Sinusitis

Study of the frequency and characteristics of chronic pancreatitis among the population of Mirny Sakha (Yakutia)

In medical practice, available laboratory tests are used to diagnose chronic pancreatitis. But tests for chronic pancreatitis - studies of blood, feces, urine, pleural fluid - only indirectly assess the exocrine (exocrine) function of the pancreas (PG) and the severity of inflammation. An accurate diagnosis involves a combination of laboratory and imaging studies: ultrasound, CT, MRI of the abdominal cavity, endoscopy.

Stool examination

The results of stool analysis evaluate pancreatic (PG) secretion - volume, concentration and activity of carbohydrates (amylase and lipase). In ointment-like feces, fatty acids, neutral fat and undigested fiber are present in increased quantities.

Determining the amount of fat in feces is not difficult, but it takes a lot of time. The daily rate of fat excretion based on the results of three stool collections is 3-4 g/day for every 100 g of neutral fat taken with food. An amount exceeding 5 g in children and 7 g in adults indicates pancreatic steatorrhea - fatty stool. False negative results may be caused by a lack of appetite or too little fat intake.

But in the chronic form of the disease, the method does not allow differentiating between exocrine pancreatic insufficiency and intestinal digestive disorders.

There is a simple test for the presence of the enzyme chymotrypsin (gastrointestinal proteinase) in feces, which evaluates the exocrine function of the pancreas. But with moderate dysfunction during a chronic disease, the method is unacceptable due to low sensitivity.

The results of stool analysis evaluate pancreatic (PG) secretion - volume, concentration and activity of carbohydrates (amylase and lipase).

The concentration of pancreatic elastase-1 (E1) in feces is a standard marker of enzyme deficiency and the dynamics of the exocrine capacity of the pancreas. Enzyme E1 is involved in digestion along with others and does not undergo changes as it moves through the intestines. Individual fluctuations in E1 in the patient's stool are small, and replacement therapy does not affect the results of the analysis. In chronic pancreatitis, in the case of exocrine insufficiency, the level of elastase in feces decreases.

Deterioration of E1 secretion in feces is due to:

chronic inflammation of the pancreas;
destruction (destruction) of the exocrine parenchyma of the organ;
hereditary dysfunction of pancreatic secretion;
disruptions in the outflow of secretions into the duodenum.

The specificity (proportion of negative results) of stool tests is 94%, sensitivity (positive result) 0-93%. In the chronic form of the disease, errors in test results are observed with mild and moderate exocrine pancreatic insufficiency.

Saliva analysis for chronic pancreatitis

Amylase is an exocrine secretory enzyme that is produced by the pancreas and saliva (60% of total serum amylase). Spectrophotometric studies of the enzyme reveal its quantitative content in saliva. The norm of amylase activity is 160-320 units. It is calculated based on the amount of 0.1% starch suspension (in ml) that the salivary enzyme can break down under given conditions.

In the chronic form of pancreatitis, an amylase test is taken more than once, since the test results initially record a moderate increase in enzyme activity, and then a decrease in amylase content.

Drawing blood for examination

Blood tests are less helpful in determining chronic pancreatitis than in confirming acute pancreatitis, but indicate increases or decreases in amylase and lipase concentrations, also reflecting increases in glucose levels. Biomaterial for a general blood test is taken from a finger, and for a biochemical test you will need venous blood.

A complete blood count to monitor treatment is performed repeatedly. It is recommended to do it at the same time and in the same condition as the primary one. Both forms of blood sampling do not require special preparation. But doctors tend to recommend that patients donate blood on an empty stomach, since the choice of diet affects the final result.

General

The results of a general blood test for chronic pancreatitis will show moderate leukocytosis - an increase in the number of leukocytes in the blood at a normal rate of 4-10 thousand / μl, sometimes an increased ESR and an increase in sugar. In severe forms of the disease, leukopenia (decreased number of white blood cells) is diagnosed. Eosinophilia is often observed - an increase in the number of eosinophils in the blood. The content of lymphocytes, which are white blood cells that provide immune protection, also increases quantitatively.

