Revisions to Acute/Off-Nominal Limits for Benzene in Spacecraft Air.

BACKGROUND: The previous short-term (1-h and 24-h) Spacecraft Maximal Allowable Concentrations (SMACs) for benzene were established at 10 and 3 ppm by NASA in 1996, based on a study of mice in which no hematological effects were noted following two 6-h exposures to benzene. When the benzene SMACs were updated in 2008, there was no revision to the short-term SMAC limits. Rather, that effort developed a long-term SMAC (1000-d) for Exploration mission scenarios.Acute benzene exposures can cause numerous neurological effects, and long-term exposure to low levels is well-known to cause acute myeloid leukemia. Since publication of the original benzene SMACs, the National Academy of Sciences developed interim Acute Exposure Guideline Limits (AEGLs) for unintentional releases of benzene into the air. Based on the data used to establish the AEGLs, we have increased our short-term, off-nominal limits for benzene in crewed spacecraft to 40 ppm and 6.7 ppm for 1-h and 24-h, respectively.Ryder VE, Williams ES. Revisions to acute/off-nominal limits for benzene in spacecraft air. Aerosp Med Hum Perform. 2023; 94(7):544-545.

Spaceflight Maximum Allowable Concentrations for Ethyl Acetate.

INTRODUCTION: Ethyl acetate is a simple organic compound that occurs naturally and is used industrially as a solvent. It has been detected in the ISS atmosphere and is known to off-gas from building materials. As NASA astronauts have been and will be exposed to ethyl acetate during space missions, Spaceflight Maximum Allowable Concentrations (SMACs) were developed following an extensive review of the available literature.METHODS: Toxicological data relevant to SMAC development was collected from electronic databases using principles of systematic review, and from previous assessments and reviews of ethyl acetate.RESULTS: From an initial pool of over 35,000 studies, 10 were identified as studies appropriate to support SMAC development. The toxicological properties of ethyl acetate are relatively straightforward. Ethyl acetate is rapidly absorbed and converted by carboxyesterases to ethanol. At concentrations on the order of 400 ppm for 4-8 h, most volunteers experienced mild irritation but no lasting effects. In subchronic animal studies, mild sedative effects and changes in body weight and weight gain were observed at 750 ppm and above.DISCUSSION: Numerous studies were identified to support the development of both short- and long-duration SMACs. No chronic studies were available, but the high quality of the subchronic studies and the short half-life of ethyl acetate support extrapolation to longer durations.Williams ES, Ryder VE. Spaceflight maximum allowable concentrations for ethyl acetate. Aerosp Med Hum Perform. 2023; 94(1):25-33.

Spacecraft Maximum Allowable Concentrations for Hydrogen Fluoride.

BACKGROUND: Spacecraft maximum allowable concentrations (SMACs) provide guidance on allowable chemical exposures for nominal and emergency situations aboard spacecraft. SMACs are set to mitigate or preclude potential crew health effects and performance degradation. Hydrogen fluoride (HF) gas is highly irritating. Inhaled HF produces irritation primarily in the upper respiratory tract. HF is not routinely present in spacecraft atmospheres. However, it can be produced in spacecraft due to overheating or combustion events involving materials containing fluorinated organics.METHODS: Toxicological data relevant to SMAC development were collected from electronic databases using principles of systematic review, and from previous assessments and reviews of HF.RESULTS: The human inhalation data of Lund (short-term) and Largent (subchronic) showed that HF at approximately 3 ppm caused very mild respiratory irritation. NASA HF SMACs are based on these findings.DISCUSSION: The 1-h and 24-h SMACs are set at 3 ppm, a value consistent with NASA short-term SMAC criteria where crew may experience mild irritation. The 7-d, 30-d, 180-d, and 1000-d SMACs are set at 0.3 ppm to protect against any long-term crew health or performance effects that could be produced from HF exposures.Lam C-W, Ryder VE. Spacecraft maximum allowable concentrations for hydrogen fluoride. Aerosp Med Hum Perform. 2022; 93(10):746-748.

