroethane poisoning in humans nor data obtained from epidemio-logical studies are available.On the basis of the results of acute toxicity studies nitroethane has been categorized in the group of hazardous compounds. However, eye and dermal irritation or allergic effects have not been evidenced. The studies of sub-chronic (4 and 90 days) and chronic (2 years) exposure to nitroethane per-formed on rats and mice (concentration range 310 ÷ 12 400 mg/m3) revealed the methemo-globinogenic effect of this compound and a minor damage to liver, spleen, salivary gland and nasal turbinates.Niroethane has shown neither mutagenic nor carcinogenic effects. Its influence on fertility has not been evidenced either. After chronic exposure (2 years) of rats to ni-troethane at concentration of 525 mg/m3 (the lowest observed adverse effect level – LOAEL), a slight change in a body mass of exposed fe-male animals and subtle changes in biochemi-cal parameters were observed, but there were no anomalies in hematological and histopatho-logical examinations.The value of 62 mg/m3 has been suggested to be adopted as the MAC value for nitroethane after applying the LOAEL value of 525 mg/m3 and relevant coefficients of uncertainty. The STEL value for nitroethane was proposed ac-cording to the methodology for determining short term exposure level value for irritating substances as three times MAC value (186 mg/m3) to prevent the effects of sensory irri-tations in humans. Because of its methemoglo-binogenic effect, 2% Met-Hb has been suggest-ed to be adopted as the value of biological ex-posure index (BEI), like the value already adopted for all methemoglobinogenic sub-stances.The Scientific Committee on Occupational Exposure Limits (SCOEL) proposed the time-weighted average (TWA) for nitroethane (8 h) as 62 mg/m3 (20 ppm), short-term exposure limit (STEL, 15 min) as 312 mg/m3 (100 ppm) and “skin” notation.Proposed OEL and STEL values for nitroethane were subjected to public consultation, con-ducted in 2011 by contact points, during which Poland did not raise any objections to the pro-posals. The proposed values for nitroethane by SCOEL has been adopted by the Advisory Committee on Safety and Health at Work UE (ACSH) and included in the draft directive establishing the IV list of indicative occupa-tional exposure limit values.

4,4’- Isopropylidenediphenol – inhalable fraction. Documentation of proposed values of occupational exposure limits (OELs)

2018 ◽  
Vol 34 (4(98)) ◽  
pp. 5-40
Author(s):  
Jan Gromiec
Keyword(s):  
Occupational Exposure ◽  
Bisphenol A ◽  
Respiratory System ◽  
Mammalian Cells ◽  
Epoxy Resins ◽  
Exposure Limits ◽  
Exposure Limit ◽  
Short Term Exposure ◽  
Occupationally Exposed

