Phenolphthalein – inhalable fraction. Documentation of proposed values of occupational exposure limits (OELs)

2018 ◽  
Vol 34 (4(98)) ◽  
pp. 89-109
Author(s):  
Katarzyna Konieczko

Phenolphthalein is a colorless and odorless crystalline solid; in a powdered form white or pale yellow. It is non-volatile, practically insoluble in water, but it dissolves in ethanol. Phenolphthalein is not known to occur as a natural product. The synthetic substance is used as a pH indicator in laboratories, during work on metal surfaces in galvanizing plants as well as for measuring the saturation of concrete with carbon dioxide. Until the end of the 20th century, it was widely used as a component of non-prescription laxatives – in 1999 FDA removed phenolphthalein from the list of substances considered safe. In 2016 in Poland 255 enterprises were reported to work with phenolphthalein (mainly laboratories) and there were 2500 occupationally exposed people. Phenolphthalein used in therapeutic doses was well tolerated. Only a few side effects were reported: abdominal discomfort, nausea, reduced blood pressure and weakness. Chronic use of phenolphthalein resulted in widening of the colon, reduced thickness of the lining of the mucosa, gastric disorders, dehydration and electrolyte imbalance. In a 13-week study in which phenolphthalein was administered to laboratory animals with diets, mice turned out to be a more sensitive species from rats. Changes in testes and epididymides were observed in males and hypoplasia and bone marrow necrosis in males and females. The results of genotoxicity studies indicated that phenolphthalein acts as a promutagen and exerts a clastogenic effect after metabolic activation. Studies on the effect of phenolphthalein on the reproduction of animals indicated its harmful effect on reproductive functions of males. In the EU, phenolphthalein is classified as a category-2 mutagen and category-2 reproductive toxicant (due to its effect on fertility). A small increase in the risk of colorectal cancer and ovarian cancer was observed in case-control studies in patients using phenolphthalein-based laxatives (especially with intensive use of these agents), but the relationship was not statistically significant. In a 2-year NTP carcinogenicity study a significant increase in the number of benign phaeochromocytomas and adenomas of renal tubular epithelium was observed in male rats. There was also a significant increase in histiocytic sarcomas in mice of both sexes and in malignant lymphomas (of all types) and thymic lymphomas and benign ovarian tumors in females. Based on these experiments phenolphthalein has been identified as a substance reasonably anticipated as human carcinogen (NTP R). The experiment on heterozygous p53 (+/-) mice of both sexes confirmed an increase in lymphoma cases. Phenolphthalein is classified by European Union experts as a category-1B of carcinogenic substances, i.e. known or presumed human carcinogens, however the classification is largely based on animal evidence. The European Chemicals Agency (ECHA) identified phenolphthalein as a substance of very high concern (SVHC). Based on the NTP test results, the additional risk of malignant lymphoma at 8.25 mg/m3 occupational exposure to phenolphthalein for 40 years is 10-4. A concentration of 8 mg/m3 was proposed as the MAC-TWA value for phenolphthalein. Since phenolphthalein is a poorly water-soluble solid, only dust exposure of the substance will occur in the work environment, hence the proposed MAC value should concern the inhalable fraction of the substance. It is proposed to label phenolphthalein as "Carc. 1B" indicating that phenolphthalein is a category-1B carcinogen and "Ft" due to reprotoxicity. There are no bases for establishing the short-term exposure limit value (STEL) and the limit value in biological material (BEI).