Biochemical

The results of blood biochemistry allow you to quickly assess the course of metabolic processes in the body, the functioning of organs, and the condition of blood vessels according to the key parameters of the content of the following substances in the blood:

Total bilirubin is a blood pigment. The norm is 8-20.5 µmol/l. In the pseudotumor form of chronic inflammation, the head of the pancreas enlarges, interferes with the functioning of the biliary tract, and causes stagnation of bile. An increase in pigment causes jaundice.
Alpha-amylase is the most important pancreatic enzyme that breaks down complex carbohydrates - starch - into simple sugars. Norm ≤ 220 U/l. When enzyme activity increases, exacerbation of chronic pancreatitis is diagnosed. A threefold increase in amylase indicates acute pancreatitis.
The enzyme lipase, which breaks down fats and trypsin, is a proteolytic enzyme. The norm is ≤ 60 and 25.0 ± 5.3 mg/l, respectively. An increase in their level in combination with alpha-amylase activity is a reliable sign of exacerbation of chronic pancreatitis.
AST, ALT - enzymes of amino acid metabolism. Norm ≤ 40 U/l. An increase in the indicator is characteristic of pancreatitis; a decrease in ALT means an enlarged liver.
Total protein. The norm is 64 - 84 g/l. A decrease in protein levels indicates the severity of chronic pancreatitis.

In addition to these basic indicators, the biochemical analysis contains data on creatinine (metabolite), calcium and glucose levels, alkaline phosphatase, cholesterol, GSH (pancreatic and liver protein), deviations from the norm mean problems with the liver and pancreas.

Pleural fluid assessment

The norm of pleural fluid is 0.13 ml/kg body weight. The yellowish liquid is transparent, sterile, contains a small number of cells, a minimum of protein, enzymes, fats, and lactic acid.

A sign of pancreatitis will be yellow or even yellow-green exudate, cloudy. The content of total protein, cells, albumin, lactate dehydrogenase, amylase is increased, and glucose is decreased.

Urinalysis

To determine the amylase concentration, morning urine is collected in a volume of 100-150 ml. Quantitative indicators of pancreatic amylase in urine in acute and chronic forms of the inflammatory process increase many times. Exceeding the standard (≤ 1000 U/l) is an indicator for continuing testing with other methods.

In chronic pancreatitis, a violation of the absorption of amino acids in the small intestine and their excessive excretion in the urine (hyperaminoaciduria) are recorded. To clarify, the Lasus test is used.

Features in children

In the acute period of chronic pancreatitis, a general blood test in children will reveal moderate or severe leukocytosis, an increase in ESR, and the results of biochemistry will indicate overactivity of pancreatic enzymes and hyperglycemia.

Coprogram in children includes microscopic and macroscopic assessment of stool. If there is a suspicion of infection in the stomach, liver, pancreas, large and small intestines, not a coprogram, but a bacteriological analysis of feces is performed.

Fatty feces (steatorrhea) in a child, a pathologically large amount of undigested muscle fibers (creatorrhoea) are typical signs of chronic pancreatitis.

Determining the amount of amylase in serum and urine has no practical significance for the diagnosis of chronic pancreatitis in children. If cystic fibrosis of the pancreas is suspected, a genetic test or advanced genetic diagnosis is performed.

If there are none, and the results are normal, inflammatory and destructive processes in the pancreas will continue to have a destructive effect without noticeable symptoms and with satisfactory health.

At first, there are no obvious signs of the disease in the autoimmune form of pancreatitis, although antibodies (killer cells) have already begun to destroy healthy organ tissue.

And also for pancreatitis, it is quite inaccurate, since it is similar to various diseases of the digestive tract. To determine an accurate diagnosis, separate it from other pathologies and begin treatment as quickly as possible, it is necessary to undergo a series of examinations. Tests for pancreatitis (blood, urine and feces) will determine the exact problem, the presence of the disease and the area of inflammation in the gastrointestinal tract.

Symptoms inherent in this disease

It is important to know that even the initial form of pancreatitis can develop into pancreatitis, from which about 70% of patients die.

Complete blood count for pancreatitis

Tests for acute pancreatitis or chronic types of pathology are not particularly different. So, you cannot do without taking blood, which allows you to determine the presence of inflammation in the body.

The blood characteristics of a person with this disease will be as follows:

decrease in hemoglobin and red blood cells, which occurs due to complications from pancreatitis;
high white blood cell counts, sometimes even tenfold, are a sign of inflammation in the body;
rapid erythrocyte sedimentation;
high hematocrit is a sign of disturbances in water and electrolyte balance.

