Introduction<\/p>\n
This module examines the work of the hygienist in terms of evaluating the environment (monitoring).\u00a0\u00a0 The principles behind the development of occupational exposure limits and the legislation regarding OELs and hygiene monitoring will be reviewed.\u00a0 Other topics include hygiene sampling techniques and equipment, addressing the categories and applications of major monitoring and analytical instruments that are used.\u00a0 It will also identify the relevance of calibration of equipment in conducting hygiene sampling.\u00a0 Contents of what constitutes a good hygiene report are also addressed.<\/p>\n
Learning Outcome<\/p>\n
By the completion of module 1, the student will have knowledge about:<\/p>\n
The principles behind evaluating worker exposure from an industrial hygiene perspective.<\/p>\n
The principles behind occupational exposure limits (e.g. TLVs, TWAs, TWAEVs, STELs, PELs, CELs etc) \u2013 usefulness and limitations.<\/p>\n
Calculate time-weighted averages<\/p>\n
The legislation as it applies to occupational hygiene under the OH&S Act.<\/p>\n
Where to find current Ontario Occupational Exposure Limits and how to interpret them.<\/p>\n
The purpose and scope of exposure measurement.<\/p>\n
Types of monitoring: personal, environmental, biological and medical\/health.<\/p>\n
What a sampling strategy is.\u00a0 What you need to take into consideration when developing a sampling strategy\u00a0<\/p>\n
Categories and applications of major monitoring and analytical instruments used for evaluation of the occupational environment.<\/p>\n
Importance of Calibration, accuracy, precision<\/p>\n
Components of hygiene reports<\/p>\n
Checklist for critiquing a hygiene report<\/p>\n
Content<\/p>\n
Occupational Exposure Limits (OELs) restrict the amount and length of time a worker is exposed to airborne concentrations of hazardous biological or chemical agents.<\/p>\n
There are\u00a0OELs for over\u00a0725 substances\u00a0under R.R.O. 1990, Regulation 833 (Control of Exposure to Biological or Chemical Agents) and Ontario Regulation 490\/09 (Designated Substances) under Ontario\u2019s Occupational Health and Safety Act.\u00a0<\/p>\n
In 2004, the Ministry of Labour introduced a review process for\u00a0OELs to ensure that these limits are regularly reviewed and updated. Under this process, the\u00a0MOL\u00a0releases for public consultation proposals for new or revised\u00a0OELs based on the annual recommendations of the American Conference of Governmental Industrial Hygienists (ACGIH). During consultations, stakeholders are invited to submit comments on any or all of the proposed changes.\u00a0https:\/\/www.labour.gov.on.ca\/english\/hs\/topics\/oels.php<\/p>\n
Employers are required under section 4 of Regulation 833, Control of Exposure to Biological or Chemical Agents (the \u201cRegulation\u201d), to limit the exposure of workers to specified hazardous biological or chemical agents in accordance with the values set out in the \u201cOntario Table\u201d (which is Table 1 in the Regulation) or, if the agent is not listed in the Ontario Table, the 2015\u00a0ACGIH\u00a0Table that is incorporated by reference in the Regulation.<\/p>\n
For ease of reference, the following table contains\u00a0all\u00a0specific occupational exposure limits an employer must implement under s. 4 of the Regulation,\u00a0i.e.\u00a0it sets out information found in both the Ontario Table in Regulation 833 and the\u00a0ACGIH\u00a0Table.\u00a0<\/p>\n
In addition, the table includes listings (i.e.\u00a0Petroleum ether, Rubber solvent and VM&P Naphtha) not included in either the Ontario Table or the\u00a0ACGIH\u00a0Table. The Ministry recommends that\u00a0OELs for those substances be calculated using the recommended method referenced.<\/p>\n
An employer has a duty and shall take all measures reasonably necessary in the circumstances to protect workers from exposure to a hazardous biological or chemical agent.\u00a0<\/p>\n