Revisions to Limits for Propylene Glycol in Spacecraft Air.

INTRODUCTION: The previous Spacecraft Maximal Allowable Concentrations (SMACs) for propylene glycol were established based on a study of rodents exposed to propylene glycol (PG) aerosol for 6 h/d, 5 d/wk for 90 d. This study has been used as the basis for the few existing limits, but all exposure concentrations were well above the saturated vapor concentration of ∼100 ppm for pure propylene glycol at room temperature. For this reason, the Environmental Protection Agency and the Agency for Toxic Substances and Disease Registry noted that the method used to generate the aerosols for the two published studies of animal exposures are not relevant to exposure conditions for the general public, and most regulatory agencies have not established inhalation limits for propylene glycol, citing lack of data. Since publication of the PG SMACs in 2008, an acute inhalation study was conducted in healthy human subjects which allows us to revise our assessment. This manuscript provides the rationale for increasing the prior limits for PG in spacecraft air from 32 and 17 ppm to 64 and 32 ppm for off-nominal scenarios/releases (1-h and 24-h limits) and from 9, 3, and 1.5 ppm to 32 ppm for all nominal timeframes (7, 30, and 180 d). Due to a lack of longer-term exposure data, NASA has elected to eliminate the 1000-d SMAC limit at this time.Ryder VE, Williams ES. Revisions to limits for propylene glycol in spacecraft air. Aerosp Med Hum Perform. 2022; 93(5):467-469.

Carcinogens in Food: Evaluating the Presence of Cadmium, Lead, in Poultry Meat in South India.

OBJECTIVE: Local chickens were spontaneously sampled and slaughtered in the central markets of Coimbatore, Erode, and Namakkal districts, South India. MATERIALS AND METHODS: Wet digestion was used to extract lead (Pb), cadmium (Cd), and zinc (Zn) in their blood and selected different organs (intestine, breast, liver, and gizzard), and their concentrations were measured using an atomic absorption spectrophotometer. RESULTS: Apart from the blood of chickens from Coimbatore and Namakkal, where Pb was not found, the concentrations of Pb in the blood and organs of chickens from the three towns ranged from 1.8 to 8.33 mg/kg, exceeding the maximum tolerance thresholds (0.1 mg/kg) in internal organs of poultry birds. Except for the intestine of chickens from the three areas, Cd was only found in the heart, blood, and gizzard of Erode chickens, as well as the liver and gizzard of Namakkal chickens, in concentrations ranging from 0.13 to 0.58. According to threshold level, the upper limit met the maximum limits (0.5 mg/kg). Zn was found in all sections of chickens from the three selected districts, with concentrations ranging from 4.96 to 174.17 mg/kg. CONCLUSION: Its concentrations were within the permissible limits (10-50 mg/kg) in some areas of certain chickens, but it surpassed the permissible limit in the liver of chicken from Coimbatore. Any organs and blood from local chickens sold in Coimbatore, Erode, and Namakkal areas can be hazardous to one's health.

Quantitative skin exposure assessment of metals: A case study.

This article provides guidance into the quantitative risk assessment of skin exposures to metals. The use of wipe sampling methodologies has been shown to be standardised and effective for skin exposure assessment to metals. However, there is a lack of guidance documents and frameworks available to evaluate the level of health risk to workers from skin exposures to metals. Adverse health effects from exposures to metals have been described in the literature (Fernández-Nieto et al. 2006; Herman et al. 2006; Kreiss et al. 1996). Monitoring of workplace exposures typically focuses on the assessment of respiratory exposures. To provide a safe workplace there is a need to ensure all routes of exposure are risk assessed and controlled. The goal of this article was to develop skin (surface) exposure limits to metals, using the construction industry as a test environment, to quantitatively assess worker health risk of skin exposures to metals. This research concluded it was not feasible to establish single quantitative skin exposure limits to metals due to the many assumptions surrounding dermal exposures. A range of acceptable exposure limits are presented.