Biochemical blood test for pancreatitis

The main tests for chronic or acute pancreatitis are blood biochemistry, which allows us to study the functioning of all body systems.

If a person suffers from pancreatitis, the results of the biomaterial study will be as follows:

high amylase, which is a gland enzyme and is responsible for the dissolution of starch;
high elastase, lipase and trypsin;
increased glucose levels due to lack of production;
the amount of bilirubin that will be higher than normal;
low protein levels;
high transaminase levels.

The main thing you should pay attention to when studying test results for pancreatitis is an increase in pancreatic enzymes.

General and biochemical analysis is carried out after hospitalization; further research will need to be performed only occasionally to monitor the condition. For example, constant pain and high levels of enzymes indicate that the disease is progressing, developing into an acute form.

If the patient was admitted to the hospital only a few days after the first symptoms appeared, the level of lipase, which lingers in the blood for several days, will most accurately tell about the problems.

How to determine pancreatitis using tests as accurately as possible? To diagnose gland destruction, it is better to study the level of serum elastase.

The total volume in the blood can indicate the presence of acute pancreatitis. The higher the indicator, the more areas of inflammation in the organ, which worsens the patient’s situation.

The analysis of plasma neutrophil elastase is considered the most accurate, but not every clinic can offer such a study.

It is important that elastase, in the presence of pancreatitis and inflammation, remains elevated for about 10 days. Therefore, the study can be carried out on patients who immediately went to the hospital or waited several days and only then came to the doctor.

As for preparing for the analysis, nothing special is required from the patient.

Blood should be donated on an empty stomach early in the morning. This requires venous blood, but for a general analysis, blood from a finger is sufficient.

The doctor will tell you in more detail about all the nuances of preparation.

Examination of the patient's stool

Taking and studying stool helps determine the current state of the pancreas and how it functions.

Since the deterioration of the production of digestive enzymes affects the process of fat digestion, this is clearly visible in the appearance and structure of feces.

The fact that a patient has problems with the pancreas may be indicated by:

fats in feces;
presence of food remains;
light-colored stool.

Negative changes in the functioning of the pancreas can be determined by the state of stool even without studying its composition. Since the material will be shiny, it is difficult to wash off with water from the surface, has a liquid consistency and a very unpleasant odor. This is due to the process of rotting undigested proteins.

Often, a stool test alone will not be enough and additional tests will be required, such as inserting a probe or collecting pancreatic juice.

Additional tests for pancreatitis

Laboratory research methods, along with instrumental ones, help the doctor not to make a mistake when diagnosing pancreatitis, determine the stage of the disease and its severity.

What tests are used for pancreatitis?

general clinical blood test;
blood glucose;
total protein and fractions, in particular alpha2-globulins;
cholesterol;
amylase in blood, urine, saliva;
stool analysis for scatology (coprogram);
enzyme activity (lipase, trypsin);
bilirubin level and transaminase activity;
examination of duodenal contents;
examination of effusion (inflammatory fluid from the abdominal cavity obtained during laparoscopy);
pancreatic antigen (for acute pancreatitis);

Acute pancreatitis

The clinical picture of acute pancreatitis is so typical that the results of laboratory tests are the final touch that completes the overall picture. The key indicator is an increase in the activity of the amylase enzyme - its content in the blood exceeds the norm by 4-5 times, reaching 800 units. The amount of amylase in urine can reach colossal values - 8000-16000 units, against the norm of 32-64 units.

During laparocentesis (a puncture of the abdominal wall to obtain inflammatory fluid and examine the pancreas using special equipment), an enzymatic exudate is obtained in which the activity of amylase exceeds the activity of blood amylase by 2-3 times)

Blood amylase is determined on an empty stomach; To determine urine amylase, warm, freshly released urine is used in an amount of 100-150 ml. A sharp rise in amylase is short-term, lasts for several days, then it can drop to normal values, although this does not mean the cessation of the pathological process in the inflamed gland.

If renal failure develops with acute pancreatitis, the level of amylase in the urine will not be proportional to its level in the blood.

In acute pancreatitis, the pancreatic antigen will also be positive; in case of chronic disease, this indicator does not go beyond the normal range.