2018 ◽  
Vol 34 (2(96)) ◽  
pp. 35-59 ◽  
Author(s):  
Andrzej Starek

Potassium bromate (V), (KBrO3) exists as white crystals, crystalline powder or granules. It is highly soluble in water, tasteless and odourless. Potassium bromate is a strong oxidizing agent. In the past it has been used as food additive in flour milling, as an ingredient in fish-paste in Japan, in cheese making, in beer malting, as a component of cold hair wave liquid and an oxidizing compound. Moreover, bromate is formed as a by-product of water disinfection by ozonation and is frequently detected in tap and bottled water. In fact bromate is one of the most prevalent disinfection by-product of surface water. Occupational exposure to potassium bromate occurs mainly in production plants during packaging processes. In Poland, about 1 160 persons were exposed to this compound in 2016. Bromate caused many acute poisonings by accidental ingestion, mainly among children, and more often ingested for tentative suicide by young women, especially hairdressers. In the acute phase of poisoning, gastrointestinal disturbances, irreversible hearing loss, and acute renal failure were observed. Acute renal failure was associated with hemolytic uremic syndrome. There are no data on chronic intoxication of humans by potassium bromate and epidemiological studies on this subject. On the basis of the value of median lethal dose (LD50) per os in rat, potassium bromate has been classified as a compound belonging to the category „Toxic”. Major toxic signs and symptoms in animals after a single intragastric administration of potassium bromate were tachypnea, hypothermia, diarrhea, lacrimation, suppression of locomotor movement, ataxic gait, and animals lying in a prone position. At autopsy the major findings were strong hyperemia of glandular stomach mucosa and congestion of lungs. Microscopically, necrosis and degenerative changes of the proximal tubular epithelium and hearing cells of internal ear were found. It was stated that the compound is not irritating, corrosive or sensitizing. In subchronic and chronic exposure of rodents, potassium bromate led to liver and kidney dysfunction and tubular epithelial damage. Potassium bromate had mutagenic and clastogenic effects. It induced point mutations, structural chromosome aberrations, micronuclei in polychromatic erythrocytes in male mice, DNA oxidative damage by modification of deoxyguanosine to 8-hydroxydeoxyguanosine, and DNA double-strand breakage. Potassium bromate induced neoplasms in rodents and exerted promotion effect in comparison with well-known carcinogens. Besides from preneoplastic changes, expressed by high incidences of renal cell tumors and dysplastic foci, bromate induced solid neoplasms, such as adenomas and adenocarcinomas in a rat kidney and thyroid, and mesotheliomas of peritoneum and tunica vaginalis testis. The European Union classified potassium bromate as a substance that can cause cancer (Group 1.B), whereas IARC classified it as a presumably carcinogenic agent for human (Group 2.B). In principle, effects of bromate on reproduction and ontogenetic development of offspring were not observed. Animal studies suggest that a kidney is a critical organ in the exposure to potassium bromate. The results of subchronic exposure of male rats to potassium bromate administered with drinking water were used to calculate the value of MAC-NDS. The critical effects in kidney were: an increase of organ weight and dose-dependent histopathological alterations defined as epithelium urinary tract hypertrophy. The NOAEL value is 1.5 mg/kg b.w./day. For the calculation of the maximum allowable concentration (MAC) value, 5 uncertainty factors with total value of 24 were used. Based on this estimation it is proposed to accept the MAC-TWA value for potassium bromate at 0.44 mg/m3. The risks of kidney and thyroid cancer in condition of occupational exposure are 2.2 · 10-3 and 0.6 · 10-3, respectively. There is no reason to determine the value of short-term exposure limit (STEL) and the biological exposure index (BEI). „Carc.1.B” notation (carcinogenic substance) was proposed


2021 ◽  
Vol XXXVII (1) ◽  
pp. 17-47
Author(s):  
Elżbieta Bruchajzer ◽  
Jadwiga Szymańska ◽  
Barbara Frydrych

N-Methylformamide is a colorless liquid with an ammoniacal odor, used as a solvent and an intermediate for chemical reactions. There are no data on occupational exposure in Poland. N-Methylformamide is very well absorbed into the human body. The LD50 values for N-methylformamide administered to animals in various routes are similar (2600 ÷ 4000 mg/kg bw). After single or short-term administration of the compound in doses of 100 ÷ 1200 mg/kg bw. worsening symptoms of liver damage have been observed. No-observed adverse effect concentration (NOAEC) was established at 120 mg/m3 (two-week inhalation exposure in rats). Increase of hepatotoxic effect of N-methylformamide were observed at concentrations of 320 mg/m3 and 980 mg/m3. There are no data on sub-chronic, chronic and carcinogenic effects of the compound in laboratory animals. N-Methylformamide was not mutagenic and genotoxic. It caused embryotoxic and teratogenic effects. The NOAEC value (120 mg/m3) was used as the basis for determining the MAC (maximum acceptable concentration) value for N-methylformamide, and the MAC value for N-methylformamide was calculated at 3.3 mg/m3. There are no basis to determine the short-term value (STEL) and biological limit value (BLV). It has been proposed to label the compound as "Ft" (toxic for reproduction) and "skin" (skin absorption of the substance may be as important as inhalation exposure). This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering


2018 ◽  
Vol 34 (2(96)) ◽  
pp. 61-97
Author(s):  
Elżbieta Bruchajzer ◽  
Barbara Frydrych