Analysis of E.U. Rapid Alert System (RASFF) Notifications for Aflatoxins in Exported U.S. Food and Feed Products for 2010-2019.

The most common, toxic, and carcinogenic mycotoxins found in human food and animal feed are the aflatoxins (AFs). The United States is a leading exporter of various nuts, with a marketing value of $9.1 billion in 2019; the European Union countries are the major importers of U.S. nuts. In the past few years, border rejections and notifications for U.S. tree nuts and peanuts exported to the E.U. countries have increased due to AF contamination. In this work, we analyzed notifications from the "Rapid Alert System for Food and Feed (RASFF)" on U.S. food and feed products contaminated with mycotoxins, primarily AFs, for the 10-year period 2010-2019. Almost 95% of U.S. mycotoxin RASFF notifications were reported for foods and only 5% for feeds. We found that 98.9% of the U.S. food notifications on mycotoxins were due to the AF contamination in almond, peanut, and pistachio nuts. Over half of these notifications (57.9%) were due to total AF levels greater than the FDA action level in food of 20 ng g-1. The Netherlands issued 27% of the AF notifications for U.S. nuts. Border rejection was reported for more than 78% of AF notifications in U.S. nuts. All U.S. feed notifications on mycotoxins occurred due to the AF contamination. Our research contributes to better understanding the main reasons behind RASFF mycotoxins notifications of U.S. food and feed products destined to E.U. countries. Furthermore, we speculate possible causes of this problem and provide a potential solution that could minimize the number of notifications for U.S. agricultural export market.

Acceptable Limits for n-Hexane in Spacecraft Atmospheres.

INTRODUCTION:The Spacecraft Maximum Allowable Concentrations (SMACs) for C2-C9 alkanes set by NASA in 2008 under the guidance and approval of the National Research Council specifically excluded SMACs for n-hexane. Unlike other C2-C9 alkanes, n-hexane can cause polyneuropathy after metabolism in humans or rodents and so requires more stringent SMACs than the other members of this group do. This document reviews the relevant published studies of n-hexane toxicity to develop exposure duration-specific SMACs for n-hexane of 200 ppm for 1 hour, 30 ppm for 24 hours, and 2.4 ppm for 7 days, 30 days, 180 days, and 1000 days.Garcia HD. Acceptable limits for n-hexane in spacecraft atmospheres. Aerosp Med Hum Perform. 2021; 92(12):956-961.

Lead and cadmium in infant milk and cereal based formulae marketed in Nigeria: a probabilistic non-carcinogenic human health risk assessment.

BACKGROUND: There has been concern on the likelihood of contamination of infant formulae and consequent health risk in children. OBJECTIVE: This study has assessed and compared the lead and cadmium levels in infant formulae commonly consumed in Nigeria with international regulatory limits. It has also compared the estimated daily intake with Joint FAO/WHO Expert Committee on Food Additives (JECFA) and Proposition 65 Provisional Tolerable Daily Intake. MATERIAL AND METHODS: Lead and cadmium levels in 26 different brands of infant formulae purchased from stores in Port-Harcourt, Rivers state, Nigeria in January 2018 were assayed by Atomic Absorption Spectrophotometry. RESULTS: The lead and cadmium levels in milk based infant formulae ranged from 0.61-3.50 mg/kg and 0.01-0.55 mg/kg respectively whereas the range of the lead and cadmium levels in the cereal and cereal mix based were 0.29-1.95 mg/kg and 0.02-0.37 mg/kg, and 0.47-2.34 mg/kg and 0.001-0.46 mg/kg respectively. The mean lead level in the milk-based formulae (1.49 0.89 mg/kg) was slightly higher than other groups of formulae but the difference was not significant (p<0.05). The mean level of cadmium (0.17 mg/kg) in milk-based infant formulae was higher than levels in cereal and cereal mix but there was no significant statistical difference (p<0.05) between the samples. The lead and cadmium level in milk, cereal and cereal mixed based infant formulae were above the food safe limits. CONCLUSIONS: The consumption of infant formulae may add to the body burden of cadmium and lead of children with attendant public health implication. Regular monitoring and safety assessment of metals contamination of these infant formulae is advised.