This table should not be solely relied upon to determine the exposure limits for substances. In order to determine all exposure limits, including excursion limits for a substance, please refer to the official version of the Regulation. \u00a0https:\/\/www.labour.gov.on.ca\/english\/hs\/pubs\/oel_table.php<\/p>\n
ACGIH defines three categories of threshold limit values:<\/p>\n
Threshold Limit Value \u2013 Time-Weighted Average (TLV-TWA):\u00a0The concentration of a hazardous substance in the air averaged over an 8-hour workday and a 40-hour workweek to which it is believed that workers may be repeatedly exposed, day after day, for a working lifetime without adverse effects.<\/p>\n
Threshold Limit Value \u2013 Short-term exposure (TLV-STEL):\u00a0A 15-minute time weighted average exposure that should not be exceeded at any time during a workday, even if the overall 8-hour TLV-TWA is below the TLV-TWA. Workers should not be exposed more than four times per day to concentrations between TLV-TWA and TLV-STEL. There should be at least a 60 minute interval between exposures. The short-term exposure threshold has been adopted to account for the acute effects of substances that have primarily chronic affects.<\/p>\n
Threshold Limit Value \u2013 Ceiling\u00a0(TLV-C): This is the concentration that should not be exceeded during any part of the working exposure. Peak exposures should be always controlled. For substances that do not have TLV-TWA or TLV-C established, the maximum admissible peak concentrations must not exceed:<\/p>\n
Three-times the value of the TLV-TWA for no more than 15 minutes, no more than four times per workday. Exposures must be at least 1 hour apart during the workday.<\/p>\n
Five times the TLV-TWA under any circumstances.<\/p>\n
The units of measures for the threshold limit values are ppm and mg\/m3. The TLVs for aerosols are expressed usually in mg\/m3. The TLVs for gases and vapours are expressed in ppm or mg\/m3. \u00a0https:\/\/www.ccohs.ca\/oshanswers\/hsprograms\/occ_hygiene\/occ_exposure_limits.html<\/p>\n
In the workplace, a worker may be exposed to several chemical substances at a time. If the toxicological effect of the substances is similar (e.g., each substance affects same target organ or has a similar effect), it can be considered that the combined effect of the chemicals will be the sum of individual effects. A common example is exposure to several organic solvents.<\/p>\n
In this case, ACGIH recommends the following calculation:<\/p>\n
If the sum of:<\/p>\n
C1\/T1 + C2\/T2 +\u2026.Cn\/Tn\u00a0<\/p>\n
is higher than 1, the threshold limit of the mixture is exceeded.<\/p>\n
(C is the concentration in the air of the substance and T is the threshold limit)<\/p>\n
This formula should not be used for:<\/p>\n
mixtures of substances with toxicological effects are not additive (individual toxicological effects and target organs are different),<\/p>\n
mixtures of substances which inhibit each other\u2019s effect,<\/p>\n
substances that may have a synergistic effect,<\/p>\n
carcinogens (exposure to mixtures of carcinogens should\u00a0be eliminated or as low as possible), and\u00a0<\/p>\n
complex mixtures (e.g., diesel exhaust).<\/p>\n
https:\/\/www.ccohs.ca\/oshanswers\/hsprograms\/occ_hygiene\/occ_exposure_limits.html<\/p>\n
The threshold limit values apply for 8-hour workday and 40-hour workweek. When working shifts longer than eight hours, the exposure time is increased and the recovery period between exposures is decreased. In these situations, the threshold exposure limit should be so adjusted that in the end the peak body burden does not exceed the one that would occur during a normal eight hour shift.<\/p>\n
There are numerous mathematical models, some simple and some more complex, that can be used to adjust the TLV to a different work schedule. The Brief and Scala model is recommended by ACGIH as a simpler model which reduces the TLV by a factor that takes into account the hours worked daily and the periods of rest between them.<\/p>\n
The number of days worked per week is not considered, except for a 7-day-workweek (e.g. for a 56 workdays followed by 21 days off schedule). The formula to be applied for a 7-day workweek is:<\/p>\n
