Update of the Blood Lead Reference Value - United States, 2021.

The negative impact of lead exposure on young children and those who become pregnant is well documented but is not well known by those at highest risk from this hazard. Scientific evidence suggests that there is no known safe blood lead level (BLL), because even small amounts of lead can be harmful to a child's developing brain (1). In 2012, CDC introduced the population-based blood lead reference value (BLRV) to identify children exposed to more lead than most other children in the United States. The BLRV should be used as a guide to 1) help determine whether medical or environmental follow-up actions should be initiated for an individual child and 2) prioritize communities with the most need for primary prevention of exposure and evaluate the effectiveness of prevention efforts. The BLRV is based on the 97.5th percentile of the blood lead distribution in U.S. children aged 1-5 years from National Health and Nutrition Examination Survey (NHANES) data. NHANES is a complex, multistage survey designed to provide a nationally representative assessment of health and nutritional status of the noninstitutionalized civilian adult and child populations in the United States (2). The initial BLRV of 5 µg/dL, established in 2012, was based on data from the 2007-2008 and 2009-2010 NHANES cycles. Consistent with recommendations from a former advisory committee, this report updates CDC's BLRV in children to 3.5 µg/dL using NHANES data derived from the 2015-2016 and 2017-2018 cycles and provides helpful information to support adoption by state and local health departments, health care providers (HCPs), clinical laboratories, and others and serves as an opportunity to advance health equity and environmental justice related to preventable lead exposure. CDC recommends that public health and clinical professionals focus screening efforts on populations at high risk based on age of housing and sociodemographic risk factors. Public health and clinical professionals should collaborate to develop screening plans responsive to local conditions using local data. In the absence of such plans, universal BLL testing is recommended. In addition, jurisdictions should follow the Centers for Medicare & Medicaid Services requirement that all Medicaid-enrolled children be tested at ages 12 and 24 months or at age 24-72 months if they have not previously been screened (3).

Perspectives on Childhood Lead Exposure Prevention: Looking Back and Looking Ahead.

Lead's neurotoxic properties and potential harmful effects to humans, particularly young children, have been recognized for decades, influencing public health policies to reduce its admixture in house paint and passenger car gasoline. We signal 3 emergent trends: firearm proliferation, complex international food supply chains, and equally complex product marketing strategies, which have opened opportunities for lead exposure to children from guns and ammunition, and lead contamination in children's food and consumer goods. Readers will also be apprised of Childhood Lead Poisoning Prevention Program and education strategies cultivated and advanced by the Centers for Disease Control and Prevention and its lead prevention partners. A national governmental policy update is included, as are future considerations.

Recently Recalled Children's Products Due to Lead Hazards.

OBJECTIVE: We reviewed recent reports of recalled children's products contaminated with lead to learn more about what could be done to inform public health partners about the recalls in a timely manner to assist with broader consumer notification for proactive lead poisoning prevention efforts. METHODS: Centers for Disease Control and Prevention staff reviewed lead-related recall notices for children's products issued during June 2022 through April 2024. Recall notices were extracted from the Consumer Product Safety Commission using Really Simple Syndication feed technology to identify and capture the most current recall information. Specific product details in the database were extracted and analyzed descriptively to identify response trends and best practices. RESULTS: Centers for Disease Control and Prevention's automated tool identified 30 recalls from Consumer Product Safety Commission. Lead-contaminated toys were the most frequent type of product recalled (n = 11, 37%). Most products were manufactured in China (n = 24, 86%). Products were on the market for an average of 25 months before they were recalled. No injuries were reported. The 30 recalls resulted in a combined number of 914 598 recalled units sold. CONCLUSIONS: The current approach to protecting children from lead hazards in consumer products could be augmented by timely notifying the public health community about recalls so they can broadly disseminate information through their channels to reduce lead exposure in children. Additional steps to reduce lead contamination in children's products when sourcing raw materials and components may help to decrease the number of recalls.

State-Level Childhood Lead Poisoning Prevention Policies and Practices in the United States: 2022-2023.

OBJECTIVES: The purpose of this analysis is to better understand laws and practices guiding prevention activities in childhood lead poisoning prevention programs funded by the Centers for Disease Control and Prevention (CDC). METHODS: In 2022, CDC surveyed 62 funded programs using the Awardee Lead Profile Assessment. Information was collected about childhood lead poisoning-related laws and guidance, surveillance and prevention strategies, and program services including at what blood lead levels (BLLs) various activities are performed. Separately, CDC reviewed state health department websites to obtain information on which states implemented CDC's updated blood lead reference value. RESULTS: Awardee Lead Profile Assessment results are only reported for 47 states, the District of Columbia, and Puerto Rico. Almost all programs (96%) have laws requiring reporting of BLLs, and 51% require BLLs be reported electronically to jurisdictional health departments. Most programs (80%) prioritize areas and populations that are high risk for lead poisoning prevention activities. Approximately half of the programs (51%) have a lead elimination plan or goal. Thirty-nine percent of the programs have already implemented policies, laws, or regulations to achieve lead elimination, and 74% are in the Northeast and Midwest regions of the country. As of March 2023, 71% of the programs have implemented CDC's updated blood lead reference value, and most (65%) did so via guidance for health care providers and laboratories for what BLL should initiate case management and other services for lead-exposed children. CONCLUSIONS: Almost all programs have mandatory BLL reporting laws, and about two-thirds of the programs updated their BLLs that trigger public health action.