3,3'-Dimethylbenzidine (3,3'-DMB, DMB, o-tolidine) is a solid used (as water-soluble dihydrochloride salt (dimethylbenzidine · 2HCl)) in the production of azopigments, polyurethane elastomers and plastics for coating. Small amounts are also used in diagnostic tests in laboratories. Occupational exposure to dimethylbenzydine occurs mainly during the production and use of pigments to dye textiles, plastics, paper and leather. In 2005–2014, dimethylbenzidine was used in Poland in 18–30 workplaces, where 135–280 people each year (mainly women) were exposed. No epidemiological data and information related to toxic effects of DMB in humans was found in the available literature. The LD50 value (median lethal dose) after single intragastric administration of 3,3'-dimethylbenzidine to rats was 404 mg/kg. After repeated exposure of laboratory animals, liver, kidney, thyroid injury and hematological changes were noted. In the Ames tests with metabolic activation, it was found that metabolites of 3,3'-dimethylbenzidine show stronger mutagenic action than the parent compound. 3,3'-DMB induced also chromosome aberrations and exchange of sister chromatids in in vitro tests. Although 3,3'-dimethylbenzidine is a derivative of carcinogenic benzidine, carcinogenic effects on humans have not been proven. However, research provides data about carcinogenic effect of 3,3'-DMB in animals. After subcutaneous administration of 3,3'-dimethylbenzidine and its dihydrochloride salt in drinking water, Zymbal's and mammary glands tumors, and cancers of uterus, skin, liver, hematopoietic system, small and large intestine were observed in rats. IARC classified 3,3'-dimethylbenzidine in the 2B group (a supposed carcinogenic agent for humans), whereas ACGIH – in the A3 group (proved carcinogenic effect on animals and unknown carcinogenic effect for humans). The European Union (according to the CLP classification) has listed 3,3'-DMB in the 1B category with the inscription "H350 – can cause cancer". The permissible concentrations for 3,3'-dimethylbenzidine have been established in some European countries only (Austria, Slovenia and Switzerland) as 0.03 mg/m3. The basis of the proposed maximum concentration value (MAC-TWA) for 3,3'-dimethylbenzidine and its salts was a risk assessment of cancer in male rats chronically exposed to 3,3'-dimethylbenzidine dihydrochloride in drinking water. Taking into account the cancer risk at the level of 10-4, a concentration of 0.03 mg/m3 for the MAC-TWA value was proposed. There are no basis to determine the short-term value (STEL) and biological limit values (BLV). It was also proposed to label the compound with "Carc 1B", which indicates that it is a carcinogen category 1B, and "skin" – the absorption of substances through the skin may be as important as an inhalation route.


2019 ◽  
Vol 25 (1) ◽  
pp. 37-50 ◽  
Author(s):  
Alvin C. Alvarado ◽  
Bernardo Z. Predicala

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.


2017 ◽  
Vol 33 (1(91)) ◽  
pp. 97-113
Author(s):  
Andrzej Sapota ◽  
Małgorzata Skrzypińska-Gawrysiak ◽  
ANNA KILANOWICZ

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.


2017 ◽  
Vol 17 (8) ◽  
pp. 4957-4988 ◽  
Author(s):  
Chunlin Li ◽  
Yunjie Hu ◽  
Fei Zhang ◽  
Jianmin Chen ◽  
Zhen Ma ◽  
...  