4,4’- Isopropylidenediphenol (bisphenol A) is a white solid present in the form of crystals or flakes. It is used mostly in the production of epoxy resins (appr. 95% of its consumption). It is also used in the polycarbonate plastics, unsaturated polyester, polysulphonte and polyacrylate resins as well as flame retardants. Polycarbonate plastics are used to make products such as emulsions for thermal printers employed for printing tickets, labels, receipts, faxes etc. The routes of occupational exposure during production and application of bisphenol A are the respiratory system and the skin. The exact number of occupationally exposed to 4,4’- isopropylidenediphenol is not known but taking into account the wide use of polycarbonate and polyester resins it can be counted in thousands. Because of only trace amounts of bisphenol A in most of the resins, the levels of exposure are usually minimal. In Poland 4,4’- isopropylidenediphenol is used mainly as a component of glues for electronic parts, PVC stabilizer, addition components of epoxy resins and brake fluids. In 2010 only 4 persons were reported as occupationally exposed to bisphenol A dust in concentrations exceeding Polish OEL (5 mg/ m3) – 2 in the crop and animal production, hunting and related service activities sector and 2 in the water transport sector. In 2013 no workers exposed above OEL value were reported. Oral LD50 values beyond 2 000 mg/kg bw were found in the rat and mouse, and dermal LD50 values above 2 000 mg/kg are evident in the rabbit. 4,4’- Isopropylidenediphenol has been classified as Repr. 1.B, H360F (may damage fertility or the fetus) and substance that causes serious eye damage (H318) and may cause respiratory system irritation (H355). In workers having occupational contact with 4,4’- isopropylidenediphenol irritation of eyes, skin and respiratory system was observed. In animal experiments it was clearly shown that bisphenol A did not cause skin irritation, however, it was shown that the compound is an eye irritant. Slight and transient nasal tract epithelial damage was observed in rats exposed to bisphenol A dust which suggests that it appears to have a limited respiratory irritation potential. There are several reports of patients with dermatitis responding to BPA in patch tests, however, it is unclear whether bisphenol A or related epoxy resins were the underlying cause of the hypersensitive state. No reliable sensitisation animal data from experiments meeting the required standards are available. Toxicity of bisphenol A has been tested on mice, rats and dogs. The compound administered orally caused mainly a decrease in body weight gain; minor changes in organ weight, mostly in liver; respiratory disorders, diarrhea and death. From chronic experiments the liver and kidney seem to be the target organs. There are no in vivo data on mutagenic activity of bisphenol A. It also does not appear to produce either gene mutations or structural chromosome aberrations in bacteria, fungi or mammalian cells in vitro. The compound did not induce gene mutations in yeasts; sister chromatid exchange tests carried out on mammalian cells also gave negative effects. No information on human cancerogenicity of 4,4’- isopropylidenediphenol has been found in the literature and databases available. In a 103-week test on rats and mice of both sexes no convincing evidence indicating carcinogenic action of bisphenol A was found. Some studies indicate negative action of 4,4’- isopropylidenediphenol on reproduction which is a result of a mechanism of its action – in in vivo test the compound was found to bind to the nuclear estrogen receptors. However, data on the embryotoxic activity of bisphenol A and its effects on reproduction are not conclusive. Contradictory findings between the studies have been reported in several studies in rodents which was thoroughly discussed in the EFSA Report of 2015. In studies carried out in accordance with the FDA/NTCR standards 4,4’- isopropylidenediphenol effects on reproduction have been seen only at high doses showing also other toxic effects. Comprehensive tests with a wide range of doses did not confirm effects of 4,4’- isopropylidenediphenol on reproduction and development at low doses below 5 mg/kg bw. In Chinese epidemiological studies, impaired sperm quality in workers occupationally exposed to bisphenol A has been found, however, the effect of other concurrent exposures cannot be excluded. 4,4’- Isopropylidenediphenol in all species studied is conjugated with glucuronic acid and excreted as glucuronid with urine. The major route of excretion is via faeces; regardless of the route of entry 50-80% of the administered dose is eliminated with faeces in the unchanged form. In humans the compound is excreted as glucuronide or sulphate conjugates in urine. In Poland as well as in most other countries 5 mg/m3 as OEL and 10 mg/m3 as STEL have been established for 4,4’- isopropylidenediphenol. Scientific Committee on Occupational Exposure Limits (SCOEL) has proposed to establish an Indicative Occupational Exposure Limit (IOEL) in workplace air at the level of 2 mg/m3 taking the inhalation NOAEC of 10 mg/m3 from the rat study as a starting point for recommending an OEL. The critical effect in this study was respiratory tract irritation. According to SCOEL there is no toxicological basis for recommending an additional specific short-term exposure limit (STEL). Assignment of “skin” notation was also not recommended. The proposed OEL value for 4,4’- isopropylidenediphenol (inhalable fraction) has been derived from its irritating action on nasal tract epithelium in an inhalation study on experimental animals. The proposed OEL value is 2 mg/m3. This value should also protect workers against toxic effects on liver and kidney. There are no grounds for establishing a short-term exposure limit (STEL) nor for recommending a biological limit value (BLV). It is also proposed to introduce the following assignments: “I” – irritating substance and “A” – sensitizing substance.