Effects of Blood Lead Levels <10 µg/dL in School-Age Children and Adolescents: A Scoping Review.

CONTEXT: Lead exposures among school-age children are a major public health issue. Although the harmful effects of lead exposure during the first years of life are well known, there is not as much understanding of the effects of low levels of lead exposure during later childhood. OBJECTIVES: To review the effects of blood lead levels (BLLs) <10 µg/dL in school-age children and adolescents. DATA SOURCES: We searched Medline, Embase, Global health, CINAHL, Scopus, and Environmental Science Collection databases between January 1, 2000, and May 11, 2023. STUDY SELECTION: We included peer-reviewed English-language articles that presented data on the effects of BLLs <10 µg/dL in individuals ages 5 through 18 years. DATA EXTRACTION: Data on country, population, analytic design, sample size, age, BLLs, outcomes, covariates, and results were extracted. RESULTS: Overall, 115 of 3180 screened articles met the inclusion criteria. The reported mean or median BLL was <5 µg/dL in 98 articles (85%). Of the included articles, 89 (77%) presented some evidence of an association between BLLs <10 µg/dL during school age and detrimental outcomes in a wide range of categories. The strongest evidence of an association was for the outcomes of intelligence quotient and attention-deficit/hyperactivity disorder diagnoses or behaviors. LIMITATIONS: Few articles controlled for BLLs at age <5 years, limiting conclusions about the relation between later BLLs and outcomes. CONCLUSIONS: BLLs <10 µg/dL in school-age children and adolescents may be associated with negative outcomes. This review highlights areas that could benefit from additional investigation.

Sanitarians' work with indoor-tanning businesses: findings from interviews in two major metropolitan areas.

In spite of health risks, indoor tanning is a popular practice and a growing industry. Although published studies indicate that tanning businesses' compliance with regulations is poor, no studies describe enforcement activity and the related knowledge and perceptions of environmental health professionals. As part of a larger study of indoor tanning in Minnesota and Massachusetts, both states with statutes that regulate tanning, the investigation reported in this paper involved interviews of 27 sanitarians in the Twin Cities and 30 sanitarians in the Boston metropolitan area about their awareness, experiences, and practices. Overall, Massachusetts performed better than Minnesota with respect to familiarity with regulations (93 percent versus 67 percent), routine business inspections (90 percent of agencies versus 27 percent), and priority given by agencies to indoor-tanning work-differences likely attributable to a stronger state statute. Participants in both states, however, recalled few aspects of the regulations and were able to identify few of the health risks associated with indoor tanning, and most reported receiving inadequate training. Various steps must be taken to improve environmental health work with tanning businesses, including educating the public, strengthening regulations, addressing resource issues, and training sanitarians.

Concentration and detection of caliciviruses from food contact surfaces.

Outbreaks of human Norwalk virus (NV) and Norwalk-like viruses often originate in food service establishments. No reliable method is available for the detection of these human caliciviruses on food contact surfaces. We describe a simple method for the detection of NV from stainless steel work surfaces using cultivable feline calicivirus (FCV) as a model. Stainless steel surfaces were artificially contaminated with known amounts of FCV, followed by its elution in a buffer solution. Three methods of virus elution were compared. In the first method, moistened cotton swabs or pieces of nylon filter (1MDS) were used to elute the contaminating virus. The second method consisted of flooding the contaminated surface with eluting buffer, allowing it to stay in contact for 15 min, followed by aspiration of the buffer (aspiration method) after a contact period of 15 min. The third method, the scraping-aspiration method, was similar to the aspiration method, except that the surfaces were scraped with a cell scraper before buffer aspiration. Maximum virus recovery (32 to 71%) was obtained with the scraping-aspiration method using 0.05 M glycine buffer at pH 6.5. Two methods (organic flocculation and filter adsorption elution) were compared to reduce the volume of the eluate recovered from larger surfaces. The organic flocculation method gave an average overall recovery of 55% compared to the filter-adsorption-elution method, which yielded an average recovery of only 8%. The newly developed method was validated for the detection of NV by artificial contamination of 929-cm2 stainless steel sheets with NV-positive stool samples and for the detection of the recovered virus by reverse transcription-polymerase chain reaction.

