Sentence examples for chemicals is difficult from inspiring English sources

We do not know if agricultural chemicals pose a risk to Buff-breasted Sandpipers and in general the magnitude of risk to birds posed by currently used agricultural chemicals is difficult to quantify.

However, the determination of Kow for extremely lipophilic chemicals is difficult, and reported results can cover a large range of values.

A quantitative comparison of the relative importance of the liver and bladder to activate the chemicals is difficult to make but the data indicate the ability of the bladder epithelium to activate bladder carcinogens.

First, LD studies aiming to estimate kelim of slowly eliminating chemicals are difficult to perform because subjects must be tracked over several years, and fasting to eliminate background exposure is not feasible.

For the training set, both the co-occurrence based approaco-occurrence basedbapproachroand may have conthebuted to the fact that approximately half of the target chemicals were difficult to curate (<70%), in particular aspartame, as shown in Figure 6—thapproachhe co-occurrence relations may not be thaveey points in whicontributedors are intoresthe.

The chemical is difficult to work with because it is unstable and corrodes piping; assuring a steady supply would mean building a whole new production line, Mr. Aumonier said, which the company declines to do.

Associations with a single chemical are difficult to interpret because of concomitant exposures to other POPs, although adjustment for multiple exposures may be imprecise because exposures can be strongly correlated due to similar exposure routes.

Because of the limited number of chemicals, it is difficult to quantitatively describe the structure activity relationship for maximal T4 decreases.

However, the nature of these variations is not apparent (maybe due to differences in diet, lifestyle, or exposure to other chemicals) and is difficult to explain with the available demographic data.

Although such an approach perhaps could be employed to investigate basic research areas of a select set of commodity chemicals, it is difficult to envision for regulatory scientific studies within a modernized TSCA that would need to deal with the approximately 15,000 chemicals that the U.S. EPA estimates are currently in commerce (U.S. EPA 2010a).

The term petrochemical is used to describe these chemical operations, but, because they are often carried out at the same plant as the primary distillation, the distinction between petroleum industry and chemical industry is difficult to maintain.