Assessment of cadmium and lead content in tomatoes and tomato products.

BACKGROUND: Cadmium and lead are completely redundant in the human body and any amount of these elements ingested poses a risk of adverse health effects. In non-occupational exposure the highest amount of xenobiotics enters the body with food. Valued for their taste, universal culinary application and health benefits tomatoes and tomato products are consumed almost every day by a large proportion of society. In order to protect consumers' health it is very important to monitor cadmium and lead content in food products. OBJECTIVE: The aim of the study was the health assessment of cadmium and lead content in tomatoes and tomato products in relation to their acceptable maximum levels in the relevant legislation. MATERIAL AND METHODS: Fresh fruits of the tomato plant and tomato products (juices, purées, concentrates, sauces) were analysed. Heavy metal content (Cd, Pb) was determined by flameless atomic absorption spectrometry (AAS). Before the AAS determination the samples were subjected to pressure mineralisation using microwave energy. RESULTS: Cadmium and lead contents in the studied food products were within the allowed range (the maximum level of cadmium and lead contamination of tomatoes is 0.05 mg/kg and 0.1 mg/kg of fresh mass). The limit for cadmium was exceeded only in a canned tomato concentrate (0.064 mg/kg of fresh mass). The average cadmium content in raw tomatoes and tomato products was: 0.017 mg/kg fresh weight, and lead 0.021 mg/kg fresh weight. CONCLUSIONS: Despite the low cadmium and lead contamination of the study samples of tomatoes and tomato products, it seems desirable to constantly monitor the content of these elements in food due to their ability to accumulate in the body and the risk of adverse health effects developing after many years of exposure, even to small doses.

Artificial sweeteners in non-alcoholic beverages: Occurrence and exposure estimation of the Portuguese population.

Artificial sweeteners such as acesulfame-potassium (ACE-K). saccharin (SAC), and aspartame (ASP), play a vital role in the food industry. Despite apparent benefits, several studies report adverse reactions on consumers. EFSA is currently re-evaluating several individual sweeteners, including ASP, Ace-K and SAC that shall be completed by 31 December 2020. Our goal was to evaluate, by liquid chromatography with ultraviolet detection (LC-UV), their levels in non-alcoholic beverages from the Portuguese market (soft drinks, sport drinks, energy drinks, and nectars), and estimate the exposure of the Portuguese adolescent/adult population. ACE-K was found in 85.7% of the samples, in mean levels of 97.4 mg/L. ASP and SAC, detected in 37.5% and 33.9% of the samples, were found in averages of 161.5 and 55.0 mg/L, respectively. The maximum limits set for ASP were exceeded in one energy drink. SAC exceeded the maximum permitted level (MPL) level in 3 soft drinks based on tea extracts. In 4 samples SAC was found but not mentioned in the label, and in one of these samples exceeded the MPL. The estimated daily intake (EDI), calculated in mg per kilogram of body weight per day, of ACE-K, SAC and ASP was found to be below the acceptable daily intake (ADI), both for Portuguese adolescents and adult population. Traditional soft drinks accounted for the highest EDIs representing 1.8%, 2.3% and 0.6% for ACE-K, SAC and ASP, respectively, of the ADI. Considering the previous report in Portugal it is observed that the population is currently exposed to a greater amount of artificial sweeteners, which may indicate a trend for more artificial sweeteners' usage in order to reduce sugar intake.