Hand washing compliance among retail food establishment workers in Minnesota.

Inadequate hand washing by food workers is an important contributing factor to foodborne disease outbreaks in retail food establishments (RFEs). We conducted a survey of RFEs to investigate the effect of hand washing training, availability of hand washing facilities, and the ability of the person in charge (PIC) to describe hand washing according to the Minnesota Food Code (food code) on workers' ability to demonstrate food code-compliant hand washing. Only 52% of the PICs could describe the hand washing procedure outlined in the food code, and only 48% of workers could demonstrate code-compliant hand washing. The most common problems observed were failure to wash for 20 s and failure to use a fingernail brush. There was a strong positive association between the PIC being a certified food manager and being able to describe the food code hand washing procedure (odds ratio [OR], 5.5; 95% confidence interval [CI], 2.2 to 13.7), and there was an even stronger association between the PIC being able to describe hand washing and workers being able to demonstrate code-compliant hand washing (OR, 15; 95% CI, 6 to 37). Significant associations were detected among correct hand washing demonstration, physical infrastructure for hand washing, and the hand washing training methods used by the establishment. However, the principal determinant of successful hand washing demonstration was the PIC's ability to describe proper hand washing procedure. These results suggest that improving hand washing practices among food workers will require interventions that address PIC knowledge of hand washing requirement and procedure and the development and implementation of effective hand washing training methods.

Effect of temperature and sanitizers on the survival of feline calicivirus, Escherichia coli, and F-specific coliphage MS2 on leafy salad vegetables.

We conducted a series of experiments to compare the survival of Escherichia coli, feline calicivirus, and F-specific coliphage MS2 on lettuce and cabbage with and without disinfection. Inoculated produce was held at 4, 25, or 37 degrees C for 21 days or was treated with different concentrations of sodium bicarbonate, chlorine bleach, peroxyacetic acid, or hydrogen peroxide. Survival was measured by the decimal reduction value (time to 90% reduction in titer) and the change in log titers of the test organisms. A stronger correlation of survival measures was observed between feline calicivirus and MS2 than between E. coli and either of the viral agents at 25 and 37 degrees C. The maximum time to detection limit for MS2 at all temperatures was 9 days, whereas feline calicivirus was detected for a maximum of 14 days at 4 degrees C. In contrast, E. coli was detectable for 21 days at 4 and 25 degrees C and for 14 days at 37 degrees C. Significant increases in E. coli titer occurred within the first 5 days, but virus titers decreased steadily throughout the experiments. E. coli was also highly susceptible to all disinfectants except 1% sodium bicarbonate and 50 ppm chlorine bleach, whereas the viruses were resistant to all four disinfectants.

Occurrence of Escherichia coli, noroviruses, and F-specific coliphages in fresh market-ready produce.

Forty samples of fresh produce collected from retail food establishments were examined to determine the occurrence of Escherichia coli, F-specific coliphages, and noroviruses. An additional six samples were collected from a restaurant undergoing investigation for a norovirus outbreak. Nineteen (48%) of the retail samples and all outbreak samples were preprocessed (cut, shredded, chopped, or peeled) at or before the point of purchase. Reverse transcription-PCR, with the use of primers JV 12 and JV 13, failed to detect norovirus RNA in any of the samples. All six outbreak samples and 13 (33%) retail samples were positive for F-specific coliphages (odds ratio undefined, P = 0.003). Processed retail samples appeared more likely to contain F-specific coliphages than unprocessed samples (odds ratio 3.8; 95% confidence interval 0.8 to 20.0). Only two (5.0%) retail samples were positive for E. coli; outbreak samples were not tested for E. coli. The results of this preliminary survey suggest that F-specific coliphages could be useful conservative indicators of fecal contamination of produce and its associated virological risks. Large-scale surveys should be conducted to confirm these findings.

Knowledge, perceptions, and environmental risk factors among Jamaican households with a history of leptospirosis.