For example, the modified TLV-TWA for toluene (TLV-TWA = 20 ppm) for a 12-hr\/day 14-day pattern shift (five workdays one week and two workdays the next week) will be:<\/p>\n
(The reduction factor is calculated for the 12-hour workday regardless of how many days, 5 or 2, are worked during a week).<\/p>\n
One of the shortcomings of the Brief and Scala method is that the reduction factor for a certain amount of worked hours is identical for all chemicals regardless of their individual biological half-lives. This assumption may lead to an overestimation of the degree to which the limit should be lowered.<\/p>\n
The formula is not applicable for:\u00a0<\/p>\n
Work schedules with less than seven to eight hours per day or less than 40 hours per week.<\/p>\n
Work schedules that involve 24-hour continuous exposure (e.g., in submarines and space shuttles).<\/p>\n
Certain irritants.<\/p>\n
https:\/\/www.ccohs.ca\/oshanswers\/hsprograms\/occ_hygiene\/occ_exposure_limits.html<\/p>\n
Particle Size-Selective sampling criteria for airborne particulate matter
The Particle Size-Selective TLVs\u00ae (PSS-TLVs) are expressed in three forms:<\/p>\n
Inhalable Particulate Matter TLVs\u00ae (IPM-TLVs) for those materials that are hazardous when deposited anywhere in the respiratory tract.<\/p>\n
Thoracic Particulate Matter TLVs\u00ae (TPM-TLVs) for those materials that are hazardous when deposited anywhere within the lung airways and the gas-exchange region.<\/p>\n
Respirable Particulate Matter TLVs\u00ae (RPM-TLVs) for those materials that are hazardous when deposited in the gas-exchange regionFootnote\u00a04.<\/p>\n
Particles (insoluble or poorly soluble) not otherwise specified (PNOS)
Particles that: Do not have an applicable TLV; are insoluble or poorly soluble in water (or, preferably, in aqueous lung fluid if data are available); and have low toxicity (i.e., are not cytotoxic, genotoxic, or otherwise chemically reactive with lung tissue, and do not emit ionizing radiation, cause immune sensitization, or cause toxic effects other than by inflammation or the mechanisms of \u201clung overload\u201d)Footnote\u00a04.<\/p>\n
ACGIH\u00ae believes that even biologically inert, insoluble, or poorly soluble particles may have adverse effects and recommends that airborne concentrations should be kept below 3 mg\/m3, respirable particles; and 10 mg\/m3, inhalable particles, until such time as a TLV\u00ae is set for a particular substanceFootnote\u00a04.<\/p>\n
Part per million (ppm)
A measure of concentration of a vapour or gas in air. It is a volume per volume unit. The unit ppm is an abbreviation of the term part per millionFootnote\u00a03.<\/p>\n
Respiratory sensitization notation (RSEN)
Warns of an agent to produce respiratory sensitizationFootnote\u00a04.<\/p>\n
Skin notation (Skin)
The designation \u201cSkin\u201d in the \u201cNotations\u201d column refers to the potential significant contribution to the overall exposure by the cutaneous route, including mucous membranes and the eyes, by contact with vapors, liquids, and solidsFootnote\u00a04.<\/p>\n
Threshold limit value\u2013Ceiling (TLV-C)
The concentration that should not be exceeded during any part of the working exposure. If instantaneous measurements are not available, sampling should be conducted for the minimum period of time sufficient to detect exposures at or above the ceiling valueFootnote\u00a04.<\/p>\n
Threshold limit value-Short-term exposure limit (TLV-STEL)
A 15-minute TWA exposure that should not be exceeded at any time during a workday, even if the 8-hour TWA is within the TLV-TWA. The TLV-STEL is the concentration to which it is believed that workers can be exposed continuously for a short period of time without suffering from 1) irritation, 2) chronic or irreversible tissue damage, 3) dose-rate-dependent toxic effects, or 4) narcosis of sufficient degree to increase the likelihood of accidental injury, impaired self-rescue, or materially reduced work efficiency. The TLV-STEL will not necessarily protect against these effects if the daily TLV-TWA is exceededFootnote\u00a04.<\/p>\n