Chronic pancreatitis (exacerbation)

Complete blood count - leukocytosis (increased number of white blood cells) and increased erythrocyte sedimentation rate (ESR) as a nonspecific indicator of inflammation. The leukocyte norm is up to 9x10 9 /ml, ESR is up to 15 mm/h.
Blood and urine amylase will be increased, salivary amylase will be decreased.
Blood glucose is elevated, the norm does not exceed 5.5 mmol/l.
Total cholesterol is reduced, the norm should not be lower than 3 mmol/l.
Alpha2 globulins in the blood serum are also reduced, less than 7%.
The activity of lipase (normal 22-193 U/l) and trypsin (normal 10-60 μg/l) increases, especially in combination with an increase in amylase levels. Outside of exacerbation, enzyme activity does not go beyond normal limits; with exocrine insufficiency, a decrease is observed.
In the icteric form of pancreatitis, the level of bilirubin in the blood is increased, but urobilin (the final product) in the urine does not exceed acceptable values. In addition to bilirubin, it is possible to increase the level of transaminases - ALT and AST - more than 40 units
In chronic pancreatitis, the absorption of amino acids in the small intestine is impaired and their excessive excretion in the urine is observed (hyperaminoaciduria). A special Lasus test allows you to confirm it.
A scatological examination of stool reveals undigested fiber, muscle fibers, the color is grayish, and the consistency is ointment-like.
Determination of enzyme activity directly in the duodenal contents - a thin probe is inserted into the duodenum and a 0.5% solution of hydrochloric acid is injected through it, after which six consecutive portions of the duodenal contents are examined. With exocrine insufficiency in chronic pancreatitis, a pronounced decrease in enzyme activity will be observed in all portions.

Patients suffering from chronic pancreatitis must remember that laboratory parameters must be monitored at least once every six months. This is due to the fact that destructive and inflammatory changes in the pancreas can gradually develop with minimal external manifestations of the disease and relatively satisfactory health. Then only tests can give the attending physician a true picture of the activity of pancreatitis.

The symptoms of both chronic and acute pancreatitis are nonspecific. Symptoms often do not allow doctors to make a correct diagnosis, since these manifestations are characteristic of a number of other diseases.

When performing diagnostics, analysis is of great importance. Indicators and changes in feces, urine and blood are studied, which makes it possible to determine with maximum accuracy whether there is an inflammatory process in the pancreas.

Clinical blood test

With pancreatitis, a clinical blood test plays only a supporting role. The analysis makes it possible to determine the presence of an inflammatory process. Clinical analysis also shows dehydration.

In case of pancreatitis in humans, the following features are observed in a clinical blood test:

a decrease in the number of red blood cells and hemoglobin levels, as a consequence of blood loss and a possible indicator of a hemorrhagic complication of pancreatitis;

an increase in the number of leukocytes, sometimes many times, as a result of inflammation;

An increase in hematocrit indicates an electrolyte-water imbalance.

an increase in erythrocyte sedimentation rate is a sign of an ongoing inflammatory response.

Biochemical blood test

Diagnosis of pancreatitis is not complete without a biochemical blood test. It makes it possible to determine the degree of functioning of the entire organism.

With pancreatitis, changes in the chemical composition of the blood may be observed, in particular this may be:

increase in amylase levels. Amylase is a pancreatic enzyme that breaks down starch;
increased levels of lipase, elastase, phospholipase, trypsin;
increased blood sugar levels as a result of insufficient insulin secretion;
increased levels of transaminases;
increased bilirubin is a laboratory sign that occurs if the bile ducts are blocked by an enlarged pancreas;
a decrease in the level of total protein, as a consequence of protein-energy starvation.

An increase in the amount of pancreatic enzymes, in particular amylase, is the most important criterion in diagnosing this disease.

Doctors take blood for biochemical analysis immediately after the patient is admitted to the hospital. Later, the amylase level is determined in order to monitor the dynamics of the pancreas.

An increase in the amount of pancreatic enzymes in the blood against the background of increased abdominal pain may indicate that the disease is progressing or causing some complications.

Determination of lipase in blood has much less specificity. The fact is that the amount of this enzyme becomes higher not only with pancreatitis.

Tests of more than half of patients with biliary tract pathologies and liver pathologies show an increase in lipase concentration.

However, lipase lasts longer in the blood than amylase, so it needs to be determined when a person is hospitalized only some time after the onset of symptoms of pancreatitis.