The activity of the Interdepartmental Commission for Maximum Admissible Concentrations and Intensities for Agents Harmful to Health in the Working Environment in 2018 and the work plan in 2019

2019 ◽  
Vol 35 (1(99)) ◽  
pp. 77-87
Author(s):  
Danuta Koradecka ◽  
Jolanta Skowroń
Keyword(s):  
Occupational Exposure ◽  
Working Environment ◽  
Concentration Limit ◽  
Exposure Limits ◽  
Limit Values ◽  
Maximum Admissible Concentration ◽  
Exposure Limit ◽  
Copper Mines ◽  
Interdepartmental Commission

In 2018 the Commission met at three sessions, during which 9 documentations for recommended exposure limits of chemical substances, were discussed. Moreover the Commission discussed on: a system for notifying entrepreneurs, employees and inspection bodies of proposals for new or verified binding values (for carcinogenic and mutagenic substances) or indicator values for harmful chemicals in the form of messages, rules for setting limit values for harmful to health chemicals in the working environment, a program to improve working conditions in copper mines of KGHM Polska Miedź SA. and the methodology for determining hygiene standards for active substances of cytostatics, taking into account the uncertainty factor "F". The Commission suggested to the Minister of Family, Labour and Social Policy the following changes in the list of MAC values: adaptation of the Polish list of maximum admissible concentration (MAC-NDS) to Directive 2019/130/EC of 31/1/2019 amending Directive 2004/37/EC on the protection of workers from the risks related to exposure to carcinogens or mutagens at work (these are: chloroethene, o-toluidine and 1,3-butadiene), adjusting the MAC-value for trimethylamine to the value included in the draft directive setting the fifth list of indicative occupational exposure limits, introducing changes in the list of the maximum admissible concentration of chemicals and dust harmful to health for the substances mentioned, introduce the following substances into the list of maximum admissible concentrations of chemical agents harmful to health: phenolphthalein (Carc. 1B), etoposide (Carc. 1B), fluorouracil (Muta. 1B, skin), 2-nitroanisole (Carc. 1B), N-nitrosodimethylamine (Carc. 1B). Four issues of the "Principles and Methods of Assessing the Working Environment" were published in 2018. The booklets included: 11 documentation of occupational exposure limit, 11 methods for the determination of chemical concentrations in the working environment, 4 articles, a report on the activities of the Interdepartmental Commission for MACs and MAIs in 2017 and the indexes of the documentations, methods and articles published between 2000-2018. Three sessions of the Commission are planned for 2019. MAC values for 10 chemicals substances will be discussed at these meetings. The Commission and the Group of Experts will continue to work on adapting the Polish list of the maximum admissible concentrations to: proposals for binding values for carcinogenic or mutagenic substances, proposed concentration limit values developed by the Committee for Risk Assessment (RAC) and work carried out at SCOEL.

scholarly journals Exposure of workers to occupational heat during the application of phytosanitary products in coffee crop

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Lucas Deleon Ramirio ◽  
Paulo Henrique Siqueira Sabino ◽  
Geraldo Gomes de Oliveira Júnior ◽  
Adriano Bortolotti da Silva ◽  
Wilson Roberto Pereira
Keyword(s):  
Thermal Stress ◽  
Occupational Exposure ◽  
Thermal Shock ◽  
Tolerance Limit ◽  
Occupational Exposure Limit ◽  
Exposure Limits ◽  
Exposure Limit ◽  
Phytosanitary Products