Threshold limit value-Time-weighted average (TLV-TWA)
The TWA concentration for a conventional 8-hour workday and 40-hour workweek, to which it is believed that nearly all workers may be repeatedly exposed, day after day, for a working lifetime without adverse effectFootnote\u00a04.<\/p>\n
Threshold limit values (TLVs\u00ae)
A threshold limit value refers to an airborne concentration of a chemical substance and represents conditions under which it is believed that nearly all workers may be repeatedly exposed, day after day, over a working lifetime, without adverse health effects. It is a health-based value. TLVs are determined at normal temperature and pressure (NTP). Note: A correction factor shall be applied to sampled values taken at work place conditions that differ from NTP. Refer to the ACGIH publication, Threshold Limit Values and Biological Exposure IndicesFootnote\u00a04.<\/p>\n
Upper confidence limit (UCL)
The UCL should be calculated when many measurements are taken at a work place for the purpose of an industrial hygiene monitoring program as part of the internal responsibility system. If a measured sampling value is less than, but close to its respective TLV or OEL, then the UCL should be calculated. If the UCL added to the measured sampling value is still less than the TLV or OEL, then there is compliance. Refer to the NIOSH publication, Occupational Exposure Sampling Strategy Manual for UCL formulas and example calculationsFootnote\u00a06.<\/p>\n
https:\/\/www.canada.ca\/en\/employment-social-development\/services\/health-safety\/reports\/hazardous-substances-sampling-guideline.html<\/p>\n
Airborne contaminants can present a significant threat to worker health and safety. Thus, identification and quantification of these contaminants through air monitoring is an essential component of a health and safety program at a hazardous waste site. Reliable measurements of airborne contaminants are useful for:<\/p>\n
Selecting personal protective equipment.<\/p>\n
Delineating areas where protection is needed.<\/p>\n
Assessing the potential health effects of exposure<\/p>\n
Determining the need for specific medical monitoring. This chapter delineates the factors to<\/p>\n
consider when conducting air monitoring at a hazardous waste site. It presents strategies for assessing airborne contamination at hazardous waste sites and describes instruments and methods for measuring exposures.<\/p>\n
Measuring Instruments<\/p>\n
The purpose of air monitoring is to identify and quantify airborne contaminants in order to determine the level of worker protection needed. Initial screening for identification is often qualitative, i.e., the contaminant, or the class to which it belongs, is demonstrated to be present but the determination of its concentration (quantification) must await subsequent testing. Two principal approaches are available for identifying and\/or quantifying airborne contaminants:<\/p>\n
The onsite use of direct-reading instruments.<\/p>\n
Laboratory analysis of air samples obtained by gas sampling beg, filter, sorbent, or wet- contaminant collection methods.<\/p>\n
https:\/\/www.osha.gov\/Publications\/complinks\/OSHG-HazWaste\/7-8.pdf<\/p>\n
Monitoring and surveillance activities under Canada’s Chemicals Management Plan<\/p>\n
Background<\/p>\n
On December 8, 2006 the Government of Canada launched the Chemicals Management Plan (CMP). The Plan acts to safeguard human health and the environment of Canadians and includes a number of proactive measures to ensure that chemical substances are managed properly.<\/p>\n
A key element of the Chemicals Management Plan is the monitoring and surveillance of levels of harmful chemicals in Canadians and their environment. Monitoring and surveillance are essential to identify and track exposure to hazards in the environment and associated health implications. Monitoring and surveillance programs provide the basis for making sound and effective public health and environmental health policies and interventions, as well as measuring the efficacy of control measures.<\/p>\n
