Buy the best types of mix asphalt at a cheap price
Road pavers are exposed to polycyclic aromatic hydrocarbons (PAHs) while working with hot mix asphalt through inhalation of vapors and particulate matter (PM), as well as dermal contact with PM and contaminated surfaces.
mix asphalt
In this article, we are going to discuss why urinary system damage must be taken seriously by the exposed asphalt workers.
PAHs have been linked to cancer and other serious health issues. These particulate emissions contain several PAHs, each of which has four to six rings and is a powerful carcinogen.
Because urinary biomarkers of large PAHs are only occasionally detectable in asphalt workers, researchers have focused on the more volatile and abundant two-ring and three-ring PAHs as potential biomarkers of PAH exposure.
Particulate polycyclic aromatic compounds (P-PACs) in air and dermal patch samples from 20 road pavers were compared to urinary levels of naphthalene (two rings), phenanthrene (three rings), monohydroxylated metabolites of naphthalene and phenanthrene (OH-Nap and OH-Phe), and 1-hydroxypyrene (OH-Pyr) (four rings).
On three consecutive workdays, samples of each worker's breathing zone air (n = 55) and dermal patch (n = 56) were collected, as well as urine (n = 149) samples collected after their shift, before bed, and in the morning.
The measured levels of P-PACs and urinary analytes were used to create a statistical model of the relationships between exposure and biomarkers, with controls to account for urinary creatinine, smoking status, age, body mass index, and urine sampling timing.
There was a significant correlation between P-PAC levels in the air and OH-Phe levels in urine collected post-shift, at bedtime, and the next morning.
P-PAC measurements taken via air and dermal patch were both significant predictors of post-shift urine levels for U-Nap, U-Phe, and OH-Pyr.
Furthermore, dermal patch measurements were significant predictors of bedtime urine levels (for all three analytes) and morning urine levels (for all three analytes) (U-Nap and OH-Pyr only).
Creatine concentration was found to have a significant effect on all analytes, whereas smoking status and body mass index had a minor effect on U-Phe and OH-Pyr, respectively.
The levels of OH-Nap in air or dermal patch samples were not found to be associated with P-PAC measurements, but they were found to be significantly affected by smoking status, age, day of sample collection, and urinary creatinine levels.
Our findings suggest that biomarkers of exposure to particulate asphalt emissions such as U-Nap, U-Phe, OH-Phe, and OH-Pyr, with OH-Phe being the most promising candidate, can be used.
Indications that U-Nap, U-Phe, and OH-Pyr levels were significantly associated with dermal patch measurements well into the evening following a given work shift.
combined with the small ratios of within-person variance components to between-person variance components at bedtime, suggest that bedtime measurements may be useful for investigating dermal PAH exposures.
hot mix asphalt
Asphalt, also known as bitumen, is a petroleum product with a high viscosity that is commonly used for road paving when combined with other ingredients (such as coal tar and gravel) to produce hot mix asphalt. Asphalt is also known as bitumen.
Despite the fact that the chemical composition of asphalt varies depending on the origin of the petroleum and other components, asphalt is primarily composed of a diverse range of hydrocarbons (NIOSH, 2000).
Polycyclic aromatic hydrocarbons, or PAHs, have been the focus of most research on workers exposed to asphalt.
PAHs are a class of fused-ring aromatic compounds that contain a variety of cancer-causing substances (IARC, 1987).
The levels of polycyclic aromatic hydrocarbons (PAHs) in hot mix asphalt can vary greatly depending on the raw materials used in its manufacture and whether or not coal tar was used (Burstyn and Kromhout, 2000; Burstyn et al., 2002).
Workers are exposed to PAHs through inhalation of asphalt vapor and fumes [condensed vapor in liquid and solid form, referred to here as particulate matter (PM)] and dermal contact with PM through deposition or direct contact with contaminated surfaces.
When hot mix asphalt is applied, this exposure occurs.
In general, vapor-phase emissions from hot mix asphalt contain smaller and more volatile PAHs with two to four rings [for example, naphthalene (Nap), phenanthrene (Phe), and pyrene (Pyr)].
Particulates, on the other hand, typically contain larger species with four to six rings [for example, chrysene, benzo(a)pyrene, and benzo(a)pyrene] (g,h,i) Because hot mix asphalt particulates contain the highest levels of carcinogenic PAHs, health professionals are most concerned about asphalt workers' exposure to PM through inhalation and dermal contact.
