Air samplers are designed to meet differing measurement requirements. Some samplers are better suited for one form of measurement than others. Newer analytical techniques for assaying air samples include PCR methods and enzyme-linked immunosorbent assays ELISAs.

A detailed discussion of the principles and practices of water sampling has been published. Routine testing of the water in a health-care facility is usually not indicated, but sampling in support of outbreak investigations can help determine appropriate infection-control measures.

Water-quality assessments in dialysis settings have been discussed in this guideline see Water, Dialysis Water Quality and Dialysate, and Appendix C. Health-care facilities that conduct water sampling should have their samples assayed in a laboratory that uses established methods and quality-assurance protocols.

Consequently, water samples should be sent to the testing laboratory cold i. If the water contains elevated levels of heavy metals, then a chelating agent should be added to the specimen. The minimum volume of water to be collected should be sufficient to complete any and all assays indicated; mL is considered a suitable minimum volume.

Sterile collection equipment should always be used. Sampling from a tap requires flushing of the water line before sample collection. If the tap is a mixing faucet, attachments e. Such situations lead to false-negative readings and misleading assessments of water quality.

Appropriate neutralization of halogens and chelation of heavy metals are crucial to the recovery of these organisms. The choice of recovery media and incubation conditions will also affect the assay.

Incubation temperatures should be closer to the ambient temperature of the water rather than at Reduced nutrient media e. Use of aerobic, heterotrophic plate counts allows both a qualitative and quantitative measurement for water quality.

If bacterial counts in water are expected to be high in number e. The sample is filtered through the membrane, and the filter is applied directly face-up onto the surface of the agar plate and incubated.

Unlike the testing of potable water supplies for coliforms which uses standardized test and specimen collection parameters and conditions , water sampling to support epidemiologic investigations of disease outbreaks may be subjected to modifications dictated by the circumstances present in the facility.

Assay methods for waterborne pathogens may also not be standardized. Therefore, control or comparison samples should be included in the experimental design. Any departure from a standard method should be fully documented and should be considered when interpreting results and developing strategies.

Assay methods specific for clinically significant waterborne pathogens e. are more complicated and costly compared with both methods used to detect coliforms and other standard indicators of water quality. Routine environmental-surface sampling e. Surface sampling is used currently for research, as part of an epidemiologic investigation, or as part of a comprehensive approach for specific quality assurance purposes.

As a research tool, surface sampling has been used to determine. Some or all of these approaches can also be used during outbreak investigations.

Meaningful results depend on the selection of appropriate sampling and assay techniques. For quantitative assessment of surface organisms, non-selective, nutrient-rich agar media and broth e.

Broth media are used with membrane-filtration techniques. Further sample work-up may require the use of selective media for the isolation and enumeration of specific groups of microorganisms. Examples of selective media are MacConkey agar MAC [selects for gram-negative bacteria] , Cetrimide agar selects for Pseudomonas aeruginosa , or Sabouraud dextrose- and malt extract agars and broths select for fungi.

Qualitative determinations of organisms from surfaces require only the use of selective or non-selective broth media. Effective sampling of surfaces requires moisture, either already present on the surface to be sampled or via moistened swabs, sponges, wipes, agar surfaces, or membrane filters.

If disinfectant residuals are expected on surfaces being sampled, specific neutralizer chemicals should be used in both the growth media and the dilution or rinse fluids.

Lists of the neutralizers, the target disinfectant active ingredients, and the use concentrations have been published. The inclusion of appropriate control specimens should be included to rule out both residual antimicrobial activity from surface disinfectants and potential toxicity caused by the presence of neutralizer chemicals carried over into the assay system.

A concentration ranging from 0. Foaming may occur during use. Several methods can be used for collecting environmental surface samples Table Specific step-bystep discussions of each of the methods have been published.

However, these sampling methods are the most prone to errors caused by manipulation of the swab, gauze pad, or sponge. Thorough mixing of the rinse fluids after elution e. If sampling is conducted as part of an epidemiologic investigation of a disease outbreak, identification of isolates to species level is mandatory, and characterization beyond the species level is preferred.

Environmental surfaces should be visibly clean; recognized pathogens in numbers sufficient to result in secondary transfer to other animate or inanimate surfaces should be absent from the surface being sampled.

Sensitivities of the sampling and assay methods i. Properly collected control samples will help rule out extraneous contamination of the surface sample. Skip directly to site content Skip directly to page options Skip directly to A-Z link. Infection Control. Section Navigation. Facebook Twitter LinkedIn Syndicate.

Background F. Environmental Sampling Guidelines for Environmental Infection Control in Health-Care Facilities Minus Related Pages. On This Page. Box Preliminary concerns for conducting air sampling Consider the possible characteristics and conditions of the aerosol, including size range of particles, relative amount of inert material, concentration of microorganisms, and environmental factors.

Determine the type of sampling instruments, sampling time, and duration of the sampling program. Determine the number of samples to be taken. Ensure that adequate equipment and supplies are available. Determine the method of assay that will ensure optimal recovery of microorganisms.

Select a laboratory that will provide proper microbiologic support. Ensure that samples can be refrigerated if they cannot be assayed in the laboratory promptly.

Sampling methods and descriptions and samplers for each. Example use: sampling water aerosols to Legionella spp. Buffered gelatin, tryptose saline, peptone, nutrient broth Ambient temperature and humidity will influence length of collection time Chemical Corps.