In support of the Chemicals Management Plan, monitoring and surveillance initiatives were established to support Health Canada and Environment Canada scientists, in collaboration with external partners and researchers, to advance our knowledge. This initiative has allowed the Government of Canada to increase its commitment to a number of existing monitoring initiatives, as well as to support new efforts.<\/p>\n
Environmental monitoring<\/p>\n
Monitoring and surveillance involves the regular collection of physical, chemical and biological data using standard methods and protocols to detect and characterize environmental change. Environment Canada’s national CMP Environmental Monitoring and Surveillance Program focuses on monitoring of chemicals in multiple environmental media: air, water, sediment, non-human biota (fish and wildlife); as well as source monitoring (wastewater treatment plant effluents and sludge; landfill leachate and biogas). This program builds on Canada’s existing environmental monitoring programs and complements the human health biomonitoring conducted by Health Canada. Together these programs generate science-based information essential to identifying risks and informing risk assessment and risk management, and support informed decision-making. See also\u00a0Environmental Monitoring and Surveillance in Support of the Chemicals Management Plan.<\/p>\n
Environmental monitoring data has a variety of uses including:<\/p>\n
Quantifying exposure levels and generating science-based information necessary to identify risks and inform risk management<\/p>\n
Understanding environmental fate and behaviour of chemicals<\/p>\n
Evaluating performance of control actions<\/p>\n
Environmental Monitoring and Surveillance Initiatives include:<\/p>\n
National monitoring program for measuring ambient environmental concentrations of CMP priority substances in: wildlife, fish, air, sediment and water.<\/p>\n
As many of the emerging contaminants of concern are found in products which routinely end up in landfill or wastewater at end-of-life, under the CMP, a national monitoring program is being set up to characterize trends of priority compounds in wastewater, and assess the effectiveness of treatment systems at removing these compounds from final effluent and treated biosolids.<\/p>\n
A comprehensive cross-country landfill monitoring program will be piloted in order to provide information on the current state of release to the Canadian environment of priority compounds from landfill leachate, landfill gas and incineration.<\/p>\n
Human Biomonitoring<\/p>\n
Human exposure to chemicals is an important area of focus for the Government. Human biomonitoring is the measurement of a chemical and its by-products in people. These measurements are usually taken in blood and urine and sometimes in other tissues and fluids such as hair, nails, and breast milk. The measurements indicate how much of a chemical is present in that person.<\/p>\n
Human biomonitoring data has a variety of uses including:<\/p>\n
Establishing baseline levels of chemicals in Canadians and detecting trends in exposure over time and by geographical region;<\/p>\n
Identifying populations that might have higher levels of specific substances, and who may be at higher risk of adverse health effects;<\/p>\n
Examining the relationship between the amount of exposure (i.e. the dose) and health effects;<\/p>\n
Identifying substances that were not previously thought to be a concern or to accumulate in people;<\/p>\n
Setting priorities and taking action to protect the public’s health;<\/p>\n
Assessing the effectiveness of public health and environmental actions intended to reduce exposures and health risks of Canadians to specific chemicals;<\/p>\n
Helping to focus future research efforts on the links between exposure and health.<\/p>\n
Monitoring and Surveillance Initiatives: \u00a0Health Canada’s monitoring and surveillance initiatives are categorized in four broad themes:<\/p>\n
National Biomonitoring Initiatives<\/p>\n
Initiatives in this area conduct biomonitoring on a national scale.\u00a0<\/p>\n