Abstract. Multi-pollutants in smoke particulate matter (SPM) were identified and quantified for the biomass burning of five major agricultural residues (wheat, rice, corn, cotton, and soybean straw) in China by an aerosol chamber system combined with various measurement techniques. The primary emission factors (EFs) for PM1. 0 and PM2. 5 are 3.04–12.64 and 3.25–15.16 g kg−1. Organic carbon (OC), elemental carbon (EC), water-soluble inorganics (WSIs), water-soluble organic acids (WSOAs), water-soluble amine salts (WSAs), trace mineral elements (THMs), polycyclic aromatic hydrocarbons (PAHs), and phenols in smoke PM1. 0/PM2. 5 are 1.34–6.04/1.54–7.42, 0.58–2.08/0.61–2.18, 0.51–3.52/0.52–3.81, 0.13–0.64/0.14–0.77, (4.39–85.72/4.51–104.79)  ×  10−3, (11.8-51.1/14.0-131.6)  ×  10−3, (1.1–4.0/1.8–8.3)  ×  10−3, and (7.7–23.5/9.7–41.5)  ×  10−3 g kg−1, respectively. Black carbon (BC) mainly exists in PM1. 0; heavy-metal-bearing particles favour residing in the range of smoke PM1. 0−2. 5, which is also confirmed by individual particle analysis. With respect to the five scenarios of burning activities, the average emissions and overall propagation of uncertainties at the 95 % confidence interval (CI) of SPM from agricultural open burning in China in 2012 were estimated to be 1005.7 (−24.6, 33.7 %), 901.4 (−24.4, 33.5 %), 432.4 (−24.2, 33.5 %), 134.2 (−24., 34.0 %), 249.8 (−25.4, 34.9 %), 25.1 (−33.3, 41.4 %), 5.8 (−30.1, 38.5 %), 8.7 (−26.6, 35.6 %), 0.5 (−26.0, 34.9 %), and 2.7 (−26.1, 35.1 %) Gg for PM2. 5, PM1. 0, OC, EC, WSI, WSOA, WSA, THM, PAHs, and phenols , respectively. The emissions were further spatio-temporally characterized using a geographic information system (GIS) in different regions in the summer and autumn post-harvest periods. It was found that less than 25 % of the total emissions were released during the summer harvest, which was mainly contributed by the North Plain and the centre of China, especially Henan, Shandong, and Anhui, which are the top three provinces regarding smoke particle emissions. Flux concentrations of primarily emitted smoke PM2. 5 that were calculated using the box-model method based on five versions of emission inventories all exceed the carcinogenic-risk permissible exposure limits (PEL). The health impacts and health-related economic losses from the smoke PM2. 5 short-term exposure were assessed. The results show that China suffered from 7836 cases (95,% CI: 3232, 12362) of premature mortality and 7 267 237 cases (95 % CI: 2 961 487, 1 130 784) of chronic bronchitis in 2012, which led to losses of USD 8822.4 million (95 % CI: 3574.4, 13 034.2) or 0.1 % of the total GDP. We suggest that the percentage of open-burnt crop straw in the post-harvest period should be cut down by over 97 % to ensure a reduction in carcinogenicity risk, especially in the North Plain and the northeast, where the emissions should decrease at least by 94 % to meet the PEL. With such emission control, over 92 % of the mortality and morbidity attributed to agricultural fire smoke PM2. 5 can be avoided in China.


2018 ◽  
Vol 34 (4(98)) ◽  
pp. 5-40
Author(s):  
Jan Gromiec

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.


2016 ◽  
Author(s):  
Chunlin Li ◽  
Yunjie Hu ◽  
Fei Zhang ◽  
Jianmin Chen ◽  
Zhen Ma ◽  
...  

Abstract. Abstract. Multi-pollutants in smoke particulate matter (SPM) were identified and quantified for biomass burning of five major agricultural residues such as wheat, rice, corn, cotton, and soybean straws in China by aerosol chamber system combining with various measurement techniques. The primary emission factors (EFs) for PM1.0 and PM2.5 are 3.04–12.64 and 3.25–15.16 g kg−1. Organic carbon (OC), elemental carbon (EC), char-EC, soot-EC, water-soluble inorganics (WSI), water-soluble organic acids (WSOA), water-soluble amine salts (WSA), trace mineral elements (THM), polycyclic aromatic hydrocarbons (PAHs), and phenols in smoke PM1.0 / PM2.5 are, 1.34–6.04 / 1.54–7.42, 0.58–2.08 / 0.61–2.18, 0.51–1.67 / 0.56–1.76, 0.05–0.41 / 0.05–0.42, 0.51–3.52 / 0.52–3.81, 0.13–0.64 / 0.14–0.77, (4.39–85.72 / 4.51–104.79) × 10−3, (11.8–51.1 / 14.0–131.6) × 10−3, (1.1–4.0 / 1.8–8.3) × 10−3, and (7.7–23.5 / 9.7–41.5) × 10−3 g kg−1, respectively. EC and soot-EC mainly exist in PM1.0, which are confirmed by morphology analysis. Heavy metal-bearing particles favor to reside in the range of smoke PM1.0–2.5. With respect to five scenarios of burning activities or straw field burning rates, the total emissions of SPM from agricultural open burning in China in 2012 were estimated for PM2.5, PM1.0, OC, EC, char-EC, soot-EC, WSI, WSOA, WSA, THM, PAHs, and phenols to be 0.74–1.24, 0.66–1.11, 0.32–0.53, 0.10–0.16, 0.08–0.14, 0.02–0.03, 0.18–0.30, 0.019–0.031, 4.23–7.19 × 10−3, 6.36–10.64 × 10−3, 0.35–0.59 × 10−3, and 2.02–3.40 × 10−3 Tg, respectively. The emissions were further temporal-spatially characterized using geographic information system (GIS) at different regions in summer and autumn post-harvest periods. It is found less than 25 % of the total emissions were released during summer harvest period that was mainly contributed by the North Plain and the Central of China, especially Henan, Shandong, and Anhui, leading the top three provinces of smoke particle emissions. Flux concentrations of primarily emitted smoke PM2.5 that were calculated using box-model method based on five versions of emission inventories all exceed the carcinogenic risk permissible exposure limits (PEL). The health impacts and health-related economic losses from the smoke PM2.5 short-term exposure were assessed. The results show that China suffered from 7836 (95 % confidence interval (CI): 3232, 12 362) premature mortality and 7 267 237 (95 % CI: 2 961 487, 1 130 784) chronic bronchitis in 2012, which led to 8822.4 (95 % CI: 3574.4, 13034.2) million US$, or 0.1 % of the total GDP losses. We suggest that percentage of open burnt crop straws at post-harvest period should be cut down by over 97 % to ensure risk aversion from carcinogenicity, especially the North Plain and the Northeast, where the emissions should decease at least by 94 % to meet the PEL. Under such emission control, over 92 % of the mortality and morbidity attributed to agricultural fire smoke PM2.5 can be avoided in China.