To determine pancreatic dysfunction, it is important to know the level of serum elastase. In acute pancreatitis, some amount of this enzyme is most often observed. Moreover, the more serum elastase, the larger the area of foci of necrosis in the pancreas, the worse the prognosis, and help confirm this.

The greatest accuracy for determining the extent of organ damage is found in plasma neutrophil elastase. But this method is not practiced in most laboratories; it is done only in the most modern clinics in the country.

The level of elastase, unlike other pancreatic enzymes, remains elevated in all sick people for ten days after the onset of the disease.

If we compare, at the same time an increase in amylase is recorded only in every fifth patient, the level of lipase is in no more than 45-50% of patients.

Thus, determining the level of serum elastase is an important diagnostic criterion for identifying pancreatitis in people admitted to the hospital a week or later after the onset of the first clinical symptoms.

Stool analysis

In pancreatitis, stool analysis determines the current functional level of the pancreas. When the secretion of digestive enzymes decreases, the process of fat digestion always suffers at first. These changes can be easily observed in feces. The following manifestations indicate that the exocrine function of the pancreas is impaired:

the presence of fat in stool;
undigested food debris in the stool;
If you block the bile ducts, the stool will be light.

With a noticeable violation of the exocrine function of the pancreas, changes in stool are observed with the naked eye:

Feces are difficult to flush from the walls of the toilet,
has a shiny surface,
the smell of feces is persistent and unpleasant,
stools are loose and frequent.

Such feces appear due to the rotting of undigested protein in the intestines.

It should be noted that to clarify the characteristics of the exocrine function of the gland, stool examination is not of primary importance. For this purpose, other tests for pancreatitis are most often used.

As a rule, disturbances in the activity of the pancreas are determined in another way: a probe is inserted and pancreatic juice is taken for examination.

Other tests to determine pancreatitis

A variety of laboratory tests are used to diagnose pancreatitis. Below are the most important of them:

Determination of the concentration of trypsin inhibitors in the blood. The lower their amount in the plasma, the more destructive the pancreas. Accordingly, the worse the forecast will be.

Determination of immunoreactive trypsin. Doctors prescribe this method quite infrequently, since its specificity is only 40%. This means that in 60% of cases, positive immunoreactive trypsin does not indicate pancreatitis, but another disease or disorder, for example, renal failure, or hypercortisolism, is defined as such.

Determination of trypsinogen content in urine. This is a fairly informative, highly specific and sensitive method. Here, with almost a 100% guarantee, you can make the correct diagnosis. It is used quite rarely, since it is expensive and not available in all medical institutions.

If you combine instrumental diagnostic methods and take into account the clinical manifestations of inflammation of the pancreas, then laboratory tests make it possible to quickly determine the presence of pancreatitis.

The most informative value for a gastroenterologist is provided by determining the level of enzymes in the patient’s blood. On the first day, the doctor should examine pancreatic amylase levels; after a few days, the levels of elastase and lipase are studied.

Chronic pancreatitis is a disease of the pancreas, which is characterized by inflammatory and destructive changes in the tissues of the organ. Tests for chronic pancreatitis tell the attending physician about the course of the pathological process. An important place is occupied by the value of amylase in the patient’s urine and blood.
In this article, you will learn what laboratory tests need to be performed to make sure that the disease is present.

When is it necessary to get tested for chronic pancreatitis?

As soon as the first signs of disruption of the normal functioning of the pancreas begin to appear, you should immediately go to see an experienced specialist. A gastroenterologist or therapist will prescribe a basic examination, after which, in accordance with the results obtained, he will refer for additional studies.
Analyzes are taken for the following indicators:

painful sensations in the left hypochondrium, appearing periodically, which intensify after eating and decrease during fasting or when sitting;
increased salivation;
vomiting state;
frequent belching of air or food;
decreased appetite;
increased gas formation;
diarrhea (feces are yellowish or straw-colored, with a sharply unpleasant odor, sometimes containing particles of undigested food);
weight loss;
the body gets tired quickly.

Painful sensations in the left hypochondrium are a sign of indigestion

The above conditions of the body indicate poor functioning of the pancreas, which affects well-being, impairs the ability to work, the skin becomes dry, hair falls out, and anemia develops.
The main thing is to promptly identify the pathology and begin treatment. Severe exhaustion, electrolyte imbalance and loss of vital microelements can be life-threatening.