Canadian Health Measures Survey<\/p>\n
Maternal-Infant Research on Environmental Chemicals<\/p>\n
Northern Contaminants Program (multi-partner, multi-year initiatives)<\/p>\n
First Nations Biomonitoring Initiative (consultation phase)<\/p>\n
Targeted Population Biomonitoring Initiatives<\/p>\n
Initiatives in this area conduct biomonitoring or exposure studies targeting sub-populations of interest.\u00a0<\/p>\n
A pilot study to assess the feasibility of measuring chronic exposure to lead among Canadians<\/p>\n
Canadian study of the impact of residential sources of lead on blood lead levels of young children<\/p>\n
Biomonitoring for environmental lead exposure in children from pre-1970s housing in St. John’s, Newfoundland and Labrador<\/p>\n
The P4 study: Plastics and personal care product use in pregnancy<\/p>\n
Biological monitoring of exposure to inorganic arsenic in a population in the Abitibi-T\u00e9miscamingue region using drinking water from private wells<\/p>\n
Biomonitoring of arsenic species in rural Nova Scotia communities<\/p>\n
Assessment of long-term indoor residential pollution exposures among Canadian children<\/p>\n
Importance of exposure to acrylamide in a potentially vulnerable population through consumption of acrylamide rich food<\/p>\n
Biomonitoring Supportive Research<\/p>\n
Initiatives in this area conduct research to advance biomonitoring scientific methods and techniques and to develop tools to better understand, interpret, and communicate biomonitoring results.\u00a0<\/p>\n
Development of biomonitoring equivalents and use of physiologically based pharmacokinetic models for interpreting Canadian biomonitoring data<\/p>\n
Toxicokinetic modelling of pyrethroids for dose reconstruction in the Canadian population<\/p>\n
Identification of biomarkers of environmental contaminant toxicity through analysis of MIREC samples<\/p>\n
Dermal absorption of substances being assessed under the Chemicals Management Plan<\/p>\n
Analytical tools for health and environmental biomonitoring of manufactured nanomaterials in chemical substances and Food and Drugs Act substances<\/p>\n
Study of metabolomic and transcriptomic responses with high and low exposures to brominated flame retardants<\/p>\n
Targeted Environmental Monitoring to Support the Chemicals Management Plan<\/p>\n
Initiatives in this area conduct monitoring of chemical substances in various environmental media to better assess human exposures in support of risk management under the\u00a0Canadian Environmental Protection Act, 1999.\u00a0<\/p>\n
Metal speciation and pesticides in Canadian house dust samples<\/p>\n
National indoor air survey of chemicals under the\u00a0Canadian Environmental Protection Act, 1999\u00a0and the Chemicals Management Plan<\/p>\n
National survey of disinfection by-products and selected contaminants in Canadian drinking water<\/p>\n
Dietary exposure of young children to emerging persistent organic pollutants and plasticizers<\/p>\n
Human exposure assessment of perfluorinated compounds in fish caught near possible major industrial sources, and effects of skin removal and cooking on exposure<\/p>\n
https:\/\/www.canada.ca\/en\/health-canada\/services\/chemical-substances\/chemicals-management-plan\/monitoring-surveillance.html<\/p>\n
Readings\/ Resources<\/p>\n
Rekus, J. (2003). Yes, Even you can do Industrial Hygiene Air Sampling.\u00a0EHS Today.\u00a0 Introduction to Air Sampling
http:\/\/ehstoday.com\/industrial_hygiene\/instrumentation\/ehs_imp_36372<\/p>\n
\u00a0SKC Guide to OSHA\/NIOSH\/ASTM Air Sampling Methods\u00a0http:\/\/www.skcinc.com\/catalog\/osha-niosh.php<\/p>\n
American Conference of Governmental Industrial Hygienists\u00a0Threshold Limit Values and Biological Exposure Indices,\u00a0ACGIH: Cincinnati.\u00a0 Section on \u201cintroduction to chemical substances\u201d.\u00a0<\/p>\n
http:\/\/www.acgih.org\/tlv-bei-guidelines\/tlv-chemical-substances-introduction<\/p>\n
Personal Sampling in the workplace:\u00a0http:\/\/www.afcintl.com\/pdfs\/Morphixpdf\/kmarticle.pdf<\/p>\n