All Glass Impinger AGI Impaction on solid surfaces Air drawn into the sampler; particles deposited on a dry surface Viable particles; viable organisms on non-nutrient surfaces, limited to organisms that resist drying and spores ; size measurement, and concentration over time.

Example use: sampling air for Aspergillus spp. Sieve impactors can be set up to measure particle size. Slit impactors have a rotating support stage for agar plates to allow for measurement of concentration over time. Andersen Air Sampler sieve impactor ; TDL, Cassella MK­ 2 slit impactors Sedimentation Particles and micro­ organisms settle onto surfaces via gravity Viable particles.

Example uses: sampling air for bacteria in the vicinity of and during a medical procedure; general measurements of microbial air quality. Settle plates Filtration Air drawn through a filter unit; particles trapped; 0. Example use: air sampling for Aspergillus spp.

Biotest RCS Plus Electrostatic precipitation Air drawn over an electro- statically charged surface; particles become charged Viable particles; viable organisms on non-nutrient surfaces, limited to spores and organisms that resist drying ; concentration over time Solid collecting surfaces glass, and agar 85 Yes High volume sampling rate, but equipment is complex and must be handled carefully; not practical for use in health- care settings.

particle count Volume of air to be sampled and length of time sampler is to be continuously operated Background contamination Ambient conditions Sampler collection efficiency Effort and skill required to operate sampler Availability and cost of sampler, plus back-up samplers in case of equipment malfunction Availability of auxiliary equipment and utilities e.

Chemical solutions and recommended concentration in water. Environmental surface sampling methods, descriptions, standards and references. Page last reviewed: November 5, Content source: Centers for Disease Control and Prevention , National Center for Emerging and Zoonotic Infectious Diseases NCEZID , Division of Healthcare Quality Promotion DHQP.

home Environmental Infection Control Guidelines. Get Email Updates. To receive email updates about this page, enter your email address: Email Address. What's this? Return to Guidelines Library. Provide a mapping tool that helps identify California communities that are most affected by pollution, and where people are often especially vulnerable to pollution's effects.

The Eastern Hill area near City Terrace contains two closed landfills, the Blanchard and Cogen Landfills, which were operated by BKK Corporation and have been closed since While the County never operated the landfills, after their closure the County acquired portions of the property to construct public improvements.

The County acquired about four acres on the western edge of the former Cogan Landfill to construct a portion of Sheriff's Road.

The County also acquired approximately 21 acres of the former Blanchard Landfill, where the Los Angeles County Sheriff's Department's Monterey Park facilities are located on North Eastern Avenue.

The remainder of the former landfills is privately owned. The County actively manages its portion of the landfills, including the installation and operation of landfill gas control systems on the County-owned property at both landfills.

The County has been actively managing its portion of the landfills, including installation of landfill gas control systems at both landfills. Crown Enterprises also installed a landfill gas control system at Cogen Landfill, while Bar V Bar is set to have an operational landfill gas control system installed at Cogen by the end of In tandem with the installation of the System, the County began an assessment of potential health risks in the City Terrace community.

As part of the initial sampling process, the County conducted community outreach to the homes in the City Terrace community, seeking access for soil sampling.

The outreach resulted in 29 property owners agreeing to permit subsurface soil vapor and outdoor air sampling at their properties. In August , sampling was conducted at these 29 properties. DPH's findings indicated there were no landfill impacts through the soil into the community.

Vehicle emissions from regional transportation are the primary source of benzene concentrations in indoor and outdoor air in the community. Benzene is a chemical used in the production of a wide range of industrial products, including chemicals, dyes, detergents, glues, paints, rubbers, and some plastics.

It is also produced from refining petroleum. It is also present in vehicle emissions, cigarette smoke and gasoline, and is produced in the combustion of wood and coal. Benzene occurs naturally from volcanoes and forest fires. Benzene can often be found in air near areas where petroleum products such as gasoline and fuel oil leak or are spilled into the ground.

They are less harmful than benzene. While benzene is a known human carcinogen, 1,3,5 and 1,2,4-trimethylbenzene are classified as chemicals that do not have enough information to determine if they are capable of causing cancer.

The ambient air collected as part of this study does not suggest that spending time outside of your home in this community should pose any increased risk. This study did not sample or collect any groundwater for testing.

However, it is DPHs understanding that the drinking water used in this community is supplied by approved providers and is piped in from outside of this community. There is no reason to believe that the drinking water in this community has been impacted by the chemicals detected in the soil vapor located underneath the properties.

However, it is DPHs understanding that all of the drinking water used in this community is supplied by approved providers and is piped in from outside of this community. There is no reason to suspect that the drinking water in this community has been impacted in any way by the chemicals detected in the soil vapor located underneath the properties.

The water lines are all sealed and soil vapors should not be able to get in. Soil vapor samples are collected from both the landfill and offsite locations on a monthly basis. Results are used to monitor for soil vapors that may be migrating from the Cogen Landfill. Any air purifier that has a carbon or activated carbon filter would be capable of removing gas contaminants such as benzene from the air.

This is also true of any HVAC filters with carbon or activated carbon built into the filter. There is no reimbursement for purchasing air purifiers.

Los Angeles County Public Works, Eastern Hill Landfill Information. California Solid Waste Information System.