BACKGROUND: Leptospirosis is a globally important zoonotic disease caused by pathogenic Leptospira, and outbreaks typically follow heavy rainfall and flooding. This study examined the knowledge and perceptions concerning leptospirosis, factors associated with environmental hygiene and sanitation, and the presence of Leptospira in water samples from households with or without a history of the disease in the parish of St. Mary, Jamaica. METHODS: The study employed a cross-sectional design in 43 communities within the parish of St. Mary, Jamaica between September 2008 and March 2009. Households that had at least one confirmed case of leptospirosis during the 2005 or 2007 outbreaks were assessed for living conditions, environmental hygiene, and for knowledge and risk perceptions about leptospirosis. A parallel sampling scheme was used for households with no reported cases during the outbreak years. RESULTS: Almost 97% of the participants reported having heard of leptospirosis; however, less than 40% of respondents from households with a history of leptospirosis agreed that leptospirosis was a problem in the parish. Among households without a history of leptospirosis, this perception was greater in urban/peri-urban households than in rural households (59% vs. 21%; p=0.04). Risk behaviors or living conditions were common; however, there was a high level of awareness about the health risks associated with flooding. Among households with history of leptospirosis, the perception that nothing can be done to control rodents was significantly higher (p<0.04) in rural (50%) than in urban/peri-urban (17.6%) households. Nine (4%) water samples were positive for Leptospira; 56% of these were from water stored for domestic purposes. Overall, residence in rural communities, presence of a garbage dump, and leptospiral DNA in water samples correlated with households with the history of the disease (p<0.01). CONCLUSIONS: Education of rural communities regarding leptospirosis and its prevention through proper waste disposal and rodent control should be urgently initiated.

Assessment of hygienic quality of surfaces in retail food service establishments based on microbial counts and real-time detection of ATP.

Clean food contact surfaces are important in reducing the likelihood of foodborne disease transmission. The goal of this study was to assess and compare baseline cleanliness of food contact and environmental surfaces in retail food establishments by using ATP bioluminescence (ATP-B), visual assessment, and surface contact plates. Four hundred eighty-nine surface samples were collected from three food service establishments at the University of Minnesota-Twin Cities (Minneapolis) and analyzed for either ATP (252) or total aerobic plate count bacteria (237). ATP levels ranged from a minimum of 4 relative light units (RLU; 0.60 log RLU) on a clean slicer to a maximum of 506,618 RLU (5.77 log RLU) on a dirty cutting board. The overall mean was 1,950 RLU (3.29 log RLU). Cutting boards had the highest ATP levels (mean, 5,495 RLU or 3.74 log RLU; median, 6,761 RLU or 3.83 log RLU). Of the 128 samples judged visually clean at the time of sampling, 70.3 % failed ATP-B testing. Sixty-one (26 % ) of the 237 total aerobic plate count samples yielded counts of over 125 CFU/50 cm(2) (failed), and of those that failed, 40 % were assessed as visually clean before sampling. The highest average counts in CFU/50 cm(2) were found on slicers (104) and cutting boards (87). The results of this study suggest that the current practice of evaluating food contact surface cleanliness by sight and touch to meet regulatory requirements might be inadequate. ATP-B testing may be an efficient tool to facilitate creation, implementation, and validation of more effective food contact surface cleaning in food establishments.

Effect of temperature on the survival of F-specific RNA coliphage, feline calicivirus, and Escherichia coli in chlorinated water.

We compared the survival of F-specific RNA coliphage MS2, feline calicivirus, and E. coli in normal tap water and in tap water treated to an initial concentration of 50 ppm free chlorine and held at 4 degrees C, 25 degrees C, or 37 degrees C for up to 28 days. Our aim was to determine which of these two organisms (coliphage or E. coli) was better at indicating norovirus survival under the conditions of the experiment. There was a relatively rapid decline of FCV and E. coli in 50 ppm chlorine treated water and both organisms were undetectable within one day irrespective of the temperature. In contrast, FRNA phage survived for 7 to 14 days in 50 ppm chlorine treated water at all temperatures. All organisms survived for 28 days in tap water at 4 degrees C, but FCV was undetectable on day 21 and day 7 at 25 degrees C and 37 degrees C, respectively. Greater survival of FRNA phage compared to E. coli in 50 ppm chlorine treated water suggests that these organisms should be further investigated as indicators of norovirus in depurated shellfish, sanitized produce, and treated wastewater which are all subject to high-level chlorine treatment.

Survival of F-specific RNA coliphage, feline calicivirus, and Escherichia coli in water: a comparative study.

The relationship between the survival of enteric viral pathogens and their indicators (coliform bacteria and coliphages) is not well understood. We compared the survival rates of feline calicivirus (FCV), Escherichia coli, and a male-specific RNA coliphage MS2 at 4, 25, and 37 degrees C for up to 28 days in dechlorinated water. The survival rates of E. coli and FCV, a surrogate of noroviruses (NV), had a high degree of correlation at 4 and 25 degrees C, while MS2 phage survived significantly longer (P < 0.05) at these two temperatures. At 37 degrees C, the survival rates for all three organisms were highly correlated. Decimal reduction values indicating the number of days needed for 90% reduction in titer (D values) decreased for all three organisms as storage temperatures increased. FCV had the shortest D value among all three organisms at all temperatures investigated. These findings indicate that F-specific RNA phages may be useful indicators of NV in the environment.