Despite the fact that epidemiological studies point to increased cancer risks among asphalt workers that are likely related to PAH exposures (Partanen and Boffetta, 1994; Boffetta et al., 1997; Hooiveld et al., 2002; Boffetta et al., 2003a,b; Burstyn et al., 2003; Randem et al., 2004; Burstyn et al., 2003; Randem (Chiazze et al., 1991; NIOSH, 2000).
cold mix asphalt
This uncertainty can be attributed to the difficulty of accurately assessing exposures to asphalt emissions, particularly the PAH content, via mixed routes (such as air and dermal contact, as well as ingestion), as well as physical forms (i.e. vapors and particulates).
Previous research attempted to quantify asphalt exposures by collecting air and dermal patch samples in order to estimate the amount of PAHs that could be inhaled and deposited on the skin (Jongeneelen et al., 1988; McClean et al., 2004a; Vaananen et al., 2005).
These studies were carried out in an attempt to address this uncertainty.
Analytes included specific PAHs as well as several nonspecific measures of PAH exposure, such as particulate matter, benzene-soluble particulate matter, and polycyclic aromatic compounds (PACs, a group of aromatic hydrocarbons containing primarily four to six-ring PAHs and heterocyclic compounds).
Urinary biomarkers have also been used to assess PAH exposure as well as internal doses in workers exposed to asphalt.
Urinary levels of unmetabolized PAHs and monohydroxylated PAH metabolites have been linked to airborne and dermal PAH exposure in asphalt-exposed populations (Vaananen et al., 2003; McClean et al., 2004b. Campo et al., 2006a,b; Vaananen et al., 2006; Buratti et al., 2007).
Those that stand out are (Because these urinary analytes are so much more prevalent than the urinary metabolites of the larger, more cancer-causing PAH species, it is common practise to take them into account when PAH biomonitoring research is conducted.)
Only a few studies have reported the concentrations of multiple urinary PAH biomarkers, as well as the corresponding levels of PAHs or PACs in air and on dermal patch samples (Vaananen et al., 2005; Vaananen et al., 2006). Vaananen et al. published their findings.
In the course of a research study, PACs were measured on dermal patches and in air samples collected from 20 road pavers who worked with hot mix asphalt (McClean et al., 2004a).
The PAC levels differed significantly between the air and dermal patch measurements, implying that PAC exposures were expressed differently in the air and on the skin.
The PAC levels also varied significantly depending on the specific tasks performed by the pavers (McClean et al., 2004a). These same workers were studied again in a subsequent study that used urinary OH-Pyr as a biomarker of asphalt emissions exposure (McClean et al., 2004b).
The authors concluded that dermal exposure to asphalt emissions had an eightfold greater effect on OH-Pyr levels than inhalation exposure.
and that the effect of inhalation exposure was more apparent immediately after the work shift, whereas the effect of dermal exposure was more apparent 8-16 hours later.
Furthermore, the authors discovered that the effect of inhalation exposure was more noticeable immediately following the work shift (McClean et al., 2004b).
Asphalt Worker
Urinary levels of nap and phe, as well as monohydroxylated metabolites of nap, phe, and pyr, were recently measured in urine samples collected from the same 20 road pavers (Sobus et al., 2009a).
The findings showed that urinary biomarker measurements varied significantly depending on work assignment, similar to what was seen with PAC measurements in the same workers (McClean et al., 2004a; Sobus et al., 2009a).
According to the findings, nap, phe, and pyr urinary biomarkers may be appropriate exposure surrogates for measuring hot mix asphalt emissions (Sobus et al., 2009a).
The current study's goal is to create a statistical model of the relationships between urinary PAH analytes and particulate polycyclic aromatic compound (P-PAC) measurements in air and dermal patch samples from these 20 asphalt workers.
This study compares urinary analytes that may be useful biomarkers of particulate PAH exposure among asphalt-exposed workers, as well as the differences between air samples and dermal patch samples as measures of P-PAC exposure.
Furthermore, this study compares urinary analytes that may be useful biomarkers of particulate PAH exposure among asphalt-exposed workers.
These findings should aid in the design of future studies to assess exposure to particulate PAHs in asphalt emissions for hazard control and epidemiologic research.
