Chemtrails which are known to contain heavy metals such as barium oxide and aluminum oxide, are known to be a bigger problem than once thought. Others have researched chemtrails at great length, but may not have known about the negative effects on ecology, the environment and human beings which have recently been discovered. This essay is meant to create awareness, not panic.
Have you ever been standing at a gas station pump, waiting for your vehicle to fill up out in the country in what you thought was clean, fresh air? Did you also notice the top surface of the pump housing may have been covered with rough grey dust? Much of that material can be from chemtrail fallout from aluminum and barium oxide. What goes up, must come down. And all of us are breathing it. Sickness almost always visits communities within a 1-3 days after the spraying has taken place. Headaches, coughs that won't go away, sore throats and head and upper chest congestion are not uncommon. Your body does not want this metal embedding itself in your respiratory tract. It becomes an irritant.
Recent research shows that aluminum oxide which is a heavy metal, can do far more damage to human beings than once thought. The metal can also affect plants, and is far more insidious than once thought.
EFFECTS OF ALUMINUM OXIDE ON HEART AND LUNGS
A paper written by Wardle, Lee, Akester and Braithwaite at Thiokol Corp. warns of hazards from aluminum oxide nanoparticles. In their paper they express concern that epidemiological studies suggest an association between inhaled ambient particulate material and adverse cardiopulmonary (heart and lungs) effects. The mechanisms related to this toxicity are still unclear. Their paper shows methods to control ultra-fine particles, to limit inhaled nanoparticles in humans.
EFFECTS OF ALUMINUM ON ECOLOGY
Is the government silent about the negative effects of aluminum? From the EPA website we read the following about acid effects and aluminum. The 22 page paper contains numerous references to scientific papers which are available at the EPA website:
"Acid deposition can occur in the wet or dry form and can adversely affect aquatic resources through the acidification of water bodies and watersheds. Acidification of aquatic ecosystems is of primary concern because of the adverse effects of low pH and associated high aluminum concentrations on fish and other aquatic organisms."
"Aluminum which can be toxic to organisms, is soluble at low pH and is leached from watershed soils by acidic deposition. Acidification may affect fish in several ways. The direct physiological effects of low pH and high aluminum include increased fish mortality, decreased growth, and decreased reproductive potential. The mechanism of toxicity involves impaired ion regulation at the gill. Population losses occur frequently because of recruitment failure, specifically due to increased mortality of early life stages. Changes at other trophic levels may affect fish populations by altering food availability."
"By combining information on relevant water chemistry parameters (pH, aluminum, calcium), fish toxicity models, and historical and current distributions of fish populations in the lakes and streams included dominant source of acidity in 100 percent of the acidic lakes studied. This is in stark contrast to the West region, where none of the acidic lakes studied were dominated by acid deposition (notably, the sample size of lakes for this region was small to begin with).
For acidic streams, the Mid-Atlantic Highland region contains the greatest proportion of streams whose acidic inputs are dominated by acid deposition (56 percent). This contrasts with acidic streams of Florida, where the vast majority (79 percent) are acidic primarily due to organic acids, rather than acid deposition. By combining information on relevant water chemistry parameters (pH, aluminum, calcium), fish toxicity models, and historical and current distributions of fish populations in the lakes and streams included in the National Surface Water Survey (NSWS), NAPAP investigators estimated the proportion of water bodies with water chemistry conditions that are unsuitable for survival of various fish species."
TRANSLATION: Aluminum causes problems with fish by interfering with the ability of gills to take oxygen from water. The aluminum works with acidic water to create a toxic environment for wildlife in lakes and streams. Aluminum is connected with ecological damage. And since it's a heavy metal
And who is spraying the aluminum oxide everywhere at high altitude? The government themselves. This is clearly another case of the left hand doesn't know what the right hand is doing...or perhaps it may not want to.
Other household products contain aluminum oxide such as sandpaper and other abrasives. Billions of nanoparticles are likely to be released when using sandpaper, which until now has been thought to be almost harmless. The problem would be worse when an electric sander is in use. Most people have been wearing a mask when sanding to avoid inhaling wood dust. Now we can see that the wood dust may be the least of our problems. And when sanding is done, there are countless particles of aluminum dust suspended in the air for hours, and all around the area on surfaces where sanding was taking place. Consider how the metal impairs ion regulation in the gills of fish - what harm will aluminum dust do deep in our lungs where there is also a thin blood-oxygen membrane?
EFFECTS ON PLANT GROWTH
Researchers at the New Jersey Institute of Technology have demonstrated that plants can be harmed by nanoparticles. Professor Daniel Watts (a toxicology expert) and a post-doc Ling Yang performed research, and reported that aluminum oxide nanoparticles in ground water inhibited the growth of corn, cucumbers, cabbage, carrots and soybeans. Watts warned that care must taken to prevent dispersion into the air, where they will be carried by rain into groundwater systems and stunt plant growth. Silicon dioxide (otherwise known as sand) had no effect on plant health.
According to Watts, "There was an assumption that nanoparticles had no effects on plants. But we have shown that seedlings can interact with nanoparticles such as aluminum oxide., and that they can have a harmful effect on seedlings and perhaps stunt the growth of plants." Watts and his post-doc grew seedlings in Petri dishes, using water with aluminum oxide nanoparticles. After just seven days the effects of stunted growth were measurable. 
Could aluminum also affect human fetus development via the bloodstream? We do not yet have conclusive data on this. But nanoparticles are used for scratch resistance coatings and sunscreen lotions. Ironically, the Aluminum oxide is also used as environmental catalysts used for remediating polluted soil. Exhaust systems, chimneys or smoke stacks can mix with rainwater and snow to gradually and irreversible pollute groundwater and soil. 
Oppenheimer wrote a paper many years ago how barium oxide and aluminum oxide could be dispersed at very high altitude to reflect the sun's heat back into space, would stay suspended for some period of time. But what if he was wrong? What if chemtrail spraying is the real source of the "greenhouse effect?" Is it merely a coincidence that since this aggressive world-wide spraying program began, that the poles are melting and winters are growing warmer than ever before?
Perhaps the true objective all along was to warm up the earth, and not cool it.
NOTE: Typos inside quoted remarks have been left unchanged, and are also present in the original document.
 Heart and lung risk factors (cardiopulmonary) See *AA1.2 on this webpage: http://lucy.mrs.org/meetings/fall2003/program/AbstractBookAA.pdf
 Electronic Engineering Times December 5, 2005 Issue
SOURCE and A GREAT DEAL OF INFORMATION, FACTS and PROOF: http://stopsprayingcalifornia.com/Aluminum_Oxide_Particles.php