F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 571
Author(s):  
Malin af Petersens ◽  
Fritiof Andersson Fenger-Krog ◽  
Jan G. Jakobsson

Background: Minimally invasive surgeries have increased dramatically during the last decades. Carbon dioxide (CO2) is the gas used for insufflation during laparoscopies, creating space and visibility. The CO2 leaks into ambient air through ports where instruments are inserted. If the CO2 reaches a certain concentration it affects personnel health. There are national occupational exposure limits (OEL) for CO2, including a level limit value (LLV) of 5000 ppm. We are not aware of any previous studies addressing occupational exposure to CO2 during laparoscopies. The aim of this study was to assess the compliance to national OELs for CO2 during laparoscopies. Methods: A gas detector was placed in the breathing zone of personnel in the operating theatre. The detector measured CO2 concentrations every tenth minute during laparoscopies in three locations. Results: During 27 laparoscopies, the measured CO2 reached a maximum concentration of 1100 ppm, less than one fourth of the LLV. Median CO2 concentration was 700 ppm. Conclusion: Results show that the occupational exposure to CO2 during laparoscopies is well below set OELs. Our findings support personnel safety associated with routine use of CO2 during laparoscopies.


2017 ◽  
Vol 33 (4(94)) ◽  
pp. 5-25
Author(s):  
Katarzyna Konieczko ◽  
JOLANTA Skowroń

Urea is a non-flammable, colorless or white crystalline solid. It has a faint aroma of ammonia and a cooling, saline taste. It is hygroscopic, very well soluble in water. During long-term storage and in aqueous solutions urea partly decomposes with the release of ammonia and carbon dioxide. Urea is used as a: component of fertilizer and animal feed; raw material for production of plastics, flame-proofing agents, adhesives, medicines, cosmetics and household products; reductant in selective catalytic reduction (SCR) systems used to reduce NOx emissions from stationary and mobile sources; deicing compound on roads, railroad tracks and airport runways; in the food industry as an additive for bakery products, alcoholic beverages and gelatine-based products and as a reagent in laboratories. In 2012, world production of urea was estimated to be around 184 million tonnes and is projected to increase further. In the European Chemicals Agency, urea was registered by 5 companies from Poland. The number of workers exposed to urea in 2 of these plants is a total of 201 people. Urea is an endogenous product, formed in the liver in the urea cycle from ammonia formed by the catabolism of amino acids and proteins, is then excreted by the kidneys. An adult man excretes about 20 ÷ 35 g of urea in the urine during the day. Most of the information on the effects of urea in humans comes from patients with renal insufficiency who have elevated urea levels. Adverse effects of urea include: headache, nausea, vomiting, syncope, confusion, electrolyte abnormalities in the blood. Urea has a slight irritating effect on the eyes and does not irritate the skin. At concentrations above 10% urea has a keratolytic effect - it facilitates peeling and increases the permeability of the stratum corneum, thereby increasing the therapeutic activity of many topical medications. Based on animal studies urea has low acute and chronic toxicity and no carcinogenic or reproductive toxicity. Urea does not meet the classification criteria as a CLP hazardous substance. Due to very low vapor pressure, exposure is possible only to urea dust. Therefore, in order to protect workers from the nuisance of particulate matter (dust) of urea, the MAC (TWA) value of 10 mg/m3 was recommended as for other dusts not classified for toxicity but posing a hazard for visibility reasons. There is no basis for determining the short-term exposure limit value (STEL) and the biological exposure index value (BEI).


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