Rekus, J. (2003). \u00a0 Yes, Even you Can Do Industrial Hygiene Air Sampling Part II.\u00a0 EHS Today.\u00a0 – personal sampling pumps\u00a0http:\/\/ehstoday.com\/industrial_hygiene\/instrumentation\/ehs_imp_36447<\/p>\n
Donahue, K. (1999). Smart Sampling. EHS Today\u00a0http:\/\/ehstoday.com\/industrial_hygiene\/instrumentation\/ehs_imp_32587<\/p>\n
\u00a0Rekus, J. (2003). Yes, Even You Can Do Industrial Hygiene Air Sampling Part III.\u00a0 EHS Today.\u00a0 – testing in the field<\/p>\n
http:\/\/ehstoday.com\/industrial_hygiene\/instrumentation\/ehs_imp_36496<\/p>\n
Learning Activities\/ Discussion Questions<\/p>\n
\u00a0Describe the following types of monitoring and any experience you have with the monitoring
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Personal<\/p>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Environmental\u00a0<\/p>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Biological<\/p>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Medical\/health<\/p>\n
\u00a0Consult the OH&S Act and identify what legislation applies to occupational hygiene.<\/p>\n
\u00a0Go to Ontario e-laws.\u00a0 Can you find where the current OELs (Occupational Exposure Limits) are located?\u00a0 (Hint, they are part of the Occupational Health and Safety Act.\u00a0 You will cover this in detail in the legislation course. \u00a0 What are designated substances and what relevance do they have for medical surveillance?<\/p>\n
What is a sampling strategy?\u00a0 (Why? What? Who? When? Where? How? How many? How Long?) What are all of the things which a hygienist has to consider in order determining this?<\/p>\n
\u00a0Hygienists spend a lot of time on calibrating equipment. \u00a0Why is this so important?<\/p>\n
\u00a0Explore the Internet and find examples of industrial hygiene sampling equipment.\u00a0\u00a0\u00a0 See if they specifically tell you what substances they can be used for and for which sampling technique.<\/p>\n
\u00a0Practice: \u00a0calculate time-weighted averages. Here is a practice example \u2013\u00a0Air sampling for lead was done and the results are as follows:\u00a0 3 hrs sampling = 0.004 mg\/m3 ;\u00a0\u00a02 hours = 0.002; 2 hrs = 0.005; 1 hour =0.05.\u00a0 What is the time weighted average?\u00a0 Is it below the 8 hour TLV (TWAEV)?\u00a0 Is this safe?<\/p>\n
\u00a0If you have access to an industrial hygienist or have the opportunity to interact with one, ask him\/her to show you the equipment and explain its use to you.\u00a0 If you are a joint health and safety committee member, ask if you can see copies of any industrial hygiene reports that they may have on file.\u00a0 If neither of the above are options, find samples of this equipment on the Internet and explore each one\u2019s purpose and how they would be used.<\/p>\n
What is the difference between health\/medical surveillance and hygiene surveillance?<\/p>\n","protected":false},"excerpt":{"rendered":"
Introduction This module examines the work of the hygienist in terms of evaluating the environment (monitoring).\u00a0\u00a0 The principles behind the development of occupational exposure limits and the legislation regarding OELs and hygiene monitoring will be reviewed.\u00a0 Other topics include hygiene sampling techniques and equipment, addressing the categories and applications of major monitoring and analytical instruments […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[10],"class_list":["post-106664","post","type-post","status-publish","format-standard","hentry","category-research-paper-writing","tag-writing"],"_links":{"self":[{"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/posts\/106664","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/comments?post=106664"}],"version-history":[{"count":0,"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/posts\/106664\/revisions"}],"wp:attachment":[{"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/media?parent=106664"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/categories?post=106664"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/tags?post=106664"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}