During the application of phytosanitary products in coffee trees, workers may be exposed to temperatures that could compromise their health. Exposure to occupational heat can lead to progressive dehydration, cramps, exhaustion and the possibility of thermal shock. Thus, knowing the levels of occupational heat that workers are exposed becomes important. This study aimed to evaluate workers’ occupational exposure to heat during the application of phytosanitary products with manual costal pump in the coffee crops. The case study was developed at the IFSULDEMINAS school farm - Campus Inconfidentes in the months of September and October 2017. The occupational heat in the coffee crop was evaluated using the WBGTAVERAGE method, using TGD 400 thermal stress meter. The WBGT values found were compared to the exposure limits of NR 15 for the purposes of insalubrity classification and with NHO 06 for acclimatized and non-acclimatized workers. The results showed that the WBGT found is below the tolerance limit of NR 15, for the month of September. In October, the tolerance limit was exceeded in the period from 11:00 a.m. to 2:59 p.m., considering a continuous heavy activity and rest in the workplace, and the activity considered unhealthy. Considering the criteria of the NHO 06 it was observed that the limits of occupational exposure were exceeded in the month of October, for acclimatized and non-acclimatized workers. In September the occupational exposure limit of NHO 06 was exceeded only for non-acclimated workers. Therefore, the workers should be submitted to acclimatization during the phytosanitary application activity in the month of October.

The activity of the Interdepartmental Commission for Maximum Admissible Concentrations and Intensities for Agents Harmful to Health in the Working Environment in 2017 and the work plan in 2018

2018 ◽  
Vol 34 (1(95)) ◽  
pp. 111-129
Author(s):  
Danuta Koradecka ◽  
Jolanta Skowroń
Keyword(s):  
Social Policy ◽  
Occupational Exposure ◽  
Underground Mining ◽  
Working Environment ◽  
Occupational Exposure Limit ◽  
Exposure Limits ◽  
Limit Values ◽  
Chemical Substances ◽  
Exposure Limit ◽  
Interdepartmental Commission

In 2017, the Commission met at three sessions, in which 16 documentations for recommended exposure limits of chemical substances were discussed. Moreover, the Commission discussed: − the positions of the Interdepartmental Commission for MAC and MAI regarding: smog, limit value of nitric oxide in the underground mining and tunnels sector and binding value for 1,2-dichloroethane − introduction of the "skin" notation (substances absorption through the skin may be important as in the case of inhalation) for chemical substances included in the regulation of the Minister of Labour and Social Policy of 6 June 2014. The Commission suggested to the Minister of Family, Labour and Social Policy the following changes in the list of MAC values: − adding five new chemical substances to the list of MAC values: qinoline (CAS: 91-22-5, Carc. 1B, skin), cisplatin (CAS: 15663-27-1, Carc. 1B, skin), N-hydroxyurea (CAS: 127-07-1, Carc. 1B), potassium bromate (CAS: 7758-01-2, Carc. 1B, skin) oraz 3,3’-dimethylbenzidene (CAS: 119-903-7) and salts: 3,3’ dimethylbenzidene dihydrochloride (CAS: 612-82-2, Carc. 1B) − changing MAC values for 10 chemicals: bis-phenol A (CAS: 80-05-7), acrylic acid (CAS: 79-10-7, skin), nitrogen oxide (CAS: 10102-43-9 ), dichloromethane (CAS: 75-09-2, skin), 1,1-dichloroethylene (CAS: 75-35-4), hydrogenated terphenyls (CAS: 61788-32-7), 2-nitropropane (CAS: 79-46-9, skin), 1,2-epoxypropane (CAS: 75-56-9), 1,2-dichloroethane (CAS: 107-06-2, skin), phenylhydrazine (CAS: 100-63-0, skin) as phenylhydrazine) and its salts: phenylhydrazine hydrochloride (CAS: 59-88-1; 27140-08-5, skin), phenylhydrazine sulphate (CAS: 52033-74-6, skin) − adding to Annex 1 the "skin" notation (substances absorption through the skin may be important as in the case of inhalation) for chemical substances included in the regulation of the Minister of Labour and Social Policy (Journal of Laws of 2014, item 817 with amended). The Interdepartmental Commission for MAC and MAI adopted the MAC value for inhalable fraction of urea at the level of 10 mg/m3 as the value recommended for manufacturers and plants. The documentation of the proposed occupational exposure limit values for urea with the recommended value of 10 mg/m3 and with the method of determining it concentrations in the working environment will be published in "Principles and Methods of Assessing the Working Environment". Four issues of the "Principles and Methods of Assessing the Working Environment " were published in 2017. The following were published: 12 documentation of occupational exposure limit, 12 methods of determining chemical concentrations in the working environment, two articles, a procedure for measuring electromagnetic field, a report on the activities of the Interdepartmental Commission for MACs and MAIs in 2017 and indexes of documentations, methods and articles published between 2000–2017. Three sessions of the Commission are planned for 2018. MAC values for 15 chemicals substances will be discussed at those meetings. The Commission and the Group of Experts will continue working on adapting the Polish list of maximum admissible concentrations to proposals for binding values for carcinogenic or mutagenic substances, proposed concentration limit values developed by the Committee for Risk Assessment (RAC) and on work being done at SCOEL.

scholarly journals A Case Study of Brass Foundry Workers’ Estimated Lead (Pb) Body Burden from Different Exposure Routes

2020 ◽  
Vol 64 (9) ◽  
pp. 970-981
Author(s):  
Anneli Julander ◽  
Klara Midander ◽  
Sandra Garcia-Garcia ◽  
Per Vihlborg ◽  
Pål Graff
Keyword(s):  
Occupational Exposure ◽  
Numerical Control ◽  
Skin Absorption ◽  
Exposure Limits ◽  
Limit Values ◽  
Skin Exposure ◽  
Diffusion Cells ◽  
Exposure Limit ◽  
Exposure Routes

Abstract Objectives The most pronounced occupational exposure routes for lead (Pb) are inhalation and gastrointestinal uptake mainly through hand-to-mouth behaviour. Skin absorption has been demonstrated for organic Pb compounds, but less is known about inorganic Pb species. Several legislative bodies in Europe are currently proposing lowering biological exposure limit values and air exposure limits due to new evidence on cardiovascular effects at very low blood Pb levels. In light of this, all exposure routes in occupational settings should be revisited to evaluate how to lower the overall exposure to Pb. Methods The aim of the study was to investigate the possible exposure routes in workers operating computer numerical control-machines in a brass foundry and specifically to understand if metal cutting fluids (MCFs) used by the workers could lead to skin absorption of Pb. The different bronze alloys at the facility may contain up to 20% Pb. After obtaining written informed consent from the workers (n = 7), blood, skin wipes, and personal air samples were collected. In addition, MCFs used on the day of exposure measurements were collected for in vitro skin absorption studies using stillborn piglet skin mounted in static Franz diffusion cells (n = 48). All samples were analysed for Pb content using inductively coupled plasma mass spectrometry. Results Pb air concentration (<0.1–3.4 µg m−3) was well below the Swedish occupational exposure limit value. Blood Pb was in the range of <0.72–33 µg dl−1, and Pb on skin surfaces, after performing normal work tasks during 2 h, was in the range of 0.2–48 µg cm−2. Using the MCFs in diffusion cells showed that skin absorption had occurred at very low doses, and that up to 10% of the Pb content was present in the skin after 24 h exposure. Using these results in the US EPA adult lead model, we could estimate a contribution to blood Pb from the three exposure routes; where hand-to-mouth behaviour yielded the highest contribution (16 µg Pb dl−1 blood), followed by skin absorption (3.3–6.3 µg Pb dl−1 blood) and inhalation (2.0 µg Pb dl−1 blood). Conclusions This case study shows that MCF may lead to skin absorption of inorganic Pb and contribute to a systemic dose (quasi-steady state). Furthermore, even though good hand hygienic measures were in place, the workers’ skin exposure to Pb is in all likelihood an important contributor in elevating blood Pb levels. Skin exposure should thus be monitored routinely in workers at facilities handling Pb, to help reducing unnecessary occupational exposure.

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