This study included twenty male road pavers who were all residents of the Greater Boston area in the United States.
When workers were recruited, an approved protocol for the protection of human subjects was followed, and each applicant provided informed consent. The use of a questionnaire enabled the collection of data on smoking habits and physical dimensions.
Daily air samples and dermal patch samples were collected from each worker over the course of three days, beginning at the start of the workweek.
Personal air measurements of PACs were obtained using a personal sampling pump operating at 2 l min1 to draw air through a Teflon filter, according to the National Institute for Occupational Safety and Health's (NIOSH) Method 5506 (NIOSH, 1998).
(For airborne P-PACs [aP-PACs], followed by a XAD-2 sorbent tube for vapor polycyclic aromatic compounds). These measurements were then taken with a polycyclic vapor (V-PACs).
To measure the levels of P-PACs on dermal patch samples, a method described by Jongeneelen et al. (1988) and VanRooij et al. (1993) was used with only minor modifications (dP-PACs).
By attaching a soft polypropylene filter to an exposure pad, a dermal patch with an effective surface area of 8.71 cm2 was created.
The dermal patch was applied to the inside of each wrist with the adhesive backing that came with it (the average of measured PAC levels on the left and right wrists were used here).
hot mix asphalt concrete
As previously described, liquid extraction combined with high-pressure liquid chromatography was used to determine the levels of PACs in both air and dermal patch samples (McClean et al., 2004a,b).
Total airborne PACs (V-PACs plus aP-PACs) and dP-PACs had LODs of 0.2 micrograms per cubic meter and 38 nanograms per square centimeter, respectively (McClean et al., 2004a).
The precision of the method was assessed using intraclass correlation coefficients (ICCs) discovered through the analysis of replicate samples.
The intraclass correlation coefficients (ICCs) for V-PACs were 0.96 (based on eight replicate samples), 0.97 (based on twenty replicate samples), and 0.93 (based on 78 replicate samples), indicating that assay variability was low (less than 7% of total sample variability).
Urine samples were collected from each worker at the start of each workday (morning shift), the end of each workday (post-shift), and before going to bed (bedtime).
The samples collected on the first day of each subject's first week of paid employment (following a weekend off) were considered the subject's baseline samples.
Despite the fact that each morning sample was collected on a subsequent workday, it was treated as the final observation for the previous workday.
Before analysis, each urine sample was placed in a sterile polypropylene container and chilled to 20 degrees Celsius for up to seven years. The levels of creatinine found in the urine were determined using a colorimetric method (Sigma, 1984).
We were able to determine the concentrations of urinary Nap and Phe (respectively referred to as U-Nap and U-Phe) using head space-solid-phase microextraction in conjunction with gas chromatography-mass spectrometry.
Both U-Nap and U-Phe had an estimated LOD of 0.40 ng l-1, and their coefficients of variation (CVs) were 0.25 and 0.26, respectively. Both of these values were within the acceptable experimental error range (Sobus et al., 2009b).
The concentrations of 1- and 2-hydroxynaphthalene (1- and 2-OH-Nap), 1-, 2-, 3-, 4-, and 9-hydroxyphenanthrene (1-, 2-, 3-, 4-, and 9-OH-Phe), and 1-hydroxypyrene (1-OH-Pyr) were determined using solid-phase extraction in conjunction with liquid chromatography-tandem mass spectrometry (Onyemauwa et al., 2009).
The limits of quantitation (LOQs) for each of these analytes are as follows: These isomers were quantified together because they could not be separated chromatographically: 10 ng l1 for 1-OH-Nap, 1.0 ng l1 for 2-OH-Nap, 2.0 ng l1 for (2 + 3)-OH-Phe, and 5.0 ng l1 for 1-, 4-, and 9-OH-Phe and 1-OH-Pyr (Onyemauwa et al., 2009).
According to the estimates, the CVs of these analytes ranged from 0.053 to 0.27. (Onyemauwa et al., 2009).
The summed values of these monohydroxylated metabolites are of interest in this study. For example, 'OH-Nap' denotes the sum of 1- and 2-hydroxynaphthalene; 'OH-Phe' denotes the sum of 1-, 2-, 3-, 4-, and 9-hydroxyphenanthrene; and 'OH-Pyr' denotes 1-hydroxypyrene.
How useful is this article to you?
Average Score
5
/
Number of votes:
1