Important! You should also know that before taking tests for chronic pancreatitis, eating is prohibited, and a few days before this you should avoid fatty and fried foods. If tests need to be taken to determine glucose levels, then you can eat food as usual, without limiting yourself.

What tests should be taken for this pathology?

The patient is required to undergo a series of tests. To obtain a complete picture of the patient’s health status, the doctor must evaluate:

general blood test;
blood glucose levels;
cholesterol level;
amylase level in blood, urine, saliva;
stool analysis;
enzyme activity (lipase, trypsin);
bilirubin level and transaminase activity;
duodenal contents;
fluid obtained during laparoscopy from the abdominal cavity (exudation examination);
test for tumor markers.

Clinical blood test

An experienced gastroenterologist can answer what tests should be taken for chronic pancreatitis.

In a general blood test to diagnose chronic pancreatitis, leukocytes, red blood cells (ESR), and the volume of enzymes are determined. The main rule is to take a general test in the morning on an empty stomach. In pathological processes, the indicators will be higher than normal and indicate a focus of inflammation in the body. Interestingly, in chronic pancreatitis, the level of enzymes does not differ in any way from those of a healthy person.

Biochemical blood test

Biochemistry allows you to determine the level of:

glucose, which is elevated (the norm should not exceed 5.5 mmol/l);
cholesterol, which is below normal (at normal 3-6 mmol/l);
pancreatic enzymes (alpha 2-globulin will be reduced).

However, in inflammatory and tumor processes, kidney diseases, it increases (normal is 7-13%), trypsin increases (normal is 10-60 mcg/l) and lipase increases (normal is 22-193 U/l).

Attention! In chronic pancreatitis, the sugar level is very dangerous, which the patient must monitor. A reading of more than 7 mmol/l indicates the presence of diabetes mellitus.

Saliva analysis

Tests that help determine symptoms of chronic pancreatitis include determining the level of amylase in saliva, which is usually low. Depending on the degree of progression of the disease, the indicators will be slightly increased or decreased.

Stool analysis

When examining stool for biochemistry, fiber is found that has not had time to be digested, muscle fibers; the color will be slightly grayish, the consistency will be ointment-like. In the presence of pancreatitis, a decrease in exocrine insufficiency is observed, which indicates reduced enzyme activity.

Urinalysis

Pancreatic amylase in urine increases many times. It is necessary to collect morning urine in a volume of 100-150 ml. The norm of pancreatic amylase is 0-50 units/l.
When taking a urine test for chronic pancreatitis, the amino acid indicator is determined, since during the disease there is excessive excretion of amino acids, which indicates poor absorption of amino acids in the small intestine. The Lasus test helps determine their presence. For research, morning urine is used, collecting the middle portion in a sterile container.

Important! In chronic pancreatitis, the level of CEA (carcinoembryonic antigen) increases by 70%.

In chronic pancreatitis, an increased level of the CA 125 marker is noted. In pancreatitis, the concentration of the CA 72-4 marker is increased.

Based on these results, a final diagnosis of the presence of chronic pancreatitis is not made. It is necessary to undergo a comprehensive examination to determine an accurate diagnosis:

Ultrasound of the abdominal organs to determine diffuse changes in the tissues of the pancreas;
x-ray to confirm pancreatic calcification;
examination using a tomograph to detect areas of necrosis or tumor;
magnetic resonance imaging for overview visualization of the pancreas;
taking a biopsy for research;
fibrogastroscopy will help to examine the pancreas in more detail.

Many patients often face the question of why, with a diagnosis of chronic pancreatitis, most tests are within normal limits. The fact is that the diagnosis of this pathology is complicated by the anatomical predisposition of the pancreas and its connection with other organs of the gastrointestinal tract.
However, a fairly extensive list of procedures performed will help the treating specialist establish the most accurate diagnosis and select adequate treatment. In order for the results to be reliable, it is necessary to strictly follow all the rules for collecting tests.

What are the preventive measures for gastrointestinal diseases?

To prevent this disease, you must adhere to proper nutrition. The diet should include all necessary vitamins and microelements. Be sure to eat fruits and vegetables. The restriction includes fatty and fried foods; you should avoid excessively salty and sweet foods. Avoid carcinogenic substances, preservatives